Hi Chris,
> Rework the messy ifdef breaking up the if-else for TM similar to
> commit f1cf4f93de2f ("powerpc/signal32: Remove ifdefery in middle of
> if/else").
I'm not sure what 'the messy ifdef' and 'the if-else for TM' is (yet):
perhaps you could start the commit message with a tiny bit of
background.
> 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 | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
> index b211a8ea4f6e..8e1d804ce552 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;
> @@ -765,7 +763,10 @@ SYSCALL_DEFINE0(rt_sigreturn)
>
> if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
> goto badframe;
> +#endif
> +
> if (MSR_TM_ACTIVE(msr)) {
> +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> /* We recheckpoint on return. */
> struct ucontext __user *uc_transact;
>
> @@ -778,9 +779,8 @@ 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
> *
I think you can get rid of all the ifdefs in _this function_ by
providing a couple of stubs:
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index a66f435dabbf..19059a4b798f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1120,6 +1120,7 @@ void restore_tm_state(struct pt_regs *regs)
#else
#define tm_recheckpoint_new_task(new)
#define __switch_to_tm(prev, new)
+void tm_reclaim_current(uint8_t cause) {}
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
static inline void save_sprs(struct thread_struct *t)
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 8e1d804ce552..ed58ca019ad9 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -594,6 +594,13 @@ static long restore_tm_sigcontexts(struct task_struct *tsk,
return err;
}
+#else
+static long restore_tm_sigcontexts(struct task_struct *tsk,
+ struct sigcontext __user *sc,
+ struct sigcontext __user *tm_sc)
+{
+ return -EINVAL;
+}
#endif
/*
@@ -722,7 +729,6 @@ SYSCALL_DEFINE0(rt_sigreturn)
goto badframe;
set_current_blocked(&set);
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/*
* If there is a transactional state then throw it away.
* The purpose of a sigreturn is to destroy all traces of the
@@ -763,10 +769,8 @@ SYSCALL_DEFINE0(rt_sigreturn)
if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
goto badframe;
-#endif
if (MSR_TM_ACTIVE(msr)) {
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* We recheckpoint on return. */
struct ucontext __user *uc_transact;
@@ -779,7 +783,6 @@ SYSCALL_DEFINE0(rt_sigreturn)
if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
&uc_transact->uc_mcontext))
goto badframe;
-#endif
} else {
/*
* Fall through, for non-TM restore
My only concern here was whether it was valid to access
if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
if CONFIG_PPC_TRANSACTIONAL_MEM was not defined, but I didn't think of
any obvious reason why it wouldn't be...
> @@ -818,10 +818,8 @@ 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
I wondered if that comment still makes sense in the absence of the
ifdef. It is preserved in commit f1cf4f93de2f ("powerpc/signal32: Remove
ifdefery in middle of if/else"), and I can't figure out how you would
improve it, so I guess it's probably good as it is.
> frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
> if (!access_ok(frame, sizeof(*frame)))
> @@ -836,8 +834,9 @@ 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 +846,8 @@ 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,
That seems reasonable to me.
Kind regards,
Daniel
