github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-23 05:04:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

arm64: syscall: Pass 'orig_x0' as first argument to native system call

Browse Source 
syscall_get_arguments() returns 'regs->orig_x0' for the first system
call argument so as to avoid aliasing with the syscall return value in
'regs->regs[0]' on the return path, however the actual syscall
invocation passes 'regs->regs[0]' as the first parameter.

Although the two registers should be kept in sync during syscall entry
for native tasks, pass 'regs->orig_x0' as the first syscall parameter
for consistency with the syscall argument APIs. Compat tasks continue to
use 'regs->regs[0]' for compatibility with the behaviour of the 32-bit
kernel.

Suggested-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Will Deacon 2026-07-30 14:26:51 +01:00
parent 88b839ce49
commit 5a87e8c7f3
1 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/arm64/include/asm/syscall_wrapper.h
View File

@ -10,13 +10,13 @@
#include <asm/ptrace.h>
#define SC_ARM64_REGS_TO_ARGS(x, ...) \
#ifdef CONFIG_COMPAT
#define COMPAT_SC_ARM64_REGS_TO_ARGS(x, ...) \
__MAP(x,__SC_ARGS \
,,regs->regs[0],,regs->regs[1],,regs->regs[2] \
,,regs->regs[3],,regs->regs[4],,regs->regs[5])
#ifdef CONFIG_COMPAT
#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
asmlinkage long __arm64_compat_sys##name(const struct pt_regs *regs); \
ALLOW_ERROR_INJECTION(__arm64_compat_sys##name, ERRNO); \
@ -24,7 +24,7 @@
static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
asmlinkage long __arm64_compat_sys##name(const struct pt_regs *regs) \
{ \
return __se_compat_sys##name(SC_ARM64_REGS_TO_ARGS(x,__VA_ARGS__)); \
return __se_compat_sys##name(COMPAT_SC_ARM64_REGS_TO_ARGS(x,__VA_ARGS__)); \
} \
static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
{ \
@ -46,6 +46,11 @@
#endif /* CONFIG_COMPAT */
#define SC_ARM64_REGS_TO_ARGS(x, ...) \
__MAP(x,__SC_ARGS \
,,regs->orig_x0,,regs->regs[1],,regs->regs[2] \
,,regs->regs[3],,regs->regs[4],,regs->regs[5])
#define __SYSCALL_DEFINEx(x, name, ...) \
asmlinkage long __arm64_sys##name(const struct pt_regs *regs); \
ALLOW_ERROR_INJECTION(__arm64_sys##name, ERRNO); \