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| author |   Helge Deller <deller@gmx.de> | 2021-09-07 05:03:29 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2021-09-09 12:44:31 +0200 |
| commit | e4f2006f1287e7ea17660490569cff323772dac4 (patch) | |
| tree | cf94f68fbc02ba42c6d5a6a1b325a8bb8b67d534 | |
| parent | parisc: Check user signal stack trampoline is inside TASK_SIZE (diff) | |
| download | linux-dev-e4f2006f1287e7ea17660490569cff323772dac4.tar.xz linux-dev-e4f2006f1287e7ea17660490569cff323772dac4.zip | |
parisc: Reduce sigreturn trampoline to 3 instructions
We can move the INSN_LDI_R20 instruction into the branch delay slot.
Signed-off-by: Helge Deller <deller@gmx.de>
| -rw-r--r-- | arch/parisc/include/asm/rt_sigframe.h | 2 | ||||
| -rw-r--r-- | arch/parisc/kernel/signal.c | 13 | ||||
| -rw-r--r-- | arch/parisc/kernel/signal32.h | 2 |
3 files changed, 8 insertions, 9 deletions
diff --git a/arch/parisc/include/asm/rt_sigframe.h b/arch/parisc/include/asm/rt_sigframe.h index 2b3010ade00e..4b9e3d707571 100644 --- a/arch/parisc/include/asm/rt_sigframe.h +++ b/arch/parisc/include/asm/rt_sigframe.h @@ -2,7 +2,7 @@ #ifndef _ASM_PARISC_RT_SIGFRAME_H #define _ASM_PARISC_RT_SIGFRAME_H -#define SIGRETURN_TRAMP 4 +#define SIGRETURN_TRAMP 3 #define SIGRESTARTBLOCK_TRAMP 5 #define TRAMP_SIZE (SIGRETURN_TRAMP + SIGRESTARTBLOCK_TRAMP) diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c index 46b1050640b8..bbfe23c40c01 100644 --- a/arch/parisc/kernel/signal.c +++ b/arch/parisc/kernel/signal.c @@ -288,22 +288,21 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs, already in userspace. The first words of tramp are used to save the previous sigrestartblock trampoline that might be on the stack. We start the sigreturn trampoline at - SIGRESTARTBLOCK_TRAMP+X. */ + SIGRESTARTBLOCK_TRAMP. */ err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0, &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]); - err |= __put_user(INSN_LDI_R20, - &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); err |= __put_user(INSN_BLE_SR2_R0, + &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); + err |= __put_user(INSN_LDI_R20, &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]); - err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]); - start = (unsigned long) &frame->tramp[0]; - end = (unsigned long) &frame->tramp[TRAMP_SIZE]; + start = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]; + end = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]; flush_user_dcache_range_asm(start, end); flush_user_icache_range_asm(start, end); /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP - * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP + * TRAMP Words 5-7, Length 3 = SIGRETURN_TRAMP * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP */ rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP]; diff --git a/arch/parisc/kernel/signal32.h b/arch/parisc/kernel/signal32.h index f166250f2d06..a5bdbb5678b7 100644 --- a/arch/parisc/kernel/signal32.h +++ b/arch/parisc/kernel/signal32.h @@ -36,7 +36,7 @@ struct compat_regfile { compat_int_t rf_sar; }; -#define COMPAT_SIGRETURN_TRAMP 4 +#define COMPAT_SIGRETURN_TRAMP 3 #define COMPAT_SIGRESTARTBLOCK_TRAMP 5 #define COMPAT_TRAMP_SIZE (COMPAT_SIGRETURN_TRAMP + \ COMPAT_SIGRESTARTBLOCK_TRAMP) |