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syscalls/x86: Fix function types in COND_SYSCALL

commit 6e4847640c upstream.

Define a weak function in COND_SYSCALL instead of a weak alias to
sys_ni_syscall(), which has an incompatible type. This fixes indirect
call mismatches with Control-Flow Integrity (CFI) checking.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191008224049.115427-6-samitolvanen@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Sami Tolvanen 2019-10-08 15:40:49 -07:00 committed by Greg Kroah-Hartman
parent 3ebcb6145a
commit 499960fcb8
1 changed files with 16 additions and 5 deletions

View File

@ -6,6 +6,8 @@
#ifndef _ASM_X86_SYSCALL_WRAPPER_H
#define _ASM_X86_SYSCALL_WRAPPER_H
struct pt_regs;
/* Mapping of registers to parameters for syscalls on x86-64 and x32 */
#define SC_X86_64_REGS_TO_ARGS(x, ...) \
__MAP(x,__SC_ARGS \
@ -64,9 +66,15 @@
SYSCALL_ALIAS(__ia32_sys_##sname, __x64_sys_##sname); \
asmlinkage long __x64_sys_##sname(const struct pt_regs *__unused)
#define COND_SYSCALL(name) \
cond_syscall(__x64_sys_##name); \
cond_syscall(__ia32_sys_##name)
#define COND_SYSCALL(name) \
asmlinkage __weak long __x64_sys_##name(const struct pt_regs *__unused) \
{ \
return sys_ni_syscall(); \
} \
asmlinkage __weak long __ia32_sys_##name(const struct pt_regs *__unused)\
{ \
return sys_ni_syscall(); \
}
#define SYS_NI(name) \
SYSCALL_ALIAS(__x64_sys_##name, sys_ni_posix_timers); \
@ -218,7 +226,11 @@
#endif
#ifndef COND_SYSCALL
#define COND_SYSCALL(name) cond_syscall(__x64_sys_##name)
#define COND_SYSCALL(name) \
asmlinkage __weak long __x64_sys_##name(const struct pt_regs *__unused) \
{ \
return sys_ni_syscall(); \
}
#endif
#ifndef SYS_NI
@ -230,7 +242,6 @@
* For VSYSCALLS, we need to declare these three syscalls with the new
* pt_regs-based calling convention for in-kernel use.
*/
struct pt_regs;
asmlinkage long __x64_sys_getcpu(const struct pt_regs *regs);
asmlinkage long __x64_sys_gettimeofday(const struct pt_regs *regs);
asmlinkage long __x64_sys_time(const struct pt_regs *regs);