Le 09/01/2021 à 04:25, Christopher M. Riedl a écrit :
Rework the messy ifdef breaking up the if-else for TM similar to
commit f1cf4f93de2f ("powerpc/signal32: Remove ifdefery in middle of if/else").
Unlike that commit for ppc32, the ifdef can't be removed entirely since
uc_transact in sigframe depends on CONFIG_PPC_TRANSACTIONAL_MEM.
Signed-off-by: Christopher M. Riedl <c...@codefail.de>
---
arch/powerpc/kernel/signal_64.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index b211a8ea4f6e..dd3787f67a78 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -710,9 +710,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
struct pt_regs *regs = current_pt_regs();
struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
sigset_t set;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
unsigned long msr;
-#endif
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
@@ -762,10 +760,12 @@ SYSCALL_DEFINE0(rt_sigreturn)
* restore_tm_sigcontexts.
*/
regs->msr &= ~MSR_TS_MASK;
+#endif
if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
goto badframe;
This means you are doing that __get_user() even when msr is not used. That
should be avoided.
if (MSR_TM_ACTIVE(msr)) {
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* We recheckpoint on return. */
struct ucontext __user *uc_transact;
@@ -778,9 +778,8 @@ SYSCALL_DEFINE0(rt_sigreturn)
if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
&uc_transact->uc_mcontext))
goto badframe;
- } else
#endif
- {
+ } else {
/*
* Fall through, for non-TM restore
*
@@ -818,10 +817,8 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
unsigned long newsp = 0;
long err = 0;
struct pt_regs *regs = tsk->thread.regs;
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* Save the thread's msr before get_tm_stackpointer() changes it */
- unsigned long msr = regs->msr;
-#endif
+ unsigned long msr __maybe_unused = regs->msr;
I don't thing __maybe_unused() is the right solution.
I think MSR_TM_ACTIVE() should be fixed instead, either by changing it into a static inline
function, or doing something similar to
https://github.com/linuxppc/linux/commit/05a4ab823983d9136a460b7b5e0d49ee709a6f86
frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
if (!access_ok(frame, sizeof(*frame)))
@@ -836,8 +833,9 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+
if (MSR_TM_ACTIVE(msr)) {
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* The ucontext_t passed to userland points to the second
* ucontext_t (for transactional state) with its uc_link ptr.
*/
@@ -847,9 +845,8 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
tsk, ksig->sig, NULL,
(unsigned
long)ksig->ka.sa.sa_handler,
msr);
- } else
#endif
- {
+ } else {
err |= __put_user(0, &frame->uc.uc_link);
prepare_setup_sigcontext(tsk, 1);
err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
Christophe
