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Subject[PATCH 7/9] powerpc/signal: Use code patching instead of hardcoding
Date
Instead of hardcoding code modifications, use code patching functions.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/ppc-opcode.h | 1 +
arch/powerpc/kernel/signal_32.c | 12 ++++++------
arch/powerpc/kernel/signal_64.c | 7 ++++---
3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index a6e9e314c707..7f693e0f7499 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -257,6 +257,7 @@
#define PPC_INST_MTSPR_DSCR_USER_MASK 0xfc1ffffe
#define PPC_INST_MFVSRD 0x7c000066
#define PPC_INST_MTVSRD 0x7c000166
+#define PPC_INST_SC 0x44000002
#define PPC_INST_SLBFEE 0x7c0007a7
#define PPC_INST_SLBIA 0x7c0003e4

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index e6474a45cef5..9d39e0eb03ff 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -470,9 +470,9 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
return 1;

if (sigret) {
- /* Set up the sigreturn trampoline: li r0,sigret; sc */
- if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
- || __put_user(0x44000002UL, &frame->tramp[1]))
+ /* 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]);
@@ -619,9 +619,9 @@ 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 r0,sigret; sc */
- if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
- || __put_user(0x44000002UL, &frame->tramp[1]))
+ /* 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]);
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 83d51bf586c7..e53ad11be385 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -598,11 +598,12 @@ static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
long err = 0;

/* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
- err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
+ err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) |
+ (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
/* li r0, __NR_[rt_]sigreturn| */
- err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
+ err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[1]);
/* sc */
- err |= __put_user(0x44000002UL, &tramp[2]);
+ err |= __put_user(PPC_INST_SC, &tramp[2]);

/* Minimal traceback info */
for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
--
2.13.3
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