diff options
| author | Al Viro <viro@ftp.linux.org.uk> | 2010-09-28 18:50:37 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2010-10-18 16:59:02 +0100 |
| commit | 8f5a00eb422ed86e77bb8f67e08b9fe6d30f679a (patch) | |
| tree | 6b625361c9581fb71fd2d005b5de54804d4f9798 /arch/mips/kernel/signal.c | |
| parent | e5b377a8fb7b05f27647698ac739a0504cb2bf80 (diff) | |
MIPS: Sanitize restart logics
Put the original syscall number into ->regs[0] when we leave syscall
with error. Use it in restart logics. Everything else will have
it 0 since we pass through SAVE_SOME on all the ways in. Note that
in places like bad_stack and inllegal_syscall we leave it 0 - it's not
restartable.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1698/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/signal.c')
| -rw-r--r-- | arch/mips/kernel/signal.c | 37 |
1 files changed, 18 insertions, 19 deletions
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index b3273aeaeed..604f077bb5b 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -550,23 +550,26 @@ static int handle_signal(unsigned long sig, siginfo_t *info, struct mips_abi *abi = current->thread.abi; void *vdso = current->mm->context.vdso; - switch(regs->regs[0]) { - case ERESTART_RESTARTBLOCK: - case ERESTARTNOHAND: - regs->regs[2] = EINTR; - break; - case ERESTARTSYS: - if (!(ka->sa.sa_flags & SA_RESTART)) { + if (regs->regs[0]) { + switch(regs->regs[2]) { + case ERESTART_RESTARTBLOCK: + case ERESTARTNOHAND: regs->regs[2] = EINTR; break; + case ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->regs[2] = EINTR; + break; + } + /* fallthrough */ + case ERESTARTNOINTR: + regs->regs[7] = regs->regs[26]; + regs->regs[2] = regs->regs[0]; + regs->cp0_epc -= 4; } - /* fallthrough */ - case ERESTARTNOINTR: /* Userland will reload $v0. */ - regs->regs[7] = regs->regs[26]; - regs->cp0_epc -= 8; - } - regs->regs[0] = 0; /* Don't deal with this again. */ + regs->regs[0] = 0; /* Don't deal with this again. */ + } if (sig_uses_siginfo(ka)) ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset, @@ -625,17 +628,13 @@ static void do_signal(struct pt_regs *regs) return; } - /* - * Who's code doesn't conform to the restartable syscall convention - * dies here!!! The li instruction, a single machine instruction, - * must directly be followed by the syscall instruction. - */ if (regs->regs[0]) { if (regs->regs[2] == ERESTARTNOHAND || regs->regs[2] == ERESTARTSYS || regs->regs[2] == ERESTARTNOINTR) { + regs->regs[2] = regs->regs[0]; regs->regs[7] = regs->regs[26]; - regs->cp0_epc -= 8; + regs->cp0_epc -= 4; } if (regs->regs[2] == ERESTART_RESTARTBLOCK) { regs->regs[2] = current->thread.abi->restart; |