hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5GB28 CVE: NA
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A new type of extable is added, which is specially used fixup for machine check safe. In order to keep kabi consistency, we cannot add type and data members to struct exception_table_entry(d6e2cc564775 arm64: extable: add `type` and `data` fields), so we put the fixup entry to new extable separately.
Signed-off-by: Tong Tiangen tongtiangen@huawei.com --- arch/arm64/Kconfig | 3 +++ arch/arm64/include/asm/assembler.h | 15 ++++++++++++ arch/arm64/include/asm/uaccess.h | 10 ++++++++ include/asm-generic/vmlinux.lds.h | 19 ++++++++++++++- include/linux/extable.h | 6 +++++ include/linux/module.h | 11 +++++++++ kernel/extable.c | 29 +++++++++++++++++++++++ kernel/module.c | 38 ++++++++++++++++++++++++++++++ scripts/sorttable.h | 29 +++++++++++++++++++++++ 9 files changed, 159 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 94ca5de3d1d5..4264f4185c3b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1170,6 +1170,9 @@ config ARCH_LLC_128_LINE_SIZE config ARCH_HAS_FILTER_PGPROT def_bool y
+config ARCH_HAS_MC_EXTABLE + bool + config ARCH_ENABLE_SPLIT_PMD_PTLOCK def_bool y if PGTABLE_LEVELS > 2
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index ef5e60d6d577..a84a579cf210 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -145,6 +145,21 @@ alternative_endif .popsection .endm
+/* + * Emit an entry into the machine check exception table + */ +#ifdef CONFIG_ARCH_HAS_MC_EXTABLE + .macro _asm_mc_extable, from, to + .pushsection __mc_ex_table, "a" + .align 3 + .long (\from - .), (\to - .) + .popsection + .endm +#else + .macro _asm_mc_extable, from, to + .endm +#endif + #define USER(l, x...) \ 9999: x; \ _asm_extable 9999b, l diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index abb31aa1f8ca..90e851a3f623 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -75,6 +75,16 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si " .long (" #from " - .), (" #to " - .)\n" \ " .popsection\n"
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE +#define _ASM_MC_EXTABLE(from, to) \ + " .pushsection __mc_ex_table, "a"\n" \ + " .align 3\n" \ + " .long (" #from " - .), (" #to " - .)\n" \ + " .popsection\n" +#else +#define _ASM_MC_EXTABLE(from, to) +#endif + /* * User access enabling/disabling. */ diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 274692c8b105..90c1884928e1 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -76,7 +76,9 @@ * alignment. */ #ifdef RO_EXCEPTION_TABLE_ALIGN -#define RO_EXCEPTION_TABLE EXCEPTION_TABLE(RO_EXCEPTION_TABLE_ALIGN) +#define RO_EXCEPTION_TABLE \ + EXCEPTION_TABLE(RO_EXCEPTION_TABLE_ALIGN) \ + MC_EXCEPTION_TABLE(RO_EXCEPTION_TABLE_ALIGN) #else #define RO_EXCEPTION_TABLE #endif @@ -675,6 +677,21 @@ __stop___ex_table = .; \ }
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE +/* + * Machine Check Exception table + */ +#define MC_EXCEPTION_TABLE(align) \ + . = ALIGN(align); \ + __mc_ex_table : AT(ADDR(__mc_ex_table) - LOAD_OFFSET) { \ + __start___mc_ex_table = .; \ + KEEP(*(__mc_ex_table)) \ + __stop___mc_ex_table = .; \ + } +#else +#define MC_EXCEPTION_TABLE(align) +#endif + /* * .BTF */ diff --git a/include/linux/extable.h b/include/linux/extable.h index 4ab9e78f313b..a5cdffabe89d 100644 --- a/include/linux/extable.h +++ b/include/linux/extable.h @@ -19,12 +19,18 @@ void trim_init_extable(struct module *m);
/* Given an address, look for it in the exception tables */ const struct exception_table_entry *search_exception_tables(unsigned long add); +#ifdef CONFIG_ARCH_HAS_MC_EXTABLE +const struct exception_table_entry *search_mc_exception_tables(unsigned long add); +#endif const struct exception_table_entry * search_kernel_exception_table(unsigned long addr);
#ifdef CONFIG_MODULES /* For extable.c to search modules' exception tables. */ const struct exception_table_entry *search_module_extables(unsigned long addr); +#ifdef CONFIG_ARCH_HAS_MC_EXTABLE +const struct exception_table_entry *search_module_mc_extables(unsigned long addr); +#endif #else static inline const struct exception_table_entry * search_module_extables(unsigned long addr) diff --git a/include/linux/module.h b/include/linux/module.h index 54cdd20fc3de..b2b2c742a397 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -429,6 +429,11 @@ struct module { /* Startup function. */ int (*init)(void);
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE + /* there is 8-byte hole on all platforms */ + KABI_FILL_HOLE(unsigned int num_mc_exentries) +#endif + /* Core layout: rbtree is accessed frequently, so keep together. */ struct module_layout core_layout __module_layout_align; struct module_layout init_layout; @@ -553,7 +558,13 @@ struct module { struct error_injection_entry *ei_funcs; unsigned int num_ei_funcs; #endif + +#ifdef CONFIG_ARCH_HAS_MC_EXTABLE + KABI_USE(1, struct exception_table_entry *mc_extable) +#else KABI_RESERVE(1) +#endif + KABI_RESERVE(2) KABI_RESERVE(3) KABI_RESERVE(4) diff --git a/kernel/extable.c b/kernel/extable.c index b0ea5eb0c3b4..0ebc05fd72fd 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -28,6 +28,11 @@ DEFINE_MUTEX(text_mutex); extern struct exception_table_entry __start___ex_table[]; extern struct exception_table_entry __stop___ex_table[];
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE +extern struct exception_table_entry __start___mc_ex_table[]; +extern struct exception_table_entry __stop___mc_ex_table[]; +#endif + /* Cleared by build time tools if the table is already sorted. */ u32 __initdata __visible main_extable_sort_needed = 1;
@@ -39,6 +44,14 @@ void __init sort_main_extable(void) pr_notice("Sorting __ex_table...\n"); sort_extable(__start___ex_table, __stop___ex_table); } + +#ifdef CONFIG_ARCH_HAS_MC_EXTABLE + if (main_extable_sort_needed && + &__stop___mc_ex_table > &__start___mc_ex_table) { + pr_notice("Sorting __mc_ex_table...\n"); + sort_extable(__start___mc_ex_table, __stop___mc_ex_table); + } +#endif }
/* Given an address, look for it in the kernel exception table */ @@ -62,6 +75,22 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr) return e; }
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE +/* Given an address, look for it in the machine check exception table */ +const +struct exception_table_entry *search_mc_exception_tables(unsigned long addr) +{ + const struct exception_table_entry *e; + + e = search_extable(__start___mc_ex_table, + __stop___mc_ex_table - __start___mc_ex_table, addr); + if (!e) + e = search_module_mc_extables(addr); + + return e; +} +#endif + int init_kernel_text(unsigned long addr) { if (addr >= (unsigned long)_sinittext && diff --git a/kernel/module.c b/kernel/module.c index febdbf2d337e..a469c7489771 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3423,6 +3423,11 @@ static int find_module_sections(struct module *mod, struct load_info *info) mod->extable = section_objs(info, "__ex_table", sizeof(*mod->extable), &mod->num_exentries);
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE + mod->mc_extable = section_objs(info, "__mc_ex_table", + sizeof(*mod->mc_extable), &mod->num_mc_exentries); +#endif + if (section_addr(info, "__obsparm")) pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
@@ -3660,6 +3665,10 @@ static int post_relocation(struct module *mod, const struct load_info *info) /* Sort exception table now relocations are done. */ sort_extable(mod->extable, mod->extable + mod->num_exentries);
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE + sort_extable(mod->mc_extable, mod->mc_extable + mod->num_mc_exentries); +#endif + /* Copy relocated percpu area over. */ percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, info->sechdrs[info->index.pcpu].sh_size); @@ -4631,6 +4640,35 @@ const struct exception_table_entry *search_module_extables(unsigned long addr) return e; }
+#ifdef CONFIG_ARCH_HAS_MC_EXTABLE +/* Given an address, look for it in the module machine check safe exception tables. */ +const struct exception_table_entry *search_module_mc_extables(unsigned long addr) +{ + const struct exception_table_entry *e = NULL; + struct module *mod; + + preempt_disable(); + mod = __module_address(addr); + if (!mod) + goto out; + + if (!mod->num_exentries) + goto out; + + e = search_extable(mod->mc_extable, + mod->num_mc_exentries, + addr); +out: + preempt_enable(); + + /* + * Now, if we found one, we are running inside it now, hence + * we cannot unload the module, hence no refcnt needed. + */ + return e; +} +#endif + /* * is_module_address - is this address inside a module? * @addr: the address to check. diff --git a/scripts/sorttable.h b/scripts/sorttable.h index a2baa2fefb13..874cbd7046b0 100644 --- a/scripts/sorttable.h +++ b/scripts/sorttable.h @@ -223,6 +223,12 @@ static int do_sort(Elf_Ehdr *ehdr, unsigned int orc_num_entries = 0; #endif
+ Elf_Shdr *mc_extab_sec = NULL; + Elf_Rel *mc_relocs = NULL; + int mc_relocs_size = 0; + char *mc_extab_image = NULL; + int mc_extab_index = 0; + shstrndx = r2(&ehdr->e_shstrndx); if (shstrndx == SHN_XINDEX) shstrndx = r(&shdr[0].sh_link); @@ -238,6 +244,12 @@ static int do_sort(Elf_Ehdr *ehdr, extab_sec = s; extab_index = i; } + + if (!strcmp(secstrings + idx, "__mc_ex_table")) { + mc_extab_sec = s; + mc_extab_index = i; + } + if (!strcmp(secstrings + idx, ".symtab")) symtab_sec = s; if (!strcmp(secstrings + idx, ".strtab")) @@ -249,6 +261,14 @@ static int do_sort(Elf_Ehdr *ehdr, relocs = (void *)ehdr + _r(&s->sh_offset); relocs_size = _r(&s->sh_size); } + + if ((r(&s->sh_type) == SHT_REL || + r(&s->sh_type) == SHT_RELA) && + r(&s->sh_info) == mc_extab_index) { + mc_relocs = (void *)ehdr + _r(&s->sh_offset); + mc_relocs_size = _r(&s->sh_size); + } + if (r(&s->sh_type) == SHT_SYMTAB_SHNDX) symtab_shndx = (Elf32_Word *)((const char *)ehdr + _r(&s->sh_offset)); @@ -310,12 +330,18 @@ static int do_sort(Elf_Ehdr *ehdr, }
extab_image = (void *)ehdr + _r(&extab_sec->sh_offset); + + if (mc_extab_sec) + mc_extab_image = (void *)ehdr + _r(&mc_extab_sec->sh_offset); + strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset); symtab = (const Elf_Sym *)((const char *)ehdr + _r(&symtab_sec->sh_offset));
if (custom_sort) { custom_sort(extab_image, _r(&extab_sec->sh_size)); + if (mc_extab_image) + custom_sort(mc_extab_image, _r(&mc_extab_sec->sh_size)); } else { int num_entries = _r(&extab_sec->sh_size) / extable_ent_size; qsort(extab_image, num_entries, @@ -326,6 +352,9 @@ static int do_sort(Elf_Ehdr *ehdr, if (relocs) memset(relocs, 0, relocs_size);
+ if (mc_relocs) + memset(mc_relocs, 0, mc_relocs_size); + /* find the flag main_extable_sort_needed */ for (sym = (void *)ehdr + _r(&symtab_sec->sh_offset); sym < sym + _r(&symtab_sec->sh_size) / sizeof(Elf_Sym);