@@ -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;
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> --- arch/powerpc/include/asm/syscall.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)