From: Ralf Baechle Date: Tue, 8 Aug 2006 02:47:01 +0000 (+0100) Subject: [MIPS] Avoid double signal restarting. X-Git-Tag: v2.6.19-rc1~1054 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=13fdd31abec5f48cf97693bd14d2e11e0779b4ca;p=linux-2.6 [MIPS] Avoid double signal restarting. In entry.S resume_userspace ... jal do_notify_resume form a loop through which the kernel will iterate as long as work is pending. If we iterate through this loop more than once with no signal pending for at least one but the last iteration we will take do the syscall restarting multiple times resulting in a syscall return prior to the the syscall instruction in userspace. This may happen when debugging a multithreaded program. Debugging and original fix by Maciej; extended to other ABIs by me. Signed-off-by: Maciej W. Rozycki Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/kernel/irixsig.c b/arch/mips/kernel/irixsig.c index 052ea15f1e..719364752e 100644 --- a/arch/mips/kernel/irixsig.c +++ b/arch/mips/kernel/irixsig.c @@ -224,6 +224,7 @@ void do_irix_signal(struct pt_regs *regs) regs->regs[7] = regs->regs[26]; regs->cp0_epc -= 4; } + regs->regs[0] = 0; /* Don't deal with this again. */ } /* diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 56bf429113..b9d358e052 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -429,7 +429,6 @@ void do_signal(struct pt_regs *regs) else oldset = ¤t->blocked; - signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { /* Whee! Actually deliver the signal. */ @@ -464,6 +463,7 @@ void do_signal(struct pt_regs *regs) regs->regs[7] = regs->regs[26]; regs->cp0_epc -= 4; } + regs->regs[0] = 0; /* Don't deal with this again. */ } /* diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c index 282e85a7ba..c86a5ddff0 100644 --- a/arch/mips/kernel/signal32.c +++ b/arch/mips/kernel/signal32.c @@ -854,6 +854,7 @@ void do_signal32(struct pt_regs *regs) regs->regs[7] = regs->regs[26]; regs->cp0_epc -= 4; } + regs->regs[0] = 0; /* Don't deal with this again. */ } /*