[PATCH 1/2] powerpc/signal: Fix handling of SA_RESTORER sigaction flag

[Christophe Leroy]

powerpc advertises support of SA_RESTORER sigaction flag.

Make it the truth.

Cc: sta...@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 8 ++++++--
 arch/powerpc/kernel/signal_64.c | 4 +++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 0608581967f0..cf3da1386595 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -769,7 +769,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t 
*oldset,
        }
 
        /* Save user registers on the stack */
-       if (tsk->mm->context.vdso) {
+       if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+               tramp = (unsigned long)ksig->ka.sa.sa_restorer;
+       } else if (tsk->mm->context.vdso) {
                tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp_rt32);
        } else {
                tramp = (unsigned long)mctx->mc_pad;
@@ -865,7 +867,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
        else
                unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
 
-       if (tsk->mm->context.vdso) {
+       if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+               tramp = (unsigned long)ksig->ka.sa.sa_restorer;
+       } else if (tsk->mm->context.vdso) {
                tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp32);
        } else {
                tramp = (unsigned long)mctx->mc_pad;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 1831bba0582e..fb31a334aca6 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -910,7 +910,9 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
        tsk->thread.fp_state.fpscr = 0;
 
        /* Set up to return from userspace. */
-       if (tsk->mm->context.vdso) {
+       if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+               regs_set_return_ip(regs, (unsigned 
long)ksig->ka.sa.sa_restorer);
+       } else if (tsk->mm->context.vdso) {
                regs_set_return_ip(regs, VDSO64_SYMBOL(tsk->mm->context.vdso, 
sigtramp_rt64));
        } else {
                err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
-- 
2.25.0