From: He Sheng hesheng@wxiat.com
Sunway inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I56YJ1
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Original implementation has deprecated sigframe and always use rt_sigframe for signal handler. But glibc remain unchanged, where handler takes $a2 as sigcontext pointer when SA_SIGINFO is not set and compatibility is break. As on sw64, SA_SIGINFO is not only a flag to specify sa_sigaction but also a flag to specify rt_sigframe and rt_sigreturn. It used to setup old sigframe and specify sigreturn for handler if SA_SIGINFO is not set.
To maintain compatibility, this patch set $a1 with exception code and and set $a2 with sigcontext pointer in that case, which seems a mix of modern rt_sigframe and traditional sigframe.
Actually, it is unnecessary to setup rt_sigframe for non SA_SIGINFO handler, because a rt_sigframe is larger than sigframe. Maybe the old sigframe will be reverted some day.
Signed-off-by: He Sheng hesheng@wxiat.com
Signed-off-by: Gu Zitao guzitao@wxiat.com --- arch/sw_64/kernel/signal.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/sw_64/kernel/signal.c b/arch/sw_64/kernel/signal.c index 17cc9850daaa..8b966e1c38aa 100644 --- a/arch/sw_64/kernel/signal.c +++ b/arch/sw_64/kernel/signal.c @@ -240,7 +240,8 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) if (!access_ok(frame, sizeof(*frame))) return -EFAULT;
- err |= copy_siginfo_to_user(&frame->info, &ksig->info); + if (ksig->ka.sa.sa_flags & SA_SIGINFO) + err |= copy_siginfo_to_user(&frame->info, &ksig->info);
/* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); @@ -262,8 +263,15 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) regs->r26 = r26; regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler; regs->r16 = ksig->sig; /* a0: signal number */ - regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */ - regs->r18 = (unsigned long) &frame->uc; /* a2: ucontext pointer */ + if (ksig->ka.sa.sa_flags & SA_SIGINFO) { + /* a1: siginfo pointer, a2: ucontext pointer */ + regs->r17 = (unsigned long) &frame->info; + regs->r18 = (unsigned long) &frame->uc; + } else { + /* a1: exception code, a2: sigcontext pointer */ + regs->r17 = 0; + regs->r18 = (unsigned long) &frame->uc.uc_mcontext; + } wrusp((unsigned long) frame);
#if DEBUG_SIG