From: Jiri Olsa olsajiri@gmail.com
commit 9440c42941606af4c379afa3cf8624f0dc43a629 upstream.
With just the forward declaration of the 'struct pt_regs' in syscall_wrapper.h, the syscall stub functions:
__[x64|ia32]_sys_*(struct pt_regs *regs)
will have different definition of 'regs' argument in BTF data based on which object file they are defined in.
If the syscall's object includes 'struct pt_regs' definition, the BTF argument data will point to a 'struct pt_regs' record, like:
[226] STRUCT 'pt_regs' size=168 vlen=21 'r15' type_id=1 bits_offset=0 'r14' type_id=1 bits_offset=64 'r13' type_id=1 bits_offset=128 ...
If not, it will point to a fwd declaration record:
[15439] FWD 'pt_regs' fwd_kind=struct
and make bpf tracing program hooking on those functions unable to access fields from 'struct pt_regs'.
Include asm/ptrace.h directly in syscall_wrapper.h to make sure all syscalls see 'struct pt_regs' definition. This then results in BTF for '__*_sys_*(struct pt_regs *regs)' functions to point to the actual struct, not just the forward declaration.
[ bp: No Fixes tag as this is not really a bug fix but "adjustment" so that BTF is happy. ]
Reported-by: Akihiro HARAI jharai0815@gmail.com Signed-off-by: Jiri Olsa jolsa@kernel.org Signed-off-by: Borislav Petkov bp@suse.de Acked-by: Andrii Nakryiko andrii@kernel.org Cc: stable@vger.kernel.org # this is needed only for BTF so kernels >= 5.15 Link: https://lore.kernel.org/r/20221018122708.823792-1-jolsa@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/include/asm/syscall_wrapper.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h index 59358d1bf880..fd2669b1cb2d 100644 --- a/arch/x86/include/asm/syscall_wrapper.h +++ b/arch/x86/include/asm/syscall_wrapper.h @@ -6,7 +6,7 @@ #ifndef _ASM_X86_SYSCALL_WRAPPER_H #define _ASM_X86_SYSCALL_WRAPPER_H
-struct pt_regs; +#include <asm/ptrace.h>
extern long __x64_sys_ni_syscall(const struct pt_regs *regs); extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);