diff options
| author | Michael Ellerman <mpe@ellerman.id.au> | 2015-07-23 20:21:04 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-07-29 11:56:12 +1000 |
| commit | 1b1a3702a65c1a6511e4c95ecb3770dfdf235bcf (patch) | |
| tree | e5f34faf6e7ee84bdea7d4d4aca7cf49d6605941 | |
| parent | 2923e6d503465e97a378d37a588e4e6987009bc7 (diff) | |
powerpc: Don't negate error in syscall_set_return_value()
Currently the only caller of syscall_set_return_value() is seccomp
filter, which is not enabled on powerpc.
This means we have not noticed that our implementation of
syscall_set_return_value() negates error, even though the value passed
in is already negative.
So remove the negation in syscall_set_return_value(), and expect the
caller to do it like all other implementations do.
Also add a comment about the ccr handling.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | arch/powerpc/include/asm/syscall.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h index c6239dabcfb1..cabe90133e69 100644 --- a/arch/powerpc/include/asm/syscall.h +++ b/arch/powerpc/include/asm/syscall.h @@ -44,9 +44,15 @@ static inline void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val) { + /* + * In the general case it's not obvious that we must deal with CCR + * here, as the syscall exit path will also do that for us. However + * there are some places, eg. the signal code, which check ccr to + * decide if the value in r3 is actually an error. + */ if (error) { regs->ccr |= 0x10000000L; - regs->gpr[3] = -error; + regs->gpr[3] = error; } else { regs->ccr &= ~0x10000000L; regs->gpr[3] = val; |