9440c42941
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