From 23e50ece453d94989cbb20c51c300f24386b08b2 Mon Sep 17 00:00:00 2001
From: Richard Henderson <rth@redhat.com>
Date: Fri, 16 Jan 2004 04:59:55 +0000
Subject:         * sysdeps/unix/sysv/linux/alpha/rt_sigaction.S: Prefix stubs
 with         __syscall_, move nop inside, adjust users by +4.

2004-01-15  Richard Henderson  <rth@redhat.com>

	* sysdeps/unix/sysv/linux/alpha/rt_sigaction.S: Prefix stubs with
	__syscall_, move nop inside, adjust users by +4.
---
 sysdeps/unix/sysv/linux/alpha/rt_sigaction.S | 54 +++++++++++++---------------
 1 file changed, 25 insertions(+), 29 deletions(-)

(limited to 'sysdeps')

diff --git a/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S b/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
index aad988b..e27949f 100644
--- a/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
+++ b/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S
@@ -26,7 +26,6 @@
 
    This just about halves signal delivery time.  */
 
-#ifdef __NR_rt_sigaction
 	.text
 
 ENTRY(__syscall_rt_sigaction)
@@ -42,12 +41,20 @@ ENTRY(__syscall_rt_sigaction)
 
 	beq	a1, 0f
 	ldl	t0, 8(a1)			# sa_flags
-	ldah	a4, sigreturn(gp)		!gprelhigh
-	ldah	t1, rt_sigreturn(gp)		!gprelhigh
-	lda	a4, sigreturn(a4)		!gprellow
-	lda	t1, rt_sigreturn(t1)		!gprellow
-	and	t0, 0x00000040, t0		# SA_SIGINFO
+
+	/* The unwinder will subtract one from the return address when
+	   attempting to find the call instruction that led us here.
+	   Since we didn't get here via a normal call, if we do nothing
+	   we would pick up the wrong symbol and the wrong FDE.  Account
+	   for this by adding a nop to the start of the function and 
+	   then skipping it here by adding 4.  */
+	ldah	a4, __syscall_sigreturn+4(gp)		!gprelhigh
+	ldah	t1, __syscall_rt_sigreturn+4(gp)	!gprelhigh
+	lda	a4, __syscall_sigreturn+4(a4)		!gprellow
+	lda	t1, __syscall_rt_sigreturn+4(t1)	!gprellow
+	and	t0, 0x40, t0				# SA_SIGINFO
 	cmovne	t0, t1, a4
+
 0:	ldi	v0, __NR_rt_sigaction
 	callsys
 	bne	a3, SYSCALL_ERROR_LABEL
@@ -57,10 +64,10 @@ PSEUDO_END(__syscall_rt_sigaction)
 
 /* To enable unwinding through the signal frame without special hackery
    elsewhere, describe the entire struct sigcontext with unwind info.
-   Note that we begin the unwind info one instruction before the start
-   of the function; the unwinder will subtract one from the return address
-   attempting to find the call instruction that led us here, since we
-   didn't get here via a normal call.  */
+
+   In order to minimize the size of the encoding, we set the CFA to the
+   end of the sigcontext, which makes all of the registers have small
+   negative offsets from that.  */
 
 	.macro SIGCONTEXT_REGS_I base, from=0
 	cfi_offset (\from, \base + (4 + \from) * 8)
@@ -91,34 +98,23 @@ PSEUDO_END(__syscall_rt_sigaction)
 	cfi_startproc
 	cfi_return_column (64)
 	SIGCONTEXT_REGS -648
+
 	cfi_def_cfa_offset (648)
+__syscall_sigreturn:
 	nop
-sigreturn:
 	mov	sp, a0
 	ldi	v0, __NR_sigreturn
 	callsys
-	cfi_endproc
-	.size	sigreturn, .-sigreturn
-	.type	sigreturn, @function
+	.size	__syscall_sigreturn, .-__syscall_sigreturn
+	.type	__syscall_sigreturn, @function
 
-	cfi_startproc
-	cfi_return_column (64)
-	SIGCONTEXT_REGS -648
 	cfi_def_cfa_offset (176 + 648)
+__syscall_rt_sigreturn:
 	nop
-rt_sigreturn:
 	mov	sp,a0
 	ldi	v0,__NR_rt_sigreturn
 	callsys
-	cfi_endproc
-	.size	rt_sigreturn, .-rt_sigreturn
-	.type	rt_sigreturn, @function
+	.size	__syscall_rt_sigreturn, .-__syscall_rt_sigreturn
+	.type	__syscall_rt_sigreturn, @function
 
-#else
-ENTRY(__syscall_rt_sigaction)
-	ldgp $29,0($27)
-	.prologue 1
-	ldi $0,ENOSYS
-	SYSCALL_ERROR_HANDLER
-END(__syscall_rt_sigaction)
-#endif
+	cfi_endproc
-- 
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