From: Yury Norov ynorov@caviumnetworks.com
maillist inclusion category: feature bugzilla: 46790 CVE: NA
Reference: https://github.com/norov/linux/commits/ilp32-5.2
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Depending on the personality of the task, syscalls has to be dispatched to either aarch64, aarch32 or aarch64/ilp32 syscall handlers. We add the support of ILP32 mode in this series, therefore introduce corresponding syscall table.
Some system calls are wired to aarch32 syscall handlers, as listed in arch/arm64/kernel/sys_ilp32.c.
For aarch64/ilp32, top halves of syscall arguments are meaningless anthough not zeroed by hardware. Do that in the delouse_pt_regs() routine to avoid passing garbage by userspace.
Signed-off-by: Yury Norov ynorov@caviumnetworks.com Signed-off-by: Yury Norov ynorov@marvell.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com
Conflicts: arch/arm64/include/asm/unistd.h arch/arm64/include/uapi/asm/unistd.h arch/arm64/kernel/Makefile arch/arm64/kernel/syscall.c
Signed-off-by: Chen Jiahao chenjiahao16@huawei.com --- arch/arm64/include/asm/syscall.h | 4 ++ arch/arm64/include/asm/unistd.h | 7 ++- arch/arm64/include/uapi/asm/unistd.h | 15 +++++- arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/sys_ilp32.c | 76 ++++++++++++++++++++++++++++ arch/arm64/kernel/syscall.c | 25 ++++++++- 6 files changed, 125 insertions(+), 4 deletions(-) create mode 100644 arch/arm64/kernel/sys_ilp32.c
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h index 376382651199..eafd1302b237 100644 --- a/arch/arm64/include/asm/syscall.h +++ b/arch/arm64/include/asm/syscall.h @@ -17,6 +17,10 @@ extern const syscall_fn_t sys_call_table[]; extern const syscall_fn_t a32_sys_call_table[]; #endif
+#ifdef CONFIG_ARM64_ILP32 +extern const syscall_fn_t ilp32_sys_call_table[]; +#endif + static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 9dcffe4cfe23..42bd70997ac6 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -2,9 +2,14 @@ /* * Copyright (C) 2012 ARM Ltd. */ -#ifdef CONFIG_AARCH32_EL0 + +#ifdef CONFIG_COMPAT #define __ARCH_WANT_COMPAT_STAT #define __ARCH_WANT_COMPAT_STAT64 +#define __ARCH_WANT_SYS_LLSEEK +#endif + +#ifdef CONFIG_AARCH32_EL0 #define __ARCH_WANT_SYS_GETHOSTNAME #define __ARCH_WANT_SYS_PAUSE #define __ARCH_WANT_SYS_GETPGRP diff --git a/arch/arm64/include/uapi/asm/unistd.h b/arch/arm64/include/uapi/asm/unistd.h index ce2ee8f1e361..079139c04b14 100644 --- a/arch/arm64/include/uapi/asm/unistd.h +++ b/arch/arm64/include/uapi/asm/unistd.h @@ -15,9 +15,22 @@ * along with this program. If not, see http://www.gnu.org/licenses/. */
+/* + * AARCH32 interface for ILP32 syscalls. + */ +#if defined(__ILP32__) || defined(__SYSCALL_COMPAT) +#define __ARCH_WANT_SYNC_FILE_RANGE2 +#endif + +/* + * AARCH64/ILP32 is introduced after the following syscalls were deprecated. + */ +#if !(defined(__ILP32__) || defined(__SYSCALL_COMPAT)) #define __ARCH_WANT_RENAMEAT -#define __ARCH_WANT_NEW_STAT #define __ARCH_WANT_SET_GET_RLIMIT +#endif + +#define __ARCH_WANT_NEW_STAT #define __ARCH_WANT_TIME32_SYSCALLS #define __ARCH_WANT_SYS_CLONE3 #define __ARCH_WANT_MEMFD_SECRET diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 661f50308f55..3c0673bfe03e 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -41,7 +41,7 @@ obj-$(CONFIG_AARCH32_EL0) += binfmt_elf32.o sys32.o signal32.o \ obj-$(CONFIG_AARCH32_EL0) += sigreturn32.o obj-$(CONFIG_COMPAT_ALIGNMENT_FIXUPS) += compat_alignment.o obj-$(CONFIG_KUSER_HELPERS) += kuser32.o -obj-$(CONFIG_ARM64_ILP32) += binfmt_ilp32.o +obj-$(CONFIG_ARM64_ILP32) += binfmt_ilp32.o sys_ilp32.o obj-$(CONFIG_COMPAT) += sys32_common.o obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o obj-$(CONFIG_MODULES) += module.o diff --git a/arch/arm64/kernel/sys_ilp32.c b/arch/arm64/kernel/sys_ilp32.c new file mode 100644 index 000000000000..05eca957a18d --- /dev/null +++ b/arch/arm64/kernel/sys_ilp32.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * AArch64- ILP32 specific system calls implementation + * Copyright (C) 2018 Marvell. + */ + +#define __SYSCALL_COMPAT + +#include <linux/compat.h> +#include <linux/compiler.h> +#include <linux/syscalls.h> + +#include <asm/syscall.h> + +/* + * AARCH32 requires 4-page alignment for shared memory, + * but AARCH64 - only 1 page. This is the only difference + * between compat and native sys_shmat(). So ILP32 just pick + * AARCH64 version. + */ +#define __arm64_compat_sys_shmat __arm64_sys_shmat + +/* + * ILP32 needs special handling for some ptrace requests. + */ +#define __arm64_sys_ptrace __arm64_compat_sys_ptrace + +/* + * Using AARCH32 interface for syscalls that take 64-bit + * parameters in registers. + */ +#define __arm64_compat_sys_fadvise64_64 __arm64_compat_sys_aarch32_fadvise64_64 +#define __arm64_compat_sys_fallocate __arm64_compat_sys_aarch32_fallocate +#define __arm64_compat_sys_ftruncate64 __arm64_compat_sys_aarch32_ftruncate64 +#define __arm64_compat_sys_pread64 __arm64_compat_sys_aarch32_pread64 +#define __arm64_compat_sys_pwrite64 __arm64_compat_sys_aarch32_pwrite64 +#define __arm64_compat_sys_readahead __arm64_compat_sys_aarch32_readahead +#define __arm64_compat_sys_sync_file_range2 __arm64_compat_sys_aarch32_sync_file_range2 +#define __arm64_compat_sys_truncate64 __arm64_compat_sys_aarch32_truncate64 +#define __arm64_sys_mmap2 __arm64_compat_sys_aarch32_mmap2 + +/* + * Using AARCH32 interface for syscalls that take the size of + * struct statfs as an argument, as it's calculated differently + * in kernel and user spaces. + */ +#define __arm64_compat_sys_fstatfs64 __arm64_compat_sys_aarch32_fstatfs64 +#define __arm64_compat_sys_statfs64 __arm64_compat_sys_aarch32_statfs64 + +/* + * Using old interface for IPC syscalls that should handle IPC_64 flag. + */ +#define __arm64_compat_sys_semctl __arm64_compat_sys_old_semctl +#define __arm64_compat_sys_msgctl __arm64_compat_sys_old_msgctl +#define __arm64_compat_sys_shmctl __arm64_compat_sys_old_shmctl + +/* + * Wrappers to pass the pt_regs argument. + */ +#define sys_personality sys_arm64_personality + +asmlinkage long sys_ni_syscall(const struct pt_regs *); +#define __arm64_sys_ni_syscall sys_ni_syscall + +#undef __SYSCALL +#define __SYSCALL(nr, sym) asmlinkage long __arm64_##sym(const struct pt_regs *); +#include <asm/unistd.h> + +#undef __SYSCALL +#define __SYSCALL(nr, sym) [nr] = (syscall_fn_t)__arm64_##sym, + +const syscall_fn_t ilp32_sys_call_table[__NR_syscalls] = { + [0 ... __NR_syscalls - 1] = __arm64_sys_ni_syscall, +#include <asm/unistd.h> +}; diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index 75a833efd846..c5b40a43865e 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -187,10 +187,33 @@ static inline void fp_user_discard(void) } }
+#ifdef CONFIG_ARM64_ILP32 +static inline void delouse_pt_regs(struct pt_regs *regs) +{ + regs->regs[0] &= UINT_MAX; + regs->regs[1] &= UINT_MAX; + regs->regs[2] &= UINT_MAX; + regs->regs[3] &= UINT_MAX; + regs->regs[4] &= UINT_MAX; + regs->regs[5] &= UINT_MAX; + regs->regs[6] &= UINT_MAX; + regs->regs[7] &= UINT_MAX; +} +#endif + void do_el0_svc(struct pt_regs *regs) { + const syscall_fn_t *t = sys_call_table; + +#ifdef CONFIG_ARM64_ILP32 + if (is_ilp32_compat_task()) { + t = ilp32_sys_call_table; + delouse_pt_regs(regs); + } +#endif + fp_user_discard(); - el0_svc_common(regs, regs->regs[8], __NR_syscalls, sys_call_table); + el0_svc_common(regs, regs->regs[8], __NR_syscalls, t); }
#ifdef CONFIG_AARCH32_EL0