mainline inclusion from mainline-v6.9 commit e8aff71ca93026209dd0eab9b285e6808cd87d05 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

---------------------------------------------------------------------------

Add the minimal changes to enable objtool build on LoongArch, most of the functions are stubs to only fix the build errors when make -C tools/objtool.

This is similar with commit e52ec98c5ab1 ("objtool/powerpc: Enable objtool to be built on ppc").

Co-developed-by: Jinyang He hejinyang@loongson.cn Signed-off-by: Jinyang He hejinyang@loongson.cn Co-developed-by: Youling Tang tangyouling@loongson.cn Signed-off-by: Youling Tang tangyouling@loongson.cn Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- tools/objtool/arch/loongarch/Build | 2 + tools/objtool/arch/loongarch/decode.c | 71 +++++++++++++++++++ .../arch/loongarch/include/arch/cfi_regs.h | 22 ++++++ .../objtool/arch/loongarch/include/arch/elf.h | 30 ++++++++ .../arch/loongarch/include/arch/special.h | 33 +++++++++ tools/objtool/arch/loongarch/special.c | 15 ++++ 6 files changed, 173 insertions(+) create mode 100644 tools/objtool/arch/loongarch/Build create mode 100644 tools/objtool/arch/loongarch/decode.c create mode 100644 tools/objtool/arch/loongarch/include/arch/cfi_regs.h create mode 100644 tools/objtool/arch/loongarch/include/arch/elf.h create mode 100644 tools/objtool/arch/loongarch/include/arch/special.h create mode 100644 tools/objtool/arch/loongarch/special.c

diff --git a/tools/objtool/arch/loongarch/Build b/tools/objtool/arch/loongarch/Build new file mode 100644 index 000000000000..d24d5636a5b8 --- /dev/null +++ b/tools/objtool/arch/loongarch/Build @@ -0,0 +1,2 @@ +objtool-y += decode.o +objtool-y += special.o diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c new file mode 100644 index 000000000000..cc74ba4e0f54 --- /dev/null +++ b/tools/objtool/arch/loongarch/decode.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <string.h> +#include <objtool/check.h> + +int arch_ftrace_match(char *name) +{ + return !strcmp(name, "_mcount"); +} + +unsigned long arch_jump_destination(struct instruction *insn) +{ + return insn->offset + (insn->immediate << 2); +} + +unsigned long arch_dest_reloc_offset(int addend) +{ + return addend; +} + +bool arch_pc_relative_reloc(struct reloc *reloc) +{ + return false; +} + +bool arch_callee_saved_reg(unsigned char reg) +{ + switch (reg) { + case CFI_RA: + case CFI_FP: + case CFI_S0 ... CFI_S8: + return true; + default: + return false; + } +} + +int arch_decode_hint_reg(u8 sp_reg, int *base) +{ + return 0; +} + +int arch_decode_instruction(struct objtool_file *file, const struct section *sec, + unsigned long offset, unsigned int maxlen, + struct instruction *insn) +{ + return 0; +} + +const char *arch_nop_insn(int len) +{ + return NULL; +} + +const char *arch_ret_insn(int len) +{ + return NULL; +} + +void arch_initial_func_cfi_state(struct cfi_init_state *state) +{ + int i; + + for (i = 0; i < CFI_NUM_REGS; i++) { + state->regs[i].base = CFI_UNDEFINED; + state->regs[i].offset = 0; + } + + /* initial CFA (call frame address) */ + state->cfa.base = CFI_SP; + state->cfa.offset = 0; +} diff --git a/tools/objtool/arch/loongarch/include/arch/cfi_regs.h b/tools/objtool/arch/loongarch/include/arch/cfi_regs.h new file mode 100644 index 000000000000..d183cc8f43bf --- /dev/null +++ b/tools/objtool/arch/loongarch/include/arch/cfi_regs.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _OBJTOOL_ARCH_CFI_REGS_H +#define _OBJTOOL_ARCH_CFI_REGS_H + +#define CFI_RA 1 +#define CFI_SP 3 +#define CFI_A0 4 +#define CFI_FP 22 +#define CFI_S0 23 +#define CFI_S1 24 +#define CFI_S2 25 +#define CFI_S3 26 +#define CFI_S4 27 +#define CFI_S5 28 +#define CFI_S6 29 +#define CFI_S7 30 +#define CFI_S8 31 +#define CFI_NUM_REGS 32 + +#define CFI_BP CFI_FP + +#endif /* _OBJTOOL_ARCH_CFI_REGS_H */ diff --git a/tools/objtool/arch/loongarch/include/arch/elf.h b/tools/objtool/arch/loongarch/include/arch/elf.h new file mode 100644 index 000000000000..9623d663220e --- /dev/null +++ b/tools/objtool/arch/loongarch/include/arch/elf.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _OBJTOOL_ARCH_ELF_H +#define _OBJTOOL_ARCH_ELF_H + +/* + * See the following link for more info about ELF Relocation types: + * https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html... + */ +#ifndef R_LARCH_NONE +#define R_LARCH_NONE 0 +#endif +#ifndef R_LARCH_32 +#define R_LARCH_32 1 +#endif +#ifndef R_LARCH_64 +#define R_LARCH_64 2 +#endif +#ifndef R_LARCH_32_PCREL +#define R_LARCH_32_PCREL 99 +#endif + +#define R_NONE R_LARCH_NONE +#define R_ABS32 R_LARCH_32 +#define R_ABS64 R_LARCH_64 +#define R_DATA32 R_LARCH_32_PCREL +#define R_DATA64 R_LARCH_32_PCREL +#define R_TEXT32 R_LARCH_32_PCREL +#define R_TEXT64 R_LARCH_32_PCREL + +#endif /* _OBJTOOL_ARCH_ELF_H */ diff --git a/tools/objtool/arch/loongarch/include/arch/special.h b/tools/objtool/arch/loongarch/include/arch/special.h new file mode 100644 index 000000000000..35fc979b550a --- /dev/null +++ b/tools/objtool/arch/loongarch/include/arch/special.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _OBJTOOL_ARCH_SPECIAL_H +#define _OBJTOOL_ARCH_SPECIAL_H + +/* + * See more info about struct exception_table_entry + * in arch/loongarch/include/asm/extable.h + */ +#define EX_ENTRY_SIZE 12 +#define EX_ORIG_OFFSET 0 +#define EX_NEW_OFFSET 4 + +/* + * See more info about struct jump_entry + * in include/linux/jump_label.h + */ +#define JUMP_ENTRY_SIZE 16 +#define JUMP_ORIG_OFFSET 0 +#define JUMP_NEW_OFFSET 4 +#define JUMP_KEY_OFFSET 8 + +/* + * See more info about struct alt_instr + * in arch/loongarch/include/asm/alternative.h + */ +#define ALT_ENTRY_SIZE 12 +#define ALT_ORIG_OFFSET 0 +#define ALT_NEW_OFFSET 4 +#define ALT_FEATURE_OFFSET 8 +#define ALT_ORIG_LEN_OFFSET 10 +#define ALT_NEW_LEN_OFFSET 11 + +#endif /* _OBJTOOL_ARCH_SPECIAL_H */ diff --git a/tools/objtool/arch/loongarch/special.c b/tools/objtool/arch/loongarch/special.c new file mode 100644 index 000000000000..9bba1e9318e0 --- /dev/null +++ b/tools/objtool/arch/loongarch/special.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <objtool/special.h> + +bool arch_support_alt_relocation(struct special_alt *special_alt, + struct instruction *insn, + struct reloc *reloc) +{ + return false; +} + +struct reloc *arch_find_switch_table(struct objtool_file *file, + struct instruction *insn) +{ + return NULL; +}

mainline inclusion from mainline-v6.9 commit b8e85e6f3a09fc56b0ff574887798962ef8a8f80 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

---------------------------------------------------------------------------

Move init_orc_entry(), write_orc_entry(), reg_name(), orc_type_name() and print_reg() from generic orc_gen.c and orc_dump.c to arch-specific orc.c, then introduce a new function orc_print_dump() to print info.

This is preparation for later patch, no functionality change.

Co-developed-by: Jinyang He hejinyang@loongson.cn Signed-off-by: Jinyang He hejinyang@loongson.cn Co-developed-by: Youling Tang tangyouling@loongson.cn Signed-off-by: Youling Tang tangyouling@loongson.cn Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- tools/objtool/arch/x86/Build | 1 + tools/objtool/arch/x86/orc.c | 188 ++++++++++++++++++++++++++++ tools/objtool/include/objtool/orc.h | 14 +++ tools/objtool/orc_dump.c | 69 +--------- tools/objtool/orc_gen.c | 113 +---------------- 5 files changed, 206 insertions(+), 179 deletions(-) create mode 100644 tools/objtool/arch/x86/orc.c create mode 100644 tools/objtool/include/objtool/orc.h

diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build index 9f7869b5c5e0..3dedb2fd8f3a 100644 --- a/tools/objtool/arch/x86/Build +++ b/tools/objtool/arch/x86/Build @@ -1,5 +1,6 @@ objtool-y += special.o objtool-y += decode.o +objtool-y += orc.o

inat_tables_script = ../arch/x86/tools/gen-insn-attr-x86.awk inat_tables_maps = ../arch/x86/lib/x86-opcode-map.txt diff --git a/tools/objtool/arch/x86/orc.c b/tools/objtool/arch/x86/orc.c new file mode 100644 index 000000000000..b6cd943e87f9 --- /dev/null +++ b/tools/objtool/arch/x86/orc.c @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <linux/objtool_types.h> +#include <asm/orc_types.h> + +#include <objtool/check.h> +#include <objtool/orc.h> +#include <objtool/warn.h> +#include <objtool/endianness.h> + +int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn) +{ + struct cfi_reg *bp = &cfi->regs[CFI_BP]; + + memset(orc, 0, sizeof(*orc)); + + if (!cfi) { + /* + * This is usually either unreachable nops/traps (which don't + * trigger unreachable instruction warnings), or + * STACK_FRAME_NON_STANDARD functions. + */ + orc->type = ORC_TYPE_UNDEFINED; + return 0; + } + + switch (cfi->type) { + case UNWIND_HINT_TYPE_UNDEFINED: + orc->type = ORC_TYPE_UNDEFINED; + return 0; + case UNWIND_HINT_TYPE_END_OF_STACK: + orc->type = ORC_TYPE_END_OF_STACK; + return 0; + case UNWIND_HINT_TYPE_CALL: + orc->type = ORC_TYPE_CALL; + break; + case UNWIND_HINT_TYPE_REGS: + orc->type = ORC_TYPE_REGS; + break; + case UNWIND_HINT_TYPE_REGS_PARTIAL: + orc->type = ORC_TYPE_REGS_PARTIAL; + break; + default: + WARN_INSN(insn, "unknown unwind hint type %d", cfi->type); + return -1; + } + + orc->signal = cfi->signal; + + switch (cfi->cfa.base) { + case CFI_SP: + orc->sp_reg = ORC_REG_SP; + break; + case CFI_SP_INDIRECT: + orc->sp_reg = ORC_REG_SP_INDIRECT; + break; + case CFI_BP: + orc->sp_reg = ORC_REG_BP; + break; + case CFI_BP_INDIRECT: + orc->sp_reg = ORC_REG_BP_INDIRECT; + break; + case CFI_R10: + orc->sp_reg = ORC_REG_R10; + break; + case CFI_R13: + orc->sp_reg = ORC_REG_R13; + break; + case CFI_DI: + orc->sp_reg = ORC_REG_DI; + break; + case CFI_DX: + orc->sp_reg = ORC_REG_DX; + break; + default: + WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base); + return -1; + } + + switch (bp->base) { + case CFI_UNDEFINED: + orc->bp_reg = ORC_REG_UNDEFINED; + break; + case CFI_CFA: + orc->bp_reg = ORC_REG_PREV_SP; + break; + case CFI_BP: + orc->bp_reg = ORC_REG_BP; + break; + default: + WARN_INSN(insn, "unknown BP base reg %d", bp->base); + return -1; + } + + orc->sp_offset = cfi->cfa.offset; + orc->bp_offset = bp->offset; + + return 0; +} + +int write_orc_entry(struct elf *elf, struct section *orc_sec, + struct section *ip_sec, unsigned int idx, + struct section *insn_sec, unsigned long insn_off, + struct orc_entry *o) +{ + struct orc_entry *orc; + + /* populate ORC data */ + orc = (struct orc_entry *)orc_sec->data->d_buf + idx; + memcpy(orc, o, sizeof(*orc)); + orc->sp_offset = bswap_if_needed(elf, orc->sp_offset); + orc->bp_offset = bswap_if_needed(elf, orc->bp_offset); + + /* populate reloc for ip */ + if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx, + insn_sec, insn_off)) + return -1; + + return 0; +} + +static const char *reg_name(unsigned int reg) +{ + switch (reg) { + case ORC_REG_PREV_SP: + return "prevsp"; + case ORC_REG_DX: + return "dx"; + case ORC_REG_DI: + return "di"; + case ORC_REG_BP: + return "bp"; + case ORC_REG_SP: + return "sp"; + case ORC_REG_R10: + return "r10"; + case ORC_REG_R13: + return "r13"; + case ORC_REG_BP_INDIRECT: + return "bp(ind)"; + case ORC_REG_SP_INDIRECT: + return "sp(ind)"; + default: + return "?"; + } +} + +static const char *orc_type_name(unsigned int type) +{ + switch (type) { + case ORC_TYPE_UNDEFINED: + return "(und)"; + case ORC_TYPE_END_OF_STACK: + return "end"; + case ORC_TYPE_CALL: + return "call"; + case ORC_TYPE_REGS: + return "regs"; + case ORC_TYPE_REGS_PARTIAL: + return "regs (partial)"; + default: + return "?"; + } +} + +static void print_reg(unsigned int reg, int offset) +{ + if (reg == ORC_REG_BP_INDIRECT) + printf("(bp%+d)", offset); + else if (reg == ORC_REG_SP_INDIRECT) + printf("(sp)%+d", offset); + else if (reg == ORC_REG_UNDEFINED) + printf("(und)"); + else + printf("%s%+d", reg_name(reg), offset); +} + +void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i) +{ + printf("type:%s", orc_type_name(orc[i].type)); + + printf(" sp:"); + print_reg(orc[i].sp_reg, bswap_if_needed(dummy_elf, orc[i].sp_offset)); + + printf(" bp:"); + print_reg(orc[i].bp_reg, bswap_if_needed(dummy_elf, orc[i].bp_offset)); + + printf(" signal:%d\n", orc[i].signal); +} diff --git a/tools/objtool/include/objtool/orc.h b/tools/objtool/include/objtool/orc.h new file mode 100644 index 000000000000..15a32def1071 --- /dev/null +++ b/tools/objtool/include/objtool/orc.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _OBJTOOL_ORC_H +#define _OBJTOOL_ORC_H + +#include <objtool/check.h> + +int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn); +void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i); +int write_orc_entry(struct elf *elf, struct section *orc_sec, + struct section *ip_sec, unsigned int idx, + struct section *insn_sec, unsigned long insn_off, + struct orc_entry *o); + +#endif /* _OBJTOOL_ORC_H */ diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c index 0e183bb1c720..a62247efb64f 100644 --- a/tools/objtool/orc_dump.c +++ b/tools/objtool/orc_dump.c @@ -6,65 +6,10 @@ #include <unistd.h> #include <asm/orc_types.h> #include <objtool/objtool.h> +#include <objtool/orc.h> #include <objtool/warn.h> #include <objtool/endianness.h>

-static const char *reg_name(unsigned int reg) -{ - switch (reg) { - case ORC_REG_PREV_SP: - return "prevsp"; - case ORC_REG_DX: - return "dx"; - case ORC_REG_DI: - return "di"; - case ORC_REG_BP: - return "bp"; - case ORC_REG_SP: - return "sp"; - case ORC_REG_R10: - return "r10"; - case ORC_REG_R13: - return "r13"; - case ORC_REG_BP_INDIRECT: - return "bp(ind)"; - case ORC_REG_SP_INDIRECT: - return "sp(ind)"; - default: - return "?"; - } -} - -static const char *orc_type_name(unsigned int type) -{ - switch (type) { - case ORC_TYPE_UNDEFINED: - return "(und)"; - case ORC_TYPE_END_OF_STACK: - return "end"; - case ORC_TYPE_CALL: - return "call"; - case ORC_TYPE_REGS: - return "regs"; - case ORC_TYPE_REGS_PARTIAL: - return "regs (partial)"; - default: - return "?"; - } -} - -static void print_reg(unsigned int reg, int offset) -{ - if (reg == ORC_REG_BP_INDIRECT) - printf("(bp%+d)", offset); - else if (reg == ORC_REG_SP_INDIRECT) - printf("(sp)%+d", offset); - else if (reg == ORC_REG_UNDEFINED) - printf("(und)"); - else - printf("%s%+d", reg_name(reg), offset); -} - int orc_dump(const char *_objname) { int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0; @@ -205,17 +150,7 @@ int orc_dump(const char *_objname) printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i])); }

- printf("type:%s", orc_type_name(orc[i].type)); - - printf(" sp:"); - - print_reg(orc[i].sp_reg, bswap_if_needed(&dummy_elf, orc[i].sp_offset)); - - printf(" bp:"); - - print_reg(orc[i].bp_reg, bswap_if_needed(&dummy_elf, orc[i].bp_offset)); - - printf(" signal:%d\n", orc[i].signal); + orc_print_dump(&dummy_elf, orc, i); }

elf_end(elf); diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c index bae343908867..922e6aac7cea 100644 --- a/tools/objtool/orc_gen.c +++ b/tools/objtool/orc_gen.c @@ -10,121 +10,10 @@ #include <asm/orc_types.h>

#include <objtool/check.h> +#include <objtool/orc.h> #include <objtool/warn.h> #include <objtool/endianness.h>

-static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, - struct instruction *insn) -{ - struct cfi_reg *bp = &cfi->regs[CFI_BP]; - - memset(orc, 0, sizeof(*orc)); - - if (!cfi) { - /* - * This is usually either unreachable nops/traps (which don't - * trigger unreachable instruction warnings), or - * STACK_FRAME_NON_STANDARD functions. - */ - orc->type = ORC_TYPE_UNDEFINED; - return 0; - } - - switch (cfi->type) { - case UNWIND_HINT_TYPE_UNDEFINED: - orc->type = ORC_TYPE_UNDEFINED; - return 0; - case UNWIND_HINT_TYPE_END_OF_STACK: - orc->type = ORC_TYPE_END_OF_STACK; - return 0; - case UNWIND_HINT_TYPE_CALL: - orc->type = ORC_TYPE_CALL; - break; - case UNWIND_HINT_TYPE_REGS: - orc->type = ORC_TYPE_REGS; - break; - case UNWIND_HINT_TYPE_REGS_PARTIAL: - orc->type = ORC_TYPE_REGS_PARTIAL; - break; - default: - WARN_INSN(insn, "unknown unwind hint type %d", cfi->type); - return -1; - } - - orc->signal = cfi->signal; - - switch (cfi->cfa.base) { - case CFI_SP: - orc->sp_reg = ORC_REG_SP; - break; - case CFI_SP_INDIRECT: - orc->sp_reg = ORC_REG_SP_INDIRECT; - break; - case CFI_BP: - orc->sp_reg = ORC_REG_BP; - break; - case CFI_BP_INDIRECT: - orc->sp_reg = ORC_REG_BP_INDIRECT; - break; - case CFI_R10: - orc->sp_reg = ORC_REG_R10; - break; - case CFI_R13: - orc->sp_reg = ORC_REG_R13; - break; - case CFI_DI: - orc->sp_reg = ORC_REG_DI; - break; - case CFI_DX: - orc->sp_reg = ORC_REG_DX; - break; - default: - WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base); - return -1; - } - - switch (bp->base) { - case CFI_UNDEFINED: - orc->bp_reg = ORC_REG_UNDEFINED; - break; - case CFI_CFA: - orc->bp_reg = ORC_REG_PREV_SP; - break; - case CFI_BP: - orc->bp_reg = ORC_REG_BP; - break; - default: - WARN_INSN(insn, "unknown BP base reg %d", bp->base); - return -1; - } - - orc->sp_offset = cfi->cfa.offset; - orc->bp_offset = bp->offset; - - return 0; -} - -static int write_orc_entry(struct elf *elf, struct section *orc_sec, - struct section *ip_sec, unsigned int idx, - struct section *insn_sec, unsigned long insn_off, - struct orc_entry *o) -{ - struct orc_entry *orc; - - /* populate ORC data */ - orc = (struct orc_entry *)orc_sec->data->d_buf + idx; - memcpy(orc, o, sizeof(*orc)); - orc->sp_offset = bswap_if_needed(elf, orc->sp_offset); - orc->bp_offset = bswap_if_needed(elf, orc->bp_offset); - - /* populate reloc for ip */ - if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx, - insn_sec, insn_off)) - return -1; - - return 0; -} - struct orc_list_entry { struct list_head list; struct orc_entry orc;

mainline inclusion from mainline-v6.9 commit d5ab2bc36c6b0ce2f3409f934ff9cdf6d6768fa2 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

---------------------------------------------------------------------------

When update the latest upstream gcc and binutils, it generates more objtool warnings on LoongArch, like this:

init/main.o: warning: objtool: unexpected relocation symbol type in .rela.discard.unreachable

We can see that the reloc sym name is local label instead of section in relocation section '.rela.discard.unreachable', in this case, the reloc sym type is STT_NOTYPE instead of STT_SECTION.

As suggested by Peter Zijlstra, we add a "local_label" member in struct symbol, then set it as true if symbol type is STT_NOTYPE and symbol name starts with ".L" string in classify_symbols().

Let's check reloc->sym->local_label to not return -1 in add_dead_ends(), and also use reloc->sym->offset instead of reloc addend which is 0 to find the corresponding instruction. At the same time, let's replace the variable "addend" with "offset" to reflect the reality.

Here are some detailed info: [fedora@linux 6.8.test]$ gcc --version gcc (GCC) 14.0.1 20240129 (experimental) [fedora@linux 6.8.test]$ as --version GNU assembler (GNU Binutils) 2.42.50.20240129 [fedora@linux 6.8.test]$ readelf -r init/main.o | grep -A 2 "rela.discard.unreachable" Relocation section '.rela.discard.unreachable' at offset 0x6028 contains 1 entry: Offset Info Type Sym. Value Sym. Name + Addend 000000000000 00d900000063 R_LARCH_32_PCREL 00000000000002c4 .L500^B1 + 0

Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- tools/objtool/check.c | 40 +++++++++++++++++------------ tools/objtool/include/objtool/elf.h | 1 + 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c index e3fc263b1b20..a85d58d6e03f 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -20,6 +20,7 @@ #include <linux/hashtable.h> #include <linux/kernel.h> #include <linux/static_call_types.h> +#include <linux/string.h>

struct alternative { struct alternative *next; @@ -584,7 +585,7 @@ static int add_dead_ends(struct objtool_file *file) struct section *rsec; struct reloc *reloc; struct instruction *insn; - s64 addend; + unsigned long offset;

/* * Check for manually annotated dead ends. @@ -594,27 +595,28 @@ static int add_dead_ends(struct objtool_file *file) goto reachable;

for_each_reloc(rsec, reloc) { - - if (reloc->sym->type != STT_SECTION) { + if (reloc->sym->type == STT_SECTION) { + offset = reloc_addend(reloc); + } else if (reloc->sym->local_label) { + offset = reloc->sym->offset; + } else { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; }

- addend = reloc_addend(reloc); - - insn = find_insn(file, reloc->sym->sec, addend); + insn = find_insn(file, reloc->sym->sec, offset); if (insn) insn = prev_insn_same_sec(file, insn); - else if (addend == reloc->sym->sec->sh.sh_size) { + else if (offset == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; } } else { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; }

@@ -633,27 +635,28 @@ static int add_dead_ends(struct objtool_file *file) return 0;

for_each_reloc(rsec, reloc) { - - if (reloc->sym->type != STT_SECTION) { + if (reloc->sym->type == STT_SECTION) { + offset = reloc_addend(reloc); + } else if (reloc->sym->local_label) { + offset = reloc->sym->offset; + } else { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; }

- addend = reloc_addend(reloc); - - insn = find_insn(file, reloc->sym->sec, addend); + insn = find_insn(file, reloc->sym->sec, offset); if (insn) insn = prev_insn_same_sec(file, insn); - else if (addend == reloc->sym->sec->sh.sh_size) { + else if (offset == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; } } else { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; }

@@ -2506,6 +2509,9 @@ static int classify_symbols(struct objtool_file *file) struct symbol *func;

for_each_sym(file, func) { + if (func->type == STT_NOTYPE && strstarts(func->name, ".L")) + func->local_label = true; + if (func->bind != STB_GLOBAL) continue;

diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 9f71e988eca4..2b8a69de4db8 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -67,6 +67,7 @@ struct symbol { u8 profiling_func : 1; u8 warned : 1; u8 embedded_insn : 1; + u8 local_label : 1; struct list_head pv_target; struct reloc *relocs; };

mainline inclusion from mainline-v6.9 commit cb8a2ef0848ca80d67d6d56e2df757cfdf6b3355 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

---------------------------------------------------------------------------

The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is similar in concept to a DWARF unwinder. The difference is that the format of the ORC data is much simpler than DWARF, which in turn allows the ORC unwinder to be much simpler and faster.

The ORC data consists of unwind tables which are generated by objtool. After analyzing all the code paths of a .o file, it determines information about the stack state at each instruction address in the file and outputs that information to the .orc_unwind and .orc_unwind_ip sections.

The per-object ORC sections are combined at link time and are sorted and post-processed at boot time. The unwinder uses the resulting data to correlate instruction addresses with their stack states at run time.

Most of the logic are similar with x86, in order to get ra info before ra is saved into stack, add ra_reg and ra_offset into orc_entry. At the same time, modify some arch-specific code to silence the objtool warnings.

Co-developed-by: Jinyang He hejinyang@loongson.cn Signed-off-by: Jinyang He hejinyang@loongson.cn Co-developed-by: Youling Tang tangyouling@loongson.cn Signed-off-by: Youling Tang tangyouling@loongson.cn Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/loongarch/Kconfig | 2 + arch/loongarch/Kconfig.debug | 11 + arch/loongarch/Makefile | 23 +- arch/loongarch/include/asm/Kbuild | 2 + arch/loongarch/include/asm/bug.h | 1 + arch/loongarch/include/asm/exception.h | 2 + arch/loongarch/include/asm/module.h | 7 + arch/loongarch/include/asm/orc_header.h | 18 + arch/loongarch/include/asm/orc_lookup.h | 31 ++ arch/loongarch/include/asm/orc_types.h | 58 +++ arch/loongarch/include/asm/stackframe.h | 3 + arch/loongarch/include/asm/unwind.h | 20 +- arch/loongarch/include/asm/unwind_hints.h | 28 ++ arch/loongarch/kernel/Makefile | 4 + arch/loongarch/kernel/entry.S | 5 + arch/loongarch/kernel/fpu.S | 7 + arch/loongarch/kernel/genex.S | 6 + arch/loongarch/kernel/lbt.S | 3 + arch/loongarch/kernel/mcount_dyn.S | 6 + arch/loongarch/kernel/module.c | 22 +- arch/loongarch/kernel/relocate_kernel.S | 7 +- arch/loongarch/kernel/rethook_trampoline.S | 1 + arch/loongarch/kernel/setup.c | 2 + arch/loongarch/kernel/stacktrace.c | 1 + arch/loongarch/kernel/traps.c | 42 +- arch/loongarch/kernel/unwind_orc.c | 528 +++++++++++++++++++++ arch/loongarch/kernel/vmlinux.lds.S | 3 + arch/loongarch/kvm/switch.S | 9 +- arch/loongarch/lib/clear_user.S | 3 + arch/loongarch/lib/copy_user.S | 3 + arch/loongarch/lib/memcpy.S | 3 + arch/loongarch/lib/memset.S | 3 + arch/loongarch/mm/tlb.c | 27 +- arch/loongarch/mm/tlbex.S | 9 + arch/loongarch/vdso/Makefile | 1 + include/linux/compiler.h | 9 + scripts/Makefile | 7 +- 37 files changed, 875 insertions(+), 42 deletions(-) create mode 100644 arch/loongarch/include/asm/orc_header.h create mode 100644 arch/loongarch/include/asm/orc_lookup.h create mode 100644 arch/loongarch/include/asm/orc_types.h create mode 100644 arch/loongarch/include/asm/unwind_hints.h create mode 100644 arch/loongarch/kernel/unwind_orc.c

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 710ec4831887..24880542a1e8 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -137,6 +137,7 @@ config LOONGARCH select HAVE_KVM select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI + select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS select HAVE_PCI select HAVE_PERF_EVENTS select HAVE_PERF_REGS @@ -147,6 +148,7 @@ config LOONGARCH select HAVE_SAMPLE_FTRACE_DIRECT select HAVE_SAMPLE_FTRACE_DIRECT_MULTI select HAVE_SETUP_PER_CPU_AREA if NUMA + select HAVE_STACK_VALIDATION if HAVE_OBJTOOL select HAVE_STACKPROTECTOR select ARCH_HAS_PHYS_TO_DMA select HAVE_SYSCALL_TRACEPOINTS diff --git a/arch/loongarch/Kconfig.debug b/arch/loongarch/Kconfig.debug index 8d36aab53008..98d60630c3d4 100644 --- a/arch/loongarch/Kconfig.debug +++ b/arch/loongarch/Kconfig.debug @@ -26,4 +26,15 @@ config UNWINDER_PROLOGUE Some of the addresses it reports may be incorrect (but better than the Guess unwinder).

+config UNWINDER_ORC + bool "ORC unwinder" + select OBJTOOL + help + This option enables the ORC (Oops Rewind Capability) unwinder for + unwinding kernel stack traces. It uses a custom data format which is + a simplified version of the DWARF Call Frame Information standard. + + Enabling this option will increase the kernel's runtime memory usage + by roughly 2-4MB, depending on your kernel config. + endchoice diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile index d423fba7c406..f7acc9bc7ff1 100644 --- a/arch/loongarch/Makefile +++ b/arch/loongarch/Makefile @@ -25,6 +25,18 @@ endif 32bit-emul = elf32loongarch 64bit-emul = elf64loongarch

+ifdef CONFIG_UNWINDER_ORC +orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h +orc_hash_sh := $(srctree)/scripts/orc_hash.sh +targets += $(orc_hash_h) +quiet_cmd_orc_hash = GEN $@ + cmd_orc_hash = mkdir -p $(dir $@); \ + $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@ +$(orc_hash_h): $(srctree)/arch/loongarch/include/asm/orc_types.h $(orc_hash_sh) FORCE + $(call if_changed,orc_hash) +archprepare: $(orc_hash_h) +endif + ifdef CONFIG_DYNAMIC_FTRACE KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY CC_FLAGS_FTRACE := -fpatchable-function-entry=2 @@ -68,8 +80,6 @@ LDFLAGS_vmlinux += -static -n -nostdlib ifdef CONFIG_AS_HAS_EXPLICIT_RELOCS cflags-y += $(call cc-option,-mexplicit-relocs) KBUILD_CFLAGS_KERNEL += $(call cc-option,-mdirect-extern-access) -KBUILD_AFLAGS_MODULE += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno-relax) -KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno-relax) else cflags-y += $(call cc-option,-mno-explicit-relocs) KBUILD_AFLAGS_KERNEL += -Wa,-mla-global-with-pcrel @@ -78,6 +88,15 @@ KBUILD_AFLAGS_MODULE += -Wa,-mla-global-with-abs KBUILD_CFLAGS_MODULE += -fplt -Wa,-mla-global-with-abs,-mla-local-with-abs endif

+KBUILD_AFLAGS += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno-relax) +KBUILD_CFLAGS += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno-relax) +KBUILD_AFLAGS += $(call cc-option,-mthin-add-sub) $(call cc-option,-Wa$(comma)-mthin-add-sub) +KBUILD_CFLAGS += $(call cc-option,-mthin-add-sub) $(call cc-option,-Wa$(comma)-mthin-add-sub) + +ifdef CONFIG_OBJTOOL +KBUILD_CFLAGS += -fno-jump-tables +endif + ifeq ($(CONFIG_RELOCATABLE),y) KBUILD_CFLAGS_KERNEL += -fPIE LDFLAGS_vmlinux += -static -pie --no-dynamic-linker -z notext $(call ld-option, --apply-dynamic-relocs) diff --git a/arch/loongarch/include/asm/Kbuild b/arch/loongarch/include/asm/Kbuild index 27f66930ab6a..c862672ed953 100644 --- a/arch/loongarch/include/asm/Kbuild +++ b/arch/loongarch/include/asm/Kbuild @@ -1,4 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +generated-y += orc_hash.h + generic-y += dma-contiguous.h generic-y += mcs_spinlock.h generic-y += parport.h diff --git a/arch/loongarch/include/asm/bug.h b/arch/loongarch/include/asm/bug.h index d4ca3ba25418..08388876ade4 100644 --- a/arch/loongarch/include/asm/bug.h +++ b/arch/loongarch/include/asm/bug.h @@ -44,6 +44,7 @@ do { \ instrumentation_begin(); \ __BUG_FLAGS(BUGFLAG_WARNING|(flags)); \ + annotate_reachable(); \ instrumentation_end(); \ } while (0)

diff --git a/arch/loongarch/include/asm/exception.h b/arch/loongarch/include/asm/exception.h index af74a3fdcad1..c6d20736fd92 100644 --- a/arch/loongarch/include/asm/exception.h +++ b/arch/loongarch/include/asm/exception.h @@ -6,6 +6,8 @@ #include <asm/ptrace.h> #include <linux/kprobes.h>

+extern void *exception_table[]; + void show_registers(struct pt_regs *regs);

asmlinkage void cache_parity_error(void); diff --git a/arch/loongarch/include/asm/module.h b/arch/loongarch/include/asm/module.h index 2ecd82bb64e1..f33f3fd32ecc 100644 --- a/arch/loongarch/include/asm/module.h +++ b/arch/loongarch/include/asm/module.h @@ -6,6 +6,7 @@ #define _ASM_MODULE_H

#include <asm/inst.h> +#include <asm/orc_types.h> #include <asm-generic/module.h>

#define RELA_STACK_DEPTH 16 @@ -21,6 +22,12 @@ struct mod_arch_specific { struct mod_section plt; struct mod_section plt_idx;

+#ifdef CONFIG_UNWINDER_ORC + unsigned int num_orcs; + int *orc_unwind_ip; + struct orc_entry *orc_unwind; +#endif + /* For CONFIG_DYNAMIC_FTRACE */ struct plt_entry *ftrace_trampolines; }; diff --git a/arch/loongarch/include/asm/orc_header.h b/arch/loongarch/include/asm/orc_header.h new file mode 100644 index 000000000000..f9d509c3fd70 --- /dev/null +++ b/arch/loongarch/include/asm/orc_header.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#ifndef _ORC_HEADER_H +#define _ORC_HEADER_H + +#include <linux/types.h> +#include <linux/compiler.h> +#include <asm/orc_hash.h> + +/* + * The header is currently a 20-byte hash of the ORC entry definition; see + * scripts/orc_hash.sh. + */ +#define ORC_HEADER \ + __used __section(".orc_header") __aligned(4) \ + static const u8 orc_header[] = { ORC_HASH } + +#endif /* _ORC_HEADER_H */ diff --git a/arch/loongarch/include/asm/orc_lookup.h b/arch/loongarch/include/asm/orc_lookup.h new file mode 100644 index 000000000000..b02e6357def4 --- /dev/null +++ b/arch/loongarch/include/asm/orc_lookup.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _ORC_LOOKUP_H +#define _ORC_LOOKUP_H + +/* + * This is a lookup table for speeding up access to the .orc_unwind table. + * Given an input address offset, the corresponding lookup table entry + * specifies a subset of the .orc_unwind table to search. + * + * Each block represents the end of the previous range and the start of the + * next range. An extra block is added to give the last range an end. + * + * The block size should be a power of 2 to avoid a costly 'div' instruction. + * + * A block size of 256 was chosen because it roughly doubles unwinder + * performance while only adding ~5% to the ORC data footprint. + */ +#define LOOKUP_BLOCK_ORDER 8 +#define LOOKUP_BLOCK_SIZE (1 << LOOKUP_BLOCK_ORDER) + +#ifndef LINKER_SCRIPT + +extern unsigned int orc_lookup[]; +extern unsigned int orc_lookup_end[]; + +#define LOOKUP_START_IP (unsigned long)_stext +#define LOOKUP_STOP_IP (unsigned long)_etext + +#endif /* LINKER_SCRIPT */ + +#endif /* _ORC_LOOKUP_H */ diff --git a/arch/loongarch/include/asm/orc_types.h b/arch/loongarch/include/asm/orc_types.h new file mode 100644 index 000000000000..caf1f71a1057 --- /dev/null +++ b/arch/loongarch/include/asm/orc_types.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _ORC_TYPES_H +#define _ORC_TYPES_H + +#include <linux/types.h> + +/* + * The ORC_REG_* registers are base registers which are used to find other + * registers on the stack. + * + * ORC_REG_PREV_SP, also known as DWARF Call Frame Address (CFA), is the + * address of the previous frame: the caller's SP before it called the current + * function. + * + * ORC_REG_UNDEFINED means the corresponding register's value didn't change in + * the current frame. + * + * The most commonly used base registers are SP and FP -- which the previous SP + * is usually based on -- and PREV_SP and UNDEFINED -- which the previous FP is + * usually based on. + * + * The rest of the base registers are needed for special cases like entry code + * and GCC realigned stacks. + */ +#define ORC_REG_UNDEFINED 0 +#define ORC_REG_PREV_SP 1 +#define ORC_REG_SP 2 +#define ORC_REG_FP 3 +#define ORC_REG_MAX 4 + +#define ORC_TYPE_UNDEFINED 0 +#define ORC_TYPE_END_OF_STACK 1 +#define ORC_TYPE_CALL 2 +#define ORC_TYPE_REGS 3 +#define ORC_TYPE_REGS_PARTIAL 4 + +#ifndef __ASSEMBLY__ +/* + * This struct is more or less a vastly simplified version of the DWARF Call + * Frame Information standard. It contains only the necessary parts of DWARF + * CFI, simplified for ease of access by the in-kernel unwinder. It tells the + * unwinder how to find the previous SP and FP (and sometimes entry regs) on + * the stack for a given code address. Each instance of the struct corresponds + * to one or more code locations. + */ +struct orc_entry { + s16 sp_offset; + s16 fp_offset; + s16 ra_offset; + unsigned int sp_reg:4; + unsigned int fp_reg:4; + unsigned int ra_reg:4; + unsigned int type:3; + unsigned int signal:1; +}; +#endif /* __ASSEMBLY__ */ + +#endif /* _ORC_TYPES_H */ diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/include/asm/stackframe.h index 35ba862f2025..66736837085b 100644 --- a/arch/loongarch/include/asm/stackframe.h +++ b/arch/loongarch/include/asm/stackframe.h @@ -13,6 +13,7 @@ #include <asm/asm-offsets.h> #include <asm/loongarch.h> #include <asm/thread_info.h> +#include <asm/unwind_hints.h>

/* Make the addition of cfi info a little easier. */ .macro cfi_rel_offset reg offset=0 docfi=0 @@ -173,6 +174,7 @@ li.w t0, CSR_CRMD_WE csrxchg t0, t0, LOONGARCH_CSR_CRMD #endif + UNWIND_HINT_REGS .endm

.macro SAVE_ALL docfi=0 @@ -230,6 +232,7 @@

.macro RESTORE_SP_AND_RET docfi=0 cfi_ld sp, PT_R3, \docfi + UNWIND_HINT_FUNC ertn .endm

diff --git a/arch/loongarch/include/asm/unwind.h b/arch/loongarch/include/asm/unwind.h index b9dce87afd2e..40a6763c5aec 100644 --- a/arch/loongarch/include/asm/unwind.h +++ b/arch/loongarch/include/asm/unwind.h @@ -16,6 +16,7 @@ enum unwinder_type { UNWINDER_GUESS, UNWINDER_PROLOGUE, + UNWINDER_ORC, };

struct unwind_state { @@ -24,7 +25,7 @@ struct unwind_state { struct task_struct *task; bool first, error, reset; int graph_idx; - unsigned long sp, pc, ra; + unsigned long sp, fp, pc, ra; };

bool default_next_frame(struct unwind_state *state); @@ -61,14 +62,17 @@ static __always_inline void __unwind_start(struct unwind_state *state, state->sp = regs->regs[3]; state->pc = regs->csr_era; state->ra = regs->regs[1]; + state->fp = regs->regs[22]; } else if (task && task != current) { state->sp = thread_saved_fp(task); state->pc = thread_saved_ra(task); state->ra = 0; + state->fp = 0; } else { state->sp = (unsigned long)__builtin_frame_address(0); state->pc = (unsigned long)__builtin_return_address(0); state->ra = 0; + state->fp = 0; } state->task = task; get_stack_info(state->sp, state->task, &state->stack_info); @@ -77,6 +81,18 @@ static __always_inline void __unwind_start(struct unwind_state *state,

static __always_inline unsigned long __unwind_get_return_address(struct unwind_state *state) { - return unwind_done(state) ? 0 : state->pc; + if (unwind_done(state)) + return 0; + + return __kernel_text_address(state->pc) ? state->pc : 0; } + +#ifdef CONFIG_UNWINDER_ORC +void unwind_init(void); +void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, void *orc, size_t orc_size); +#else +static inline void unwind_init(void) {} +static inline void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, void *orc, size_t orc_size) {} +#endif + #endif /* _ASM_UNWIND_H */ diff --git a/arch/loongarch/include/asm/unwind_hints.h b/arch/loongarch/include/asm/unwind_hints.h new file mode 100644 index 000000000000..a01086ad9dde --- /dev/null +++ b/arch/loongarch/include/asm/unwind_hints.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_LOONGARCH_UNWIND_HINTS_H +#define _ASM_LOONGARCH_UNWIND_HINTS_H + +#include <linux/objtool.h> +#include <asm/orc_types.h> + +#ifdef __ASSEMBLY__ + +.macro UNWIND_HINT_UNDEFINED + UNWIND_HINT type=UNWIND_HINT_TYPE_UNDEFINED +.endm + +.macro UNWIND_HINT_END_OF_STACK + UNWIND_HINT type=UNWIND_HINT_TYPE_END_OF_STACK +.endm + +.macro UNWIND_HINT_REGS + UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_REGS +.endm + +.macro UNWIND_HINT_FUNC + UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_CALL +.endm + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_LOONGARCH_UNWIND_HINTS_H */ diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index 6c148ccea674..caf9a0b5e62d 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -3,6 +3,8 @@ # Makefile for the Linux/LoongArch kernel. #

+OBJECT_FILES_NON_STANDARD_head.o := y + extra-y := vmlinux.lds

obj-y += head.o cpu-probe.o cacheinfo.o env.o setup.o entry.o genex.o \ @@ -22,6 +24,7 @@ obj-$(CONFIG_ARCH_STRICT_ALIGN) += unaligned.o

CFLAGS_module.o += $(call cc-option,-Wno-override-init,) CFLAGS_syscall.o += $(call cc-option,-Wno-override-init,) +CFLAGS_traps.o += $(call cc-option,-Wno-override-init,) CFLAGS_perf_event.o += $(call cc-option,-Wno-override-init,)

ifdef CONFIG_FUNCTION_TRACER @@ -64,6 +67,7 @@ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o

obj-$(CONFIG_UNWINDER_GUESS) += unwind_guess.o obj-$(CONFIG_UNWINDER_PROLOGUE) += unwind_prologue.o +obj-$(CONFIG_UNWINDER_ORC) += unwind_orc.o

obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_regs.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index 1ec8e4c4cc2b..48e7e34e355e 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -14,11 +14,13 @@ #include <asm/regdef.h> #include <asm/stackframe.h> #include <asm/thread_info.h> +#include <asm/unwind_hints.h>

.text .cfi_sections .debug_frame .align 5 SYM_CODE_START(handle_syscall) + UNWIND_HINT_UNDEFINED csrrd t0, PERCPU_BASE_KS la.pcrel t1, kernelsp add.d t1, t1, t0 @@ -57,6 +59,7 @@ SYM_CODE_START(handle_syscall) cfi_st fp, PT_R22

SAVE_STATIC + UNWIND_HINT_REGS

#ifdef CONFIG_KGDB li.w t1, CSR_CRMD_WE @@ -75,6 +78,7 @@ SYM_CODE_END(handle_syscall) _ASM_NOKPROBE(handle_syscall)

SYM_CODE_START(ret_from_fork) + UNWIND_HINT_REGS bl schedule_tail # a0 = struct task_struct *prev move a0, sp bl syscall_exit_to_user_mode @@ -84,6 +88,7 @@ SYM_CODE_START(ret_from_fork) SYM_CODE_END(ret_from_fork)

SYM_CODE_START(ret_from_kernel_thread) + UNWIND_HINT_REGS bl schedule_tail # a0 = struct task_struct *prev move a0, s1 jirl ra, s0, 0 diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S index 4382e36ae3d4..69a85f2479fb 100644 --- a/arch/loongarch/kernel/fpu.S +++ b/arch/loongarch/kernel/fpu.S @@ -15,6 +15,7 @@ #include <asm/fpregdef.h> #include <asm/loongarch.h> #include <asm/regdef.h> +#include <asm/unwind_hints.h>

#define FPU_REG_WIDTH 8 #define LSX_REG_WIDTH 16 @@ -526,3 +527,9 @@ SYM_FUNC_END(_restore_lasx_context) .L_fpu_fault: li.w a0, -EFAULT # failure jr ra + +#ifdef CONFIG_CPU_HAS_LBT +STACK_FRAME_NON_STANDARD _restore_fp +STACK_FRAME_NON_STANDARD _restore_lsx +STACK_FRAME_NON_STANDARD _restore_lasx +#endif diff --git a/arch/loongarch/kernel/genex.S b/arch/loongarch/kernel/genex.S index 2bb3aa2dcfcb..86d5d90ebefe 100644 --- a/arch/loongarch/kernel/genex.S +++ b/arch/loongarch/kernel/genex.S @@ -32,6 +32,7 @@ SYM_FUNC_START(__arch_cpu_idle) SYM_FUNC_END(__arch_cpu_idle)

SYM_CODE_START(handle_vint) + UNWIND_HINT_UNDEFINED BACKUP_T0T1 SAVE_ALL la_abs t1, __arch_cpu_idle @@ -49,6 +50,7 @@ SYM_CODE_START(handle_vint) SYM_CODE_END(handle_vint)

SYM_CODE_START(except_vec_cex) + UNWIND_HINT_UNDEFINED b cache_parity_error SYM_CODE_END(except_vec_cex)

@@ -67,6 +69,7 @@ SYM_CODE_END(except_vec_cex) .macro BUILD_HANDLER exception handler prep .align 5 SYM_CODE_START(handle_\exception) + UNWIND_HINT_UNDEFINED 666: BACKUP_T0T1 SAVE_ALL @@ -77,7 +80,9 @@ SYM_CODE_END(except_vec_cex) 668: RESTORE_ALL_AND_RET SYM_CODE_END(handle_\exception) + .pushsection ".data", "aw", %progbits SYM_DATA(unwind_hint_\exception, .word 668b - 666b) + .popsection .endm

BUILD_HANDLER ade ade badv @@ -94,6 +99,7 @@ SYM_CODE_END(except_vec_cex) BUILD_HANDLER reserved reserved none /* others */

SYM_CODE_START(handle_sys) + UNWIND_HINT_UNDEFINED la_abs t0, handle_syscall jr t0 SYM_CODE_END(handle_sys) diff --git a/arch/loongarch/kernel/lbt.S b/arch/loongarch/kernel/lbt.S index 9c75120a26d8..001f061d226a 100644 --- a/arch/loongarch/kernel/lbt.S +++ b/arch/loongarch/kernel/lbt.S @@ -11,6 +11,7 @@ #include <asm/asm-offsets.h> #include <asm/errno.h> #include <asm/regdef.h> +#include <asm/unwind_hints.h>

#define SCR_REG_WIDTH 8

@@ -153,3 +154,5 @@ SYM_FUNC_END(_restore_ftop_context) .L_lbt_fault: li.w a0, -EFAULT # failure jr ra + +STACK_FRAME_NON_STANDARD _restore_ftop_context diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S index 482aa553aa2d..0c65cf09110c 100644 --- a/arch/loongarch/kernel/mcount_dyn.S +++ b/arch/loongarch/kernel/mcount_dyn.S @@ -73,6 +73,7 @@ SYM_FUNC_START(ftrace_stub) SYM_FUNC_END(ftrace_stub)

SYM_CODE_START(ftrace_common) + UNWIND_HINT_UNDEFINED PTR_ADDI a0, ra, -8 /* arg0: ip */ move a1, t0 /* arg1: parent_ip */ la.pcrel t1, function_trace_op @@ -113,12 +114,14 @@ ftrace_common_return: SYM_CODE_END(ftrace_common)

SYM_CODE_START(ftrace_caller) + UNWIND_HINT_UNDEFINED ftrace_regs_entry allregs=0 b ftrace_common SYM_CODE_END(ftrace_caller)

#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS SYM_CODE_START(ftrace_regs_caller) + UNWIND_HINT_UNDEFINED ftrace_regs_entry allregs=1 b ftrace_common SYM_CODE_END(ftrace_regs_caller) @@ -126,6 +129,7 @@ SYM_CODE_END(ftrace_regs_caller)

#ifdef CONFIG_FUNCTION_GRAPH_TRACER SYM_CODE_START(ftrace_graph_caller) + UNWIND_HINT_UNDEFINED PTR_L a0, sp, PT_ERA PTR_ADDI a0, a0, -8 /* arg0: self_addr */ PTR_ADDI a1, sp, PT_R1 /* arg1: parent */ @@ -134,6 +138,7 @@ SYM_CODE_START(ftrace_graph_caller) SYM_CODE_END(ftrace_graph_caller)

SYM_CODE_START(return_to_handler) + UNWIND_HINT_UNDEFINED /* Save return value regs */ PTR_ADDI sp, sp, -FGRET_REGS_SIZE PTR_S a0, sp, FGRET_REGS_A0 @@ -155,6 +160,7 @@ SYM_CODE_END(return_to_handler)

#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS SYM_CODE_START(ftrace_stub_direct_tramp) + UNWIND_HINT_UNDEFINED jr t0 SYM_CODE_END(ftrace_stub_direct_tramp) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.c index b13b2858fe39..c7d0338d12c1 100644 --- a/arch/loongarch/kernel/module.c +++ b/arch/loongarch/kernel/module.c @@ -20,6 +20,7 @@ #include <linux/kernel.h> #include <asm/alternative.h> #include <asm/inst.h> +#include <asm/unwind.h>

static int rela_stack_push(s64 stack_value, s64 *rela_stack, size_t *rela_stack_top) { @@ -515,15 +516,28 @@ static void module_init_ftrace_plt(const Elf_Ehdr *hdr, int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) { - const Elf_Shdr *s, *se; const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + const Elf_Shdr *s, *alt = NULL, *orc = NULL, *orc_ip = NULL, *ftrace = NULL;

- for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) { + for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { if (!strcmp(".altinstructions", secstrs + s->sh_name)) - apply_alternatives((void *)s->sh_addr, (void *)s->sh_addr + s->sh_size); + alt = s; + if (!strcmp(".orc_unwind", secstrs + s->sh_name)) + orc = s; + if (!strcmp(".orc_unwind_ip", secstrs + s->sh_name)) + orc_ip = s; if (!strcmp(".ftrace_trampoline", secstrs + s->sh_name)) - module_init_ftrace_plt(hdr, s, mod); + ftrace = s; }

+ if (alt) + apply_alternatives((void *)alt->sh_addr, (void *)alt->sh_addr + alt->sh_size); + + if (orc && orc_ip) + unwind_module_init(mod, (void *)orc_ip->sh_addr, orc_ip->sh_size, (void *)orc->sh_addr, orc->sh_size); + + if (ftrace) + module_init_ftrace_plt(hdr, ftrace, mod); + return 0; } diff --git a/arch/loongarch/kernel/relocate_kernel.S b/arch/loongarch/kernel/relocate_kernel.S index f49f6b053763..84e6de2fd973 100644 --- a/arch/loongarch/kernel/relocate_kernel.S +++ b/arch/loongarch/kernel/relocate_kernel.S @@ -15,6 +15,7 @@ #include <asm/addrspace.h>

SYM_CODE_START(relocate_new_kernel) + UNWIND_HINT_UNDEFINED /* * a0: EFI boot flag for the new kernel * a1: Command line pointer for the new kernel @@ -90,6 +91,7 @@ SYM_CODE_END(relocate_new_kernel) * then start at the entry point from LOONGARCH_IOCSR_MBUF0. */ SYM_CODE_START(kexec_smp_wait) + UNWIND_HINT_UNDEFINED 1: li.w t0, 0x100 /* wait for init loop */ 2: addi.w t0, t0, -1 /* limit mailbox access */ bnez t0, 2b @@ -106,6 +108,5 @@ SYM_CODE_END(kexec_smp_wait)

relocate_new_kernel_end:

-SYM_DATA_START(relocate_new_kernel_size) - PTR relocate_new_kernel_end - relocate_new_kernel -SYM_DATA_END(relocate_new_kernel_size) + .section ".data" +SYM_DATA(relocate_new_kernel_size, .long relocate_new_kernel_end - relocate_new_kernel) diff --git a/arch/loongarch/kernel/rethook_trampoline.S b/arch/loongarch/kernel/rethook_trampoline.S index bd5772c96338..d4ceb2fa2a5c 100644 --- a/arch/loongarch/kernel/rethook_trampoline.S +++ b/arch/loongarch/kernel/rethook_trampoline.S @@ -76,6 +76,7 @@ .endm

SYM_CODE_START(arch_rethook_trampoline) + UNWIND_HINT_UNDEFINED addi.d sp, sp, -PT_SIZE save_all_base_regs

diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c index a210e2507368..2577ce5a3dde 100644 --- a/arch/loongarch/kernel/setup.c +++ b/arch/loongarch/kernel/setup.c @@ -48,6 +48,7 @@ #include <asm/sections.h> #include <asm/setup.h> #include <asm/time.h> +#include <asm/unwind.h> #include "legacy_boot.h"

#define SMBIOS_BIOSSIZE_OFFSET 0x09 @@ -646,6 +647,7 @@ static void __init prefill_possible_map(void) void __init setup_arch(char **cmdline_p) { cpu_probe(); + unwind_init();

init_environ(); efi_init(); diff --git a/arch/loongarch/kernel/stacktrace.c b/arch/loongarch/kernel/stacktrace.c index f623feb2129f..eaec82e02c92 100644 --- a/arch/loongarch/kernel/stacktrace.c +++ b/arch/loongarch/kernel/stacktrace.c @@ -29,6 +29,7 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, regs->csr_era = thread_saved_ra(task); } regs->regs[1] = 0; + regs->regs[22] = 0; }

for (unwind_start(&state, task, regs); diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index aebfc3733a76..f9f4eb00c92e 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -53,6 +53,32 @@

#include "access-helper.h"

+void *exception_table[EXCCODE_INT_START] = { + [0 ... EXCCODE_INT_START - 1] = handle_reserved, + + [EXCCODE_TLBI] = handle_tlb_load, + [EXCCODE_TLBL] = handle_tlb_load, + [EXCCODE_TLBS] = handle_tlb_store, + [EXCCODE_TLBM] = handle_tlb_modify, + [EXCCODE_TLBNR] = handle_tlb_protect, + [EXCCODE_TLBNX] = handle_tlb_protect, + [EXCCODE_TLBPE] = handle_tlb_protect, + [EXCCODE_ADE] = handle_ade, + [EXCCODE_ALE] = handle_ale, + [EXCCODE_BCE] = handle_bce, + [EXCCODE_SYS] = handle_sys, + [EXCCODE_BP] = handle_bp, + [EXCCODE_INE] = handle_ri, + [EXCCODE_IPE] = handle_ri, + [EXCCODE_FPDIS] = handle_fpu, + [EXCCODE_LSXDIS] = handle_lsx, + [EXCCODE_LASXDIS] = handle_lasx, + [EXCCODE_FPE] = handle_fpe, + [EXCCODE_WATCH] = handle_watch, + [EXCCODE_BTDIS] = handle_lbt, +}; +EXPORT_SYMBOL_GPL(exception_table); + static void show_backtrace(struct task_struct *task, const struct pt_regs *regs, const char *loglvl, bool user) { @@ -1150,19 +1176,9 @@ void __init trap_init(void) for (i = EXCCODE_INT_START; i <= EXCCODE_INT_END; i++) set_handler(i * VECSIZE, handle_vint, VECSIZE);

- set_handler(EXCCODE_ADE * VECSIZE, handle_ade, VECSIZE); - set_handler(EXCCODE_ALE * VECSIZE, handle_ale, VECSIZE); - set_handler(EXCCODE_BCE * VECSIZE, handle_bce, VECSIZE); - set_handler(EXCCODE_SYS * VECSIZE, handle_sys, VECSIZE); - set_handler(EXCCODE_BP * VECSIZE, handle_bp, VECSIZE); - set_handler(EXCCODE_INE * VECSIZE, handle_ri, VECSIZE); - set_handler(EXCCODE_IPE * VECSIZE, handle_ri, VECSIZE); - set_handler(EXCCODE_FPDIS * VECSIZE, handle_fpu, VECSIZE); - set_handler(EXCCODE_LSXDIS * VECSIZE, handle_lsx, VECSIZE); - set_handler(EXCCODE_LASXDIS * VECSIZE, handle_lasx, VECSIZE); - set_handler(EXCCODE_FPE * VECSIZE, handle_fpe, VECSIZE); - set_handler(EXCCODE_BTDIS * VECSIZE, handle_lbt, VECSIZE); - set_handler(EXCCODE_WATCH * VECSIZE, handle_watch, VECSIZE); + /* Set exception vector handler */ + for (i = EXCCODE_ADE; i <= EXCCODE_BTDIS; i++) + set_handler(i * VECSIZE, exception_table[i], VECSIZE);

cache_error_setup();

diff --git a/arch/loongarch/kernel/unwind_orc.c b/arch/loongarch/kernel/unwind_orc.c new file mode 100644 index 000000000000..b25722876331 --- /dev/null +++ b/arch/loongarch/kernel/unwind_orc.c @@ -0,0 +1,528 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/objtool.h> +#include <linux/module.h> +#include <linux/sort.h> +#include <asm/exception.h> +#include <asm/orc_header.h> +#include <asm/orc_lookup.h> +#include <asm/orc_types.h> +#include <asm/ptrace.h> +#include <asm/setup.h> +#include <asm/stacktrace.h> +#include <asm/tlb.h> +#include <asm/unwind.h> + +ORC_HEADER; + +#define orc_warn(fmt, ...) \ + printk_deferred_once(KERN_WARNING "WARNING: " fmt, ##__VA_ARGS__) + +extern int __start_orc_unwind_ip[]; +extern int __stop_orc_unwind_ip[]; +extern struct orc_entry __start_orc_unwind[]; +extern struct orc_entry __stop_orc_unwind[]; + +static bool orc_init __ro_after_init; +static unsigned int lookup_num_blocks __ro_after_init; + +/* Fake frame pointer entry -- used as a fallback for generated code */ +static struct orc_entry orc_fp_entry = { + .sp_reg = ORC_REG_FP, + .sp_offset = 16, + .fp_reg = ORC_REG_PREV_SP, + .fp_offset = -16, + .ra_reg = ORC_REG_PREV_SP, + .ra_offset = -8, + .type = ORC_TYPE_CALL +}; + +/* + * If we crash with IP==0, the last successfully executed instruction + * was probably an indirect function call with a NULL function pointer, + * and we don't have unwind information for NULL. + * This hardcoded ORC entry for IP==0 allows us to unwind from a NULL function + * pointer into its parent and then continue normally from there. + */ +static struct orc_entry orc_null_entry = { + .sp_reg = ORC_REG_SP, + .sp_offset = sizeof(long), + .fp_reg = ORC_REG_UNDEFINED, + .type = ORC_TYPE_CALL +}; + +static inline unsigned long orc_ip(const int *ip) +{ + return (unsigned long)ip + *ip; +} + +static struct orc_entry *__orc_find(int *ip_table, struct orc_entry *u_table, + unsigned int num_entries, unsigned long ip) +{ + int *first = ip_table; + int *mid = first, *found = first; + int *last = ip_table + num_entries - 1; + + if (!num_entries) + return NULL; + + /* + * Do a binary range search to find the rightmost duplicate of a given + * starting address. Some entries are section terminators which are + * "weak" entries for ensuring there are no gaps. They should be + * ignored when they conflict with a real entry. + */ + while (first <= last) { + mid = first + ((last - first) / 2); + + if (orc_ip(mid) <= ip) { + found = mid; + first = mid + 1; + } else + last = mid - 1; + } + + return u_table + (found - ip_table); +} + +#ifdef CONFIG_MODULES +static struct orc_entry *orc_module_find(unsigned long ip) +{ + struct module *mod; + + mod = __module_address(ip); + if (!mod || !mod->arch.orc_unwind || !mod->arch.orc_unwind_ip) + return NULL; + + return __orc_find(mod->arch.orc_unwind_ip, mod->arch.orc_unwind, mod->arch.num_orcs, ip); +} +#else +static struct orc_entry *orc_module_find(unsigned long ip) +{ + return NULL; +} +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE +static struct orc_entry *orc_find(unsigned long ip); + +/* + * Ftrace dynamic trampolines do not have orc entries of their own. + * But they are copies of the ftrace entries that are static and + * defined in ftrace_*.S, which do have orc entries. + * + * If the unwinder comes across a ftrace trampoline, then find the + * ftrace function that was used to create it, and use that ftrace + * function's orc entry, as the placement of the return code in + * the stack will be identical. + */ +static struct orc_entry *orc_ftrace_find(unsigned long ip) +{ + struct ftrace_ops *ops; + unsigned long tramp_addr, offset; + + ops = ftrace_ops_trampoline(ip); + if (!ops) + return NULL; + + /* Set tramp_addr to the start of the code copied by the trampoline */ + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) + tramp_addr = (unsigned long)ftrace_regs_caller; + else + tramp_addr = (unsigned long)ftrace_caller; + + /* Now place tramp_addr to the location within the trampoline ip is at */ + offset = ip - ops->trampoline; + tramp_addr += offset; + + /* Prevent unlikely recursion */ + if (ip == tramp_addr) + return NULL; + + return orc_find(tramp_addr); +} +#else +static struct orc_entry *orc_ftrace_find(unsigned long ip) +{ + return NULL; +} +#endif + +static struct orc_entry *orc_find(unsigned long ip) +{ + static struct orc_entry *orc; + + if (ip == 0) + return &orc_null_entry; + + /* For non-init vmlinux addresses, use the fast lookup table: */ + if (ip >= LOOKUP_START_IP && ip < LOOKUP_STOP_IP) { + unsigned int idx, start, stop; + + idx = (ip - LOOKUP_START_IP) / LOOKUP_BLOCK_SIZE; + + if (unlikely((idx >= lookup_num_blocks-1))) { + orc_warn("WARNING: bad lookup idx: idx=%u num=%u ip=%pB\n", + idx, lookup_num_blocks, (void *)ip); + return NULL; + } + + start = orc_lookup[idx]; + stop = orc_lookup[idx + 1] + 1; + + if (unlikely((__start_orc_unwind + start >= __stop_orc_unwind) || + (__start_orc_unwind + stop > __stop_orc_unwind))) { + orc_warn("WARNING: bad lookup value: idx=%u num=%u start=%u stop=%u ip=%pB\n", + idx, lookup_num_blocks, start, stop, (void *)ip); + return NULL; + } + + return __orc_find(__start_orc_unwind_ip + start, + __start_orc_unwind + start, stop - start, ip); + } + + /* vmlinux .init slow lookup: */ + if (is_kernel_inittext(ip)) + return __orc_find(__start_orc_unwind_ip, __start_orc_unwind, + __stop_orc_unwind_ip - __start_orc_unwind_ip, ip); + + /* Module lookup: */ + orc = orc_module_find(ip); + if (orc) + return orc; + + return orc_ftrace_find(ip); +} + +#ifdef CONFIG_MODULES + +static DEFINE_MUTEX(sort_mutex); +static int *cur_orc_ip_table = __start_orc_unwind_ip; +static struct orc_entry *cur_orc_table = __start_orc_unwind; + +static void orc_sort_swap(void *_a, void *_b, int size) +{ + int delta = _b - _a; + int *a = _a, *b = _b, tmp; + struct orc_entry *orc_a, *orc_b; + + /* Swap the .orc_unwind_ip entries: */ + tmp = *a; + *a = *b + delta; + *b = tmp - delta; + + /* Swap the corresponding .orc_unwind entries: */ + orc_a = cur_orc_table + (a - cur_orc_ip_table); + orc_b = cur_orc_table + (b - cur_orc_ip_table); + swap(*orc_a, *orc_b); +} + +static int orc_sort_cmp(const void *_a, const void *_b) +{ + const int *a = _a, *b = _b; + unsigned long a_val = orc_ip(a); + unsigned long b_val = orc_ip(b); + struct orc_entry *orc_a; + + if (a_val > b_val) + return 1; + if (a_val < b_val) + return -1; + + /* + * The "weak" section terminator entries need to always be first + * to ensure the lookup code skips them in favor of real entries. + * These terminator entries exist to handle any gaps created by + * whitelisted .o files which didn't get objtool generation. + */ + orc_a = cur_orc_table + (a - cur_orc_ip_table); + + return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1; +} + +void unwind_module_init(struct module *mod, void *_orc_ip, size_t orc_ip_size, + void *_orc, size_t orc_size) +{ + int *orc_ip = _orc_ip; + struct orc_entry *orc = _orc; + unsigned int num_entries = orc_ip_size / sizeof(int); + + WARN_ON_ONCE(orc_ip_size % sizeof(int) != 0 || + orc_size % sizeof(*orc) != 0 || + num_entries != orc_size / sizeof(*orc)); + + /* + * The 'cur_orc_*' globals allow the orc_sort_swap() callback to + * associate an .orc_unwind_ip table entry with its corresponding + * .orc_unwind entry so they can both be swapped. + */ + mutex_lock(&sort_mutex); + cur_orc_ip_table = orc_ip; + cur_orc_table = orc; + sort(orc_ip, num_entries, sizeof(int), orc_sort_cmp, orc_sort_swap); + mutex_unlock(&sort_mutex); + + mod->arch.orc_unwind_ip = orc_ip; + mod->arch.orc_unwind = orc; + mod->arch.num_orcs = num_entries; +} +#endif + +void __init unwind_init(void) +{ + int i; + size_t orc_size = (void *)__stop_orc_unwind - (void *)__start_orc_unwind; + size_t orc_ip_size = (void *)__stop_orc_unwind_ip - (void *)__start_orc_unwind_ip; + size_t num_entries = orc_ip_size / sizeof(int); + struct orc_entry *orc; + + if (!num_entries || orc_ip_size % sizeof(int) != 0 || + orc_size % sizeof(struct orc_entry) != 0 || + num_entries != orc_size / sizeof(struct orc_entry)) { + orc_warn("WARNING: Bad or missing .orc_unwind table. Disabling unwinder.\n"); + return; + } + + /* + * Note, the orc_unwind and orc_unwind_ip tables were already + * sorted at build time via the 'sorttable' tool. + * It's ready for binary search straight away, no need to sort it. + */ + + /* Initialize the fast lookup table: */ + lookup_num_blocks = orc_lookup_end - orc_lookup; + for (i = 0; i < lookup_num_blocks-1; i++) { + orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind, + num_entries, LOOKUP_START_IP + (LOOKUP_BLOCK_SIZE * i)); + if (!orc) { + orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n"); + return; + } + + orc_lookup[i] = orc - __start_orc_unwind; + } + + /* Initialize the ending block: */ + orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind, num_entries, LOOKUP_STOP_IP); + if (!orc) { + orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n"); + return; + } + orc_lookup[lookup_num_blocks-1] = orc - __start_orc_unwind; + + orc_init = true; +} + +static inline bool on_stack(struct stack_info *info, unsigned long addr, size_t len) +{ + unsigned long begin = info->begin; + unsigned long end = info->end; + + return (info->type != STACK_TYPE_UNKNOWN && + addr >= begin && addr < end && addr + len > begin && addr + len <= end); +} + +static bool stack_access_ok(struct unwind_state *state, unsigned long addr, size_t len) +{ + struct stack_info *info = &state->stack_info; + + if (on_stack(info, addr, len)) + return true; + + return !get_stack_info(addr, state->task, info) && on_stack(info, addr, len); +} + +unsigned long unwind_get_return_address(struct unwind_state *state) +{ + return __unwind_get_return_address(state); +} +EXPORT_SYMBOL_GPL(unwind_get_return_address); + +void unwind_start(struct unwind_state *state, struct task_struct *task, + struct pt_regs *regs) +{ + __unwind_start(state, task, regs); + state->type = UNWINDER_ORC; + if (!unwind_done(state) && !__kernel_text_address(state->pc)) + unwind_next_frame(state); +} +EXPORT_SYMBOL_GPL(unwind_start); + +static bool is_entry_func(unsigned long addr) +{ + extern u32 kernel_entry; + extern u32 kernel_entry_end; + + return addr >= (unsigned long)&kernel_entry && addr < (unsigned long)&kernel_entry_end; +} + +static inline unsigned long bt_address(unsigned long ra) +{ + extern unsigned long eentry; + + if (__kernel_text_address(ra)) + return ra; + + if (__module_text_address(ra)) + return ra; + + if (ra >= eentry && ra < eentry + EXCCODE_INT_END * VECSIZE) { + unsigned long func; + unsigned long type = (ra - eentry) / VECSIZE; + unsigned long offset = (ra - eentry) % VECSIZE; + + switch (type) { + case 0 ... EXCCODE_INT_START - 1: + func = (unsigned long)exception_table[type]; + break; + case EXCCODE_INT_START ... EXCCODE_INT_END: + func = (unsigned long)handle_vint; + break; + default: + func = (unsigned long)handle_reserved; + break; + } + + return func + offset; + } + + return ra; +} + +bool unwind_next_frame(struct unwind_state *state) +{ + unsigned long *p, pc; + struct pt_regs *regs; + struct orc_entry *orc; + struct stack_info *info = &state->stack_info; + + if (unwind_done(state)) + return false; + + /* Don't let modules unload while we're reading their ORC data. */ + preempt_disable(); + + if (is_entry_func(state->pc)) + goto end; + + orc = orc_find(state->pc); + if (!orc) { + /* + * As a fallback, try to assume this code uses a frame pointer. + * This is useful for generated code, like BPF, which ORC + * doesn't know about. This is just a guess, so the rest of + * the unwind is no longer considered reliable. + */ + orc = &orc_fp_entry; + state->error = true; + } else { + if (orc->type == ORC_TYPE_UNDEFINED) + goto err; + + if (orc->type == ORC_TYPE_END_OF_STACK) + goto end; + } + + switch (orc->sp_reg) { + case ORC_REG_SP: + if (info->type == STACK_TYPE_IRQ && state->sp == info->end) + orc->type = ORC_TYPE_REGS; + else + state->sp = state->sp + orc->sp_offset; + break; + case ORC_REG_FP: + state->sp = state->fp; + break; + default: + orc_warn("unknown SP base reg %d at %pB\n", orc->sp_reg, (void *)state->pc); + goto err; + } + + switch (orc->fp_reg) { + case ORC_REG_PREV_SP: + p = (unsigned long *)(state->sp + orc->fp_offset); + if (!stack_access_ok(state, (unsigned long)p, sizeof(unsigned long))) + goto err; + + state->fp = *p; + break; + case ORC_REG_UNDEFINED: + /* Nothing. */ + break; + default: + orc_warn("unknown FP base reg %d at %pB\n", orc->fp_reg, (void *)state->pc); + goto err; + } + + switch (orc->type) { + case ORC_TYPE_CALL: + if (orc->ra_reg == ORC_REG_PREV_SP) { + p = (unsigned long *)(state->sp + orc->ra_offset); + if (!stack_access_ok(state, (unsigned long)p, sizeof(unsigned long))) + goto err; + + pc = unwind_graph_addr(state, *p, state->sp); + pc -= LOONGARCH_INSN_SIZE; + } else if (orc->ra_reg == ORC_REG_UNDEFINED) { + if (!state->ra || state->ra == state->pc) + goto err; + + pc = unwind_graph_addr(state, state->ra, state->sp); + pc -= LOONGARCH_INSN_SIZE; + state->ra = 0; + } else { + orc_warn("unknown ra base reg %d at %pB\n", orc->ra_reg, (void *)state->pc); + goto err; + } + break; + case ORC_TYPE_REGS: + if (info->type == STACK_TYPE_IRQ && state->sp == info->end) + regs = (struct pt_regs *)info->next_sp; + else + regs = (struct pt_regs *)state->sp; + + if (!stack_access_ok(state, (unsigned long)regs, sizeof(*regs))) + goto err; + + if ((info->end == (unsigned long)regs + sizeof(*regs)) && + !regs->regs[3] && !regs->regs[1]) + goto end; + + if (user_mode(regs)) + goto end; + + pc = regs->csr_era; + if (!__kernel_text_address(pc)) + goto err; + + state->sp = regs->regs[3]; + state->ra = regs->regs[1]; + state->fp = regs->regs[22]; + get_stack_info(state->sp, state->task, info); + + break; + default: + orc_warn("unknown .orc_unwind entry type %d at %pB\n", orc->type, (void *)state->pc); + goto err; + } + + state->pc = bt_address(pc); + if (!state->pc) { + pr_err("cannot find unwind pc at %pK\n", (void *)pc); + goto err; + } + + if (!__kernel_text_address(state->pc)) + goto err; + + preempt_enable(); + return true; + +err: + state->error = true; + +end: + preempt_enable(); + state->stack_info.type = STACK_TYPE_UNKNOWN; + return false; +} +EXPORT_SYMBOL_GPL(unwind_next_frame); diff --git a/arch/loongarch/kernel/vmlinux.lds.S b/arch/loongarch/kernel/vmlinux.lds.S index d5afd0c80a49..3c7595342730 100644 --- a/arch/loongarch/kernel/vmlinux.lds.S +++ b/arch/loongarch/kernel/vmlinux.lds.S @@ -2,6 +2,7 @@ #include <linux/sizes.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> +#include <asm/orc_lookup.h>

#define PAGE_SIZE _PAGE_SIZE #define RO_EXCEPTION_TABLE_ALIGN 4 @@ -123,6 +124,8 @@ SECTIONS } #endif

+ ORC_UNWIND_TABLE + .sdata : { *(.sdata) } diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S index ba976509bfe8..1fcc4b7eda32 100644 --- a/arch/loongarch/kvm/switch.S +++ b/arch/loongarch/kvm/switch.S @@ -8,7 +8,7 @@ #include <asm/asmmacro.h> #include <asm/loongarch.h> #include <asm/regdef.h> -#include <asm/stackframe.h> +#include <asm/unwind_hints.h>

#define HGPR_OFFSET(x) (PT_R0 + 8*x) #define GGPR_OFFSET(x) (KVM_ARCH_GGPR + 8*x) @@ -112,6 +112,7 @@ .text .cfi_sections .debug_frame SYM_CODE_START(kvm_exc_entry) + UNWIND_HINT_UNDEFINED csrwr a2, KVM_TEMP_KS csrrd a2, KVM_VCPU_KS addi.d a2, a2, KVM_VCPU_ARCH @@ -279,3 +280,9 @@ SYM_FUNC_END(kvm_restore_lasx) .section ".rodata" SYM_DATA(kvm_exception_size, .quad kvm_exc_entry_end - kvm_exc_entry) SYM_DATA(kvm_enter_guest_size, .quad kvm_enter_guest_end - kvm_enter_guest) + +#ifdef CONFIG_CPU_HAS_LBT +STACK_FRAME_NON_STANDARD kvm_restore_fpu +STACK_FRAME_NON_STANDARD kvm_restore_lsx +STACK_FRAME_NON_STANDARD kvm_restore_lasx +#endif diff --git a/arch/loongarch/lib/clear_user.S b/arch/loongarch/lib/clear_user.S index be741544e62b..7a0db643b286 100644 --- a/arch/loongarch/lib/clear_user.S +++ b/arch/loongarch/lib/clear_user.S @@ -10,6 +10,7 @@ #include <asm/asm-extable.h> #include <asm/cpu.h> #include <asm/regdef.h> +#include <asm/unwind_hints.h>

SYM_FUNC_START(__clear_user) /* @@ -204,3 +205,5 @@ SYM_FUNC_START(__clear_user_fast) _asm_extable 28b, .Lsmall_fixup _asm_extable 29b, .Lexit SYM_FUNC_END(__clear_user_fast) + +STACK_FRAME_NON_STANDARD __clear_user_fast diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S index feec3d362803..095ce9181c6c 100644 --- a/arch/loongarch/lib/copy_user.S +++ b/arch/loongarch/lib/copy_user.S @@ -10,6 +10,7 @@ #include <asm/asm-extable.h> #include <asm/cpu.h> #include <asm/regdef.h> +#include <asm/unwind_hints.h>

SYM_FUNC_START(__copy_user) /* @@ -278,3 +279,5 @@ SYM_FUNC_START(__copy_user_fast) _asm_extable 58b, .Lexit _asm_extable 59b, .Lexit SYM_FUNC_END(__copy_user_fast) + +STACK_FRAME_NON_STANDARD __copy_user_fast diff --git a/arch/loongarch/lib/memcpy.S b/arch/loongarch/lib/memcpy.S index fa1148878d2b..9517a2f961af 100644 --- a/arch/loongarch/lib/memcpy.S +++ b/arch/loongarch/lib/memcpy.S @@ -9,6 +9,7 @@ #include <asm/asmmacro.h> #include <asm/cpu.h> #include <asm/regdef.h> +#include <asm/unwind_hints.h>

.section .noinstr.text, "ax"

@@ -197,3 +198,5 @@ SYM_FUNC_START(__memcpy_fast) jr ra SYM_FUNC_END(__memcpy_fast) _ASM_NOKPROBE(__memcpy_fast) + +STACK_FRAME_NON_STANDARD __memcpy_small diff --git a/arch/loongarch/lib/memset.S b/arch/loongarch/lib/memset.S index 06d3ca54cbfe..df3846620553 100644 --- a/arch/loongarch/lib/memset.S +++ b/arch/loongarch/lib/memset.S @@ -9,6 +9,7 @@ #include <asm/asmmacro.h> #include <asm/cpu.h> #include <asm/regdef.h> +#include <asm/unwind_hints.h>

.macro fill_to_64 r0 bstrins.d \r0, \r0, 15, 8 @@ -166,3 +167,5 @@ SYM_FUNC_START(__memset_fast) jr ra SYM_FUNC_END(__memset_fast) _ASM_NOKPROBE(__memset_fast) + +STACK_FRAME_NON_STANDARD __memset_fast diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c index 56bf1dd5358a..5fcda8adf90d 100644 --- a/arch/loongarch/mm/tlb.c +++ b/arch/loongarch/mm/tlb.c @@ -9,8 +9,9 @@ #include <linux/hugetlb.h> #include <linux/export.h>

-#include <asm/cpu.h> #include <asm/bootinfo.h> +#include <asm/cpu.h> +#include <asm/exception.h> #include <asm/mmu_context.h> #include <asm/pgtable.h> #include <asm/tlb.h> @@ -266,24 +267,20 @@ static void setup_tlb_handler(int cpu) setup_ptwalker(); local_flush_tlb_all();

+ if (cpu_has_ptw) { + exception_table[EXCCODE_TLBI] = handle_tlb_load_ptw; + exception_table[EXCCODE_TLBL] = handle_tlb_load_ptw; + exception_table[EXCCODE_TLBS] = handle_tlb_store_ptw; + exception_table[EXCCODE_TLBM] = handle_tlb_modify_ptw; + } + /* The tlb handlers are generated only once */ if (cpu == 0) { memcpy((void *)tlbrentry, handle_tlb_refill, 0x80); local_flush_icache_range(tlbrentry, tlbrentry + 0x80); - if (!cpu_has_ptw) { - set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE); - set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load, VECSIZE); - set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store, VECSIZE); - set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify, VECSIZE); - } else { - set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load_ptw, VECSIZE); - set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load_ptw, VECSIZE); - set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store_ptw, VECSIZE); - set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify_ptw, VECSIZE); - } - set_handler(EXCCODE_TLBNR * VECSIZE, handle_tlb_protect, VECSIZE); - set_handler(EXCCODE_TLBNX * VECSIZE, handle_tlb_protect, VECSIZE); - set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE); + + for (int i = EXCCODE_TLBL; i <= EXCCODE_TLBPE; i++) + set_handler(i * VECSIZE, exception_table[i], VECSIZE); } else { int vec_sz __maybe_unused; void *addr __maybe_unused; diff --git a/arch/loongarch/mm/tlbex.S b/arch/loongarch/mm/tlbex.S index d5d682f3d29f..a44387b838af 100644 --- a/arch/loongarch/mm/tlbex.S +++ b/arch/loongarch/mm/tlbex.S @@ -18,6 +18,7 @@

.macro tlb_do_page_fault, write SYM_CODE_START(tlb_do_page_fault_\write) + UNWIND_HINT_UNDEFINED SAVE_ALL csrrd a2, LOONGARCH_CSR_BADV move a0, sp @@ -32,6 +33,7 @@ tlb_do_page_fault 1

SYM_CODE_START(handle_tlb_protect) + UNWIND_HINT_UNDEFINED BACKUP_T0T1 SAVE_ALL move a0, sp @@ -44,6 +46,7 @@ SYM_CODE_START(handle_tlb_protect) SYM_CODE_END(handle_tlb_protect)

SYM_CODE_START(handle_tlb_load) + UNWIND_HINT_UNDEFINED csrwr t0, EXCEPTION_KS0 csrwr t1, EXCEPTION_KS1 csrwr ra, EXCEPTION_KS2 @@ -190,6 +193,7 @@ nopage_tlb_load: SYM_CODE_END(handle_tlb_load)

SYM_CODE_START(handle_tlb_load_ptw) + UNWIND_HINT_UNDEFINED csrwr t0, LOONGARCH_CSR_KS0 csrwr t1, LOONGARCH_CSR_KS1 la_abs t0, tlb_do_page_fault_0 @@ -197,6 +201,7 @@ SYM_CODE_START(handle_tlb_load_ptw) SYM_CODE_END(handle_tlb_load_ptw)

SYM_CODE_START(handle_tlb_store) + UNWIND_HINT_UNDEFINED csrwr t0, EXCEPTION_KS0 csrwr t1, EXCEPTION_KS1 csrwr ra, EXCEPTION_KS2 @@ -346,6 +351,7 @@ nopage_tlb_store: SYM_CODE_END(handle_tlb_store)

SYM_CODE_START(handle_tlb_store_ptw) + UNWIND_HINT_UNDEFINED csrwr t0, LOONGARCH_CSR_KS0 csrwr t1, LOONGARCH_CSR_KS1 la_abs t0, tlb_do_page_fault_1 @@ -353,6 +359,7 @@ SYM_CODE_START(handle_tlb_store_ptw) SYM_CODE_END(handle_tlb_store_ptw)

SYM_CODE_START(handle_tlb_modify) + UNWIND_HINT_UNDEFINED csrwr t0, EXCEPTION_KS0 csrwr t1, EXCEPTION_KS1 csrwr ra, EXCEPTION_KS2 @@ -500,6 +507,7 @@ nopage_tlb_modify: SYM_CODE_END(handle_tlb_modify)

SYM_CODE_START(handle_tlb_modify_ptw) + UNWIND_HINT_UNDEFINED csrwr t0, LOONGARCH_CSR_KS0 csrwr t1, LOONGARCH_CSR_KS1 la_abs t0, tlb_do_page_fault_1 @@ -507,6 +515,7 @@ SYM_CODE_START(handle_tlb_modify_ptw) SYM_CODE_END(handle_tlb_modify_ptw)

SYM_CODE_START(handle_tlb_refill) + UNWIND_HINT_UNDEFINED csrwr t0, LOONGARCH_CSR_TLBRSAVE csrrd t0, LOONGARCH_CSR_PGD lddir t0, t0, 3 diff --git a/arch/loongarch/vdso/Makefile b/arch/loongarch/vdso/Makefile index 549bf247303a..a17dcbead97f 100644 --- a/arch/loongarch/vdso/Makefile +++ b/arch/loongarch/vdso/Makefile @@ -4,6 +4,7 @@ KASAN_SANITIZE := n UBSAN_SANITIZE := n KCOV_INSTRUMENT := n +OBJECT_FILES_NON_STANDARD := y

# Include the generic Makefile to check the built vdso. include $(srctree)/lib/vdso/Makefile diff --git a/include/linux/compiler.h b/include/linux/compiler.h index d7779a18b24f..df29ddb3c862 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -116,6 +116,14 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, */ #define __stringify_label(n) #n

+#define __annotate_reachable(c) ({ \ + asm volatile(__stringify_label(c) ":\n\t" \ + ".pushsection .discard.reachable\n\t" \ + ".long " __stringify_label(c) "b - .\n\t" \ + ".popsection\n\t"); \ +}) +#define annotate_reachable() __annotate_reachable(__COUNTER__) + #define __annotate_unreachable(c) ({ \ asm volatile(__stringify_label(c) ":\n\t" \ ".pushsection .discard.unreachable\n\t" \ @@ -128,6 +136,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #define __annotate_jump_table __section(".rodata..c_jump_table")

#else /* !CONFIG_OBJTOOL */ +#define annotate_reachable() #define annotate_unreachable() #define __annotate_jump_table #endif /* CONFIG_OBJTOOL */ diff --git a/scripts/Makefile b/scripts/Makefile index 576cf64be667..e4cca53d2285 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -31,9 +31,12 @@ HOSTLDLIBS_sign-file = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null |

ifdef CONFIG_UNWINDER_ORC ifeq ($(ARCH),x86_64) -ARCH := x86 +SRCARCH := x86 endif -HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/include +ifeq ($(ARCH),loongarch) +SRCARCH := loongarch +endif +HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/$(SRCARCH)/include HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED endif

From: Jinyang He hejinyang@loongson.cn

mainline inclusion from mainline-v6.9 commit 199cc14cb4f1cb8668be45f67af41755ed5f0175 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

---------------------------------------------------------------------------

The arch-specified function ftrace_regs_set_instruction_pointer() has been implemented in arch/loongarch/include/asm/ftrace.h, so here only implement arch_stack_walk_reliable() function.

Here are the test logs:

[root@linux fedora]# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3

[root@linux fedora]# modprobe livepatch-sample [root@linux fedora]# cat /proc/cmdline this has been live patched

[root@linux fedora]# echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled [root@linux fedora]# rmmod livepatch_sample [root@linux fedora]# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3

[root@linux fedora]# dmesg -t | tail -5 livepatch: enabling patch 'livepatch_sample' livepatch: 'livepatch_sample': starting patching transition livepatch: 'livepatch_sample': patching complete livepatch: 'livepatch_sample': starting unpatching transition livepatch: 'livepatch_sample': unpatching complete

Signed-off-by: Jinyang He hejinyang@loongson.cn [select HAVE_LIVEPATCH_FTRACE to enable LIVEPATCH - yangtiezhu] [add empty asm/livepatch.h to avoid building errors - yangtiezhu] Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/loongarch/Kconfig | 5 +++ arch/loongarch/include/asm/livepatch.h | 15 +++++++++ arch/loongarch/include/asm/thread_info.h | 2 ++ arch/loongarch/kernel/stacktrace.c | 40 ++++++++++++++++++++++++ 4 files changed, 62 insertions(+) create mode 100644 arch/loongarch/include/asm/livepatch.h

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 24880542a1e8..d66cb26bd3a7 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -135,6 +135,8 @@ config LOONGARCH select HAVE_KPROBES_ON_FTRACE select HAVE_KRETPROBES select HAVE_KVM + select HAVE_LIVEPATCH + select HAVE_LIVEPATCH_FTRACE select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS @@ -143,6 +145,7 @@ config LOONGARCH select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API + select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC select HAVE_RETHOOK select HAVE_RSEQ select HAVE_SAMPLE_FTRACE_DIRECT @@ -623,6 +626,8 @@ config RANDOMIZE_BASE_MAX_OFFSET

This is limited by the size of the lower address memory, 256MB.

+source "kernel/livepatch/Kconfig" + endmenu

config ARCH_SELECT_MEMORY_MODEL diff --git a/arch/loongarch/include/asm/livepatch.h b/arch/loongarch/include/asm/livepatch.h new file mode 100644 index 000000000000..d1740f2fae25 --- /dev/null +++ b/arch/loongarch/include/asm/livepatch.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * livepatch.h - LoongArch-specific Kernel Live Patching Core + * + * Copyright (C) 2024 Loongson Technology Corporation Limited + */ + +#ifndef _ASM_LOONGARCH_LIVEPATCH_H +#define _ASM_LOONGARCH_LIVEPATCH_H + +#ifdef CONFIG_LIVEPATCH_WO_FTRACE + +#endif /* CONFIG_LIVEPATCH_WO_FTRACE */ + +#endif /* _ASM_LOONGARCH_LIVEPATCH_H */ diff --git a/arch/loongarch/include/asm/thread_info.h b/arch/loongarch/include/asm/thread_info.h index 8cb653d49a54..8bf0e6f51546 100644 --- a/arch/loongarch/include/asm/thread_info.h +++ b/arch/loongarch/include/asm/thread_info.h @@ -86,6 +86,7 @@ register unsigned long current_stack_pointer __asm__("$sp"); #define TIF_LASX_CTX_LIVE 18 /* LASX context must be preserved */ #define TIF_USEDLBT 19 /* LBT was used by this task this quantum (SMP) */ #define TIF_LBT_CTX_LIVE 20 /* LBT context must be preserved */ +#define TIF_PATCH_PENDING 21 /* pending live patching update */

#define _TIF_SIGPENDING (1<<TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) @@ -105,6 +106,7 @@ register unsigned long current_stack_pointer __asm__("$sp"); #define _TIF_LASX_CTX_LIVE (1<<TIF_LASX_CTX_LIVE) #define _TIF_USEDLBT (1<<TIF_USEDLBT) #define _TIF_LBT_CTX_LIVE (1<<TIF_LBT_CTX_LIVE) +#define _TIF_PATCH_PENDING (1<<TIF_PATCH_PENDING)

#endif /* __KERNEL__ */ #endif /* _ASM_THREAD_INFO_H */ diff --git a/arch/loongarch/kernel/stacktrace.c b/arch/loongarch/kernel/stacktrace.c index eaec82e02c92..9a038d1070d7 100644 --- a/arch/loongarch/kernel/stacktrace.c +++ b/arch/loongarch/kernel/stacktrace.c @@ -40,6 +40,46 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, } }

+int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, + void *cookie, struct task_struct *task) +{ + unsigned long addr; + struct pt_regs dummyregs; + struct pt_regs *regs = &dummyregs; + struct unwind_state state; + + if (task == current) { + regs->regs[3] = (unsigned long)__builtin_frame_address(0); + regs->csr_era = (unsigned long)__builtin_return_address(0); + } else { + regs->regs[3] = thread_saved_fp(task); + regs->csr_era = thread_saved_ra(task); + } + regs->regs[1] = 0; + regs->regs[22] = 0; + + for (unwind_start(&state, task, regs); + !unwind_done(&state) && !unwind_error(&state); unwind_next_frame(&state)) { + addr = unwind_get_return_address(&state); + + /* + * A NULL or invalid return address probably means there's some + * generated code which __kernel_text_address() doesn't know about. + */ + if (!addr) + return -EINVAL; + + if (!consume_entry(cookie, addr)) + return -EINVAL; + } + + /* Check for stack corruption */ + if (unwind_error(&state)) + return -EINVAL; + + return 0; +} + static int copy_stack_frame(unsigned long fp, struct stack_frame *frame) {

mainline inclusion from mainline-v6.11 commit 80376323e2b6a4559f86b2b4d864848ac25cb054 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

---------------------------------------------------------------------------

There exist some warnings when building kernel if CONFIG_CPU_HAS_LBT is set but CONFIG_CPU_HAS_LSX and CONFIG_CPU_HAS_LASX are not set. In this case, there are no definitions of _restore_lsx & _restore_lasx and there are also no definitions of kvm_restore_lsx & kvm_restore_lasx in fpu.S and switch.S respectively, just add some ifdefs to fix these warnings.

AS arch/loongarch/kernel/fpu.o arch/loongarch/kernel/fpu.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0 arch/loongarch/kernel/fpu.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0

AS [M] arch/loongarch/kvm/switch.o arch/loongarch/kvm/switch.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0 arch/loongarch/kvm/switch.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0

MODPOST Module.symvers ERROR: modpost: "kvm_restore_lsx" [arch/loongarch/kvm/kvm.ko] undefined! ERROR: modpost: "kvm_restore_lasx" [arch/loongarch/kvm/kvm.ko] undefined!

Cc: stable@vger.kernel.org # 6.9+ Fixes: cb8a2ef0848c ("LoongArch: Add ORC stack unwinder support") Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202408120955.qls5oNQY-lkp@intel.com/ Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/loongarch/kernel/fpu.S | 4 ++++ arch/loongarch/kvm/switch.S | 4 ++++ 2 files changed, 8 insertions(+)

diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S index 69a85f2479fb..6ab640101457 100644 --- a/arch/loongarch/kernel/fpu.S +++ b/arch/loongarch/kernel/fpu.S @@ -530,6 +530,10 @@ SYM_FUNC_END(_restore_lasx_context)

#ifdef CONFIG_CPU_HAS_LBT STACK_FRAME_NON_STANDARD _restore_fp +#ifdef CONFIG_CPU_HAS_LSX STACK_FRAME_NON_STANDARD _restore_lsx +#endif +#ifdef CONFIG_CPU_HAS_LASX STACK_FRAME_NON_STANDARD _restore_lasx #endif +#endif diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S index 1fcc4b7eda32..ab4082d40bb3 100644 --- a/arch/loongarch/kvm/switch.S +++ b/arch/loongarch/kvm/switch.S @@ -283,6 +283,10 @@ SYM_DATA(kvm_enter_guest_size, .quad kvm_enter_guest_end - kvm_enter_guest)

#ifdef CONFIG_CPU_HAS_LBT STACK_FRAME_NON_STANDARD kvm_restore_fpu +#ifdef CONFIG_CPU_HAS_LSX STACK_FRAME_NON_STANDARD kvm_restore_lsx +#endif +#ifdef CONFIG_CPU_HAS_LASX STACK_FRAME_NON_STANDARD kvm_restore_lasx #endif +#endif

mainline inclusion from mainline-v6.12-rc1 commit b8468bd92ae19939d4844899fa05147888732519 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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For now, it can enable objtool for Clang, just remove !CC_IS_CLANG for HAVE_OBJTOOL in arch/loongarch/Kconfig.

Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/loongarch/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index e628c78b0ca8..695f584c4595 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -139,7 +139,7 @@ config LOONGARCH select HAVE_LIVEPATCH_FTRACE select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI - select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB && !CC_IS_CLANG + select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB select HAVE_PCI select HAVE_PERF_EVENTS select HAVE_PERF_REGS

mainline inclusion from mainline-v6.11 commit c5b1184decc819756ae549ba54c63b6790c4ddfd category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB3IRE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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Currently, there is an assembler message when generating kernel/bpf/core.o under CONFIG_OBJTOOL with LoongArch compiler toolchain:

Warning: setting incorrect section attributes for .rodata..c_jump_table

This is because the section ".rodata..c_jump_table" should be readonly, but there is a "W" (writable) part of the flags:

$ readelf -S kernel/bpf/core.o | grep -A 1 "rodata..c" [34] .rodata..c_j[...] PROGBITS 0000000000000000 0000d2e0 0000000000000800 0000000000000000 WA 0 0 8

There is no above issue on x86 due to the generated section flag is only "A" (allocatable). In order to silence the warning on LoongArch, specify the attribute like ".rodata..c_jump_table,"a",@progbits #" explicitly, then the section attribute of ".rodata..c_jump_table" must be readonly in the kernel/bpf/core.o file.

Before:

$ objdump -h kernel/bpf/core.o | grep -A 1 "rodata..c" 21 .rodata..c_jump_table 00000800 0000000000000000 0000000000000000 0000d2e0 2**3 CONTENTS, ALLOC, LOAD, RELOC, DATA

After:

$ objdump -h kernel/bpf/core.o | grep -A 1 "rodata..c" 21 .rodata..c_jump_table 00000800 0000000000000000 0000000000000000 0000d2e0 2**3 CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA

By the way, AFAICT, maybe the root cause is related with the different compiler behavior of various archs, so to some extent this change is a workaround for LoongArch, and also there is no effect for x86 which is the only port supported by objtool before LoongArch with this patch.

Link: https://lkml.kernel.org/r/20240924062710.1243-1-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn Cc: Josh Poimboeuf jpoimboe@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: stable@vger.kernel.org [6.9+] Signed-off-by: Andrew Morton akpm@linux-foundation.org --- include/linux/compiler.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/compiler.h b/include/linux/compiler.h index df29ddb3c862..266a74943831 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -133,7 +133,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #define annotate_unreachable() __annotate_unreachable(__COUNTER__)

/* Annotate a C jump table to allow objtool to follow the code flow */ -#define __annotate_jump_table __section(".rodata..c_jump_table") +#define __annotate_jump_table __section(".rodata..c_jump_table,"a",@progbits #")

#else /* !CONFIG_OBJTOOL */ #define annotate_reachable()