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>

diff --git a/arch/parisc/include/asm/rt_sigframe.h b/arch/parisc/include/asm/rt_sigframe.h
index 2b3010a..4b9e3d7 100644 (file)
--- 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 46b1050..bbfe23c 100644 (file)
--- 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 f166250..a5bdbb5 100644 (file)
--- 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)