[PATCH v2 16/25] powerpc/signal32: Move signal trampoline setup to handle_[rt_]signal32

From: Christophe Leroy
Date: Tue Aug 18 2020 - 13:20:50 EST

Move signal trampoline setup into handle_signal32()
and handle_rt_signal32().

At the same time, remove the define which hides the mc_pad field
used for trampoline.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/signal_32.c | 61 ++++++++++++---------------------
1 file changed, 22 insertions(+), 39 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index ab8c8cb98b15..d8c3843102df 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -199,9 +199,6 @@ struct sigframe {
int abigap[56];
};

-/* We use the mc_pad field for the signal return trampoline. */
-#define tramp mc_pad
-
/*
* When we have rt signals to deliver, we set up on the
* user stack, going down from the original stack pointer:
@@ -236,8 +233,7 @@ struct rt_sigframe {
* altivec/spe instructions at some point.
*/
static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
- struct mcontext __user *tm_frame, int sigret,
- int ctx_has_vsx_region)
+ struct mcontext __user *tm_frame, int ctx_has_vsx_region)
{
unsigned long msr = regs->msr;

@@ -320,15 +316,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
return 1;

- if (sigret) {
- /* Set up the sigreturn trampoline: li 0,sigret; sc */
- if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
- || __put_user(PPC_INST_SC, &frame->tramp[1]))
- return 1;
- flush_icache_range((unsigned long) &frame->tramp[0],
- (unsigned long) &frame->tramp[2]);
- }
-
return 0;
}

@@ -342,10 +329,8 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
*
* See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
*/
-static int save_tm_user_regs(struct pt_regs *regs,
- struct mcontext __user *frame,
- struct mcontext __user *tm_frame, int sigret,
- unsigned long msr)
+static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
+ struct mcontext __user *tm_frame, unsigned long msr)
{
WARN_ON(tm_suspend_disabled);

@@ -461,14 +446,6 @@ static int save_tm_user_regs(struct pt_regs *regs,

if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
return 1;
- if (sigret) {
- /* Set up the sigreturn trampoline: li 0,sigret; sc */
- if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
- || __put_user(PPC_INST_SC, &frame->tramp[1]))
- return 1;
- flush_icache_range((unsigned long) &frame->tramp[0],
- (unsigned long) &frame->tramp[2]);
- }

return 0;
}
@@ -755,7 +732,6 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
struct mcontext __user *mctx;
struct mcontext __user *tm_mctx = NULL;
unsigned long newsp = 0;
- int sigret;
unsigned long tramp;
struct pt_regs *regs = tsk->thread.regs;
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -782,11 +758,15 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,

/* Save user registers on the stack */
if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
- sigret = 0;
tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
} else {
- sigret = __NR_rt_sigreturn;
- tramp = (unsigned long)mctx->tramp;
+ tramp = (unsigned long)mctx->mc_pad;
+ /* Set up the sigreturn trampoline: li r0,sigret; sc */
+ if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
+ goto badframe;
+ if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
+ goto badframe;
+ flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
}

#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -796,7 +776,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
__put_user((unsigned long)tm_mctx,
&frame->uc_transact.uc_regs))
goto badframe;
- if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
+ if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
goto badframe;
}
else
@@ -804,7 +784,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
{
if (__put_user(0, &frame->uc.uc_link))
goto badframe;
- if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
+ if (save_user_regs(regs, mctx, tm_mctx, 1))
goto badframe;
}
regs->link = tramp;
@@ -847,7 +827,6 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
struct mcontext __user *mctx;
struct mcontext __user *tm_mctx = NULL;
unsigned long newsp = 0;
- int sigret;
unsigned long tramp;
struct pt_regs *regs = tsk->thread.regs;
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -880,22 +859,26 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
goto badframe;

if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
- sigret = 0;
tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
} else {
- sigret = __NR_sigreturn;
- tramp = (unsigned long)mctx->tramp;
+ tramp = (unsigned long)mctx->mc_pad;
+ /* Set up the sigreturn trampoline: li r0,sigret; sc */
+ if (__put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0]))
+ goto badframe;
+ if (__put_user(PPC_INST_SC, &mctx->mc_pad[1]))
+ goto badframe;
+ flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));
}

#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
if (MSR_TM_ACTIVE(msr)) {
- if (save_tm_user_regs(regs, mctx, tm_mctx, sigret, msr))
+ if (save_tm_user_regs(regs, mctx, tm_mctx, msr))
goto badframe;
}
else
#endif
{
- if (save_user_regs(regs, mctx, tm_mctx, sigret, 1))
+ if (save_user_regs(regs, mctx, tm_mctx, 1))
goto badframe;
}

@@ -1047,7 +1030,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
mctx = (struct mcontext __user *)
((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
if (!access_ok(old_ctx, ctx_size)
- || save_user_regs(regs, mctx, NULL, 0, ctx_has_vsx_region)
+ || save_user_regs(regs, mctx, NULL, ctx_has_vsx_region)
|| put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
|| __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
return -EFAULT;
--
2.25.0