diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2020-05-07 22:13:32 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-15 11:58:54 +1000 |
| commit | 4e0e45b07d790253643ee05300784ab2156e2d5e (patch) | |
| tree | 8945f0e66bed685345be9fa12472e21893db7a41 /arch/powerpc/kernel/signal_32.c | |
| parent | 912237ea166428edcbf3c137adf12cb987c477f2 (diff) | |
powerpc: Use trap metadata to prevent double restart rather than zeroing trap
It's not very nice to zero trap for this, because then system calls no
longer have trap_is_syscall(regs) invariant, and we can't distinguish
between sc and scv system calls (in a later patch).
Take one last unused bit from the low bits of the pt_regs.trap word
for this instead. There is not a really good reason why it should be
in trap as opposed to another field, but trap has some concept of
flags and it exists. Ideally I think we would move trap to 2-byte
field and have 2 more bytes available independently.
Add a selftests case for this, which can be seen to fail if
trap_norestart() is changed to return false.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make them static inlines]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200507121332.2233629-4-mpe@ellerman.id.au
Diffstat (limited to 'arch/powerpc/kernel/signal_32.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 4f96d29a22bf..ae3da7440b2f 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -500,7 +500,7 @@ static long restore_user_regs(struct pt_regs *regs, if (!sig) save_r2 = (unsigned int)regs->gpr[2]; err = restore_general_regs(regs, sr); - regs->trap = 0; + set_trap_norestart(regs); err |= __get_user(msr, &sr->mc_gregs[PT_MSR]); if (!sig) regs->gpr[2] = (unsigned long) save_r2; |