From efbe665c3a2d344b0d64456cf29499ba53c2965a Mon Sep 17 00:00:00 2001
From: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Mon, 11 Jul 2016 09:46:08 +0100
Subject: [PATCH] [AArch64] Fix libc internal asm profiling code

When glibc is built with --enable-profile, the ENTRY of
asm functions includes CALL_MCOUNT for profiling.
(matters for binaries static linked against libc_p.a.)

CALL_MCOUNT did not save/restore argument registers
around the _mcount call so it clobbered them.
(it is enough to only save/restore the arguments passed
to a given asm function, but that would be too many asm
changes so it is simpler to always save all argument
registers in this macro.)

float args are not saved: mcount does not clobber the
float regs and currently no asm function takes float
arguments anyway.

	[BZ #18707]
	* sysdeps/aarch64/Makefile (CFLAGS-mcount.c): Add -mgeneral-regs-only.
	* sysdeps/aarch64/sysdep.h (CALL_MCOUNT): Save argument registers.
---
 ChangeLog                |  6 ++++++
 sysdeps/aarch64/Makefile |  4 ++++
 sysdeps/aarch64/sysdep.h | 33 +++++++++++++++++++++++++++++++--
 3 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 222e4d326d..8e230e9780 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-07-11  Szabolcs Nagy  <szabolcs.nagy@arm.com>
+
+	[BZ #18707]
+	* sysdeps/aarch64/Makefile (CFLAGS-mcount.c): Add -mgeneral-regs-only.
+	* sysdeps/aarch64/sysdep.h (CALL_MCOUNT): Save argument registers.
+
 2016-07-08  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
 	* sysdeps/unix/sysv/linux/sysdep.h
diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
index 06323550e9..562c1373ae 100644
--- a/sysdeps/aarch64/Makefile
+++ b/sysdeps/aarch64/Makefile
@@ -12,3 +12,7 @@ endif
 ifeq ($(subdir),csu)
 gen-as-const-headers += tlsdesc.sym
 endif
+
+ifeq ($(subdir),gmon)
+CFLAGS-mcount.c += -mgeneral-regs-only
+endif
diff --git a/sysdeps/aarch64/sysdep.h b/sysdeps/aarch64/sysdep.h
index 6b728ec651..e0457593fc 100644
--- a/sysdeps/aarch64/sysdep.h
+++ b/sysdeps/aarch64/sysdep.h
@@ -66,9 +66,38 @@
 /* If compiled for profiling, call `mcount' at the start of each function.  */
 #ifdef	PROF
 # define CALL_MCOUNT						\
-	str	x30, [sp, #-16]!;				\
+	str	x30, [sp, #-80]!;				\
+	cfi_adjust_cfa_offset (80);				\
+	cfi_rel_offset (x30, 0);				\
+	stp	x0, x1, [sp, #16];				\
+	cfi_rel_offset (x0, 16);				\
+	cfi_rel_offset (x1, 24);				\
+	stp	x2, x3, [sp, #32];				\
+	cfi_rel_offset (x2, 32);				\
+	cfi_rel_offset (x3, 40);				\
+	stp	x4, x5, [sp, #48];				\
+	cfi_rel_offset (x4, 48);				\
+	cfi_rel_offset (x5, 56);				\
+	stp	x6, x7, [sp, #64];				\
+	cfi_rel_offset (x6, 64);				\
+	cfi_rel_offset (x7, 72);				\
+	mov	x0, x30;					\
 	bl	mcount;						\
-	ldr	x30, [sp], #16	;
+	ldp	x0, x1, [sp, #16];				\
+	cfi_restore (x0);					\
+	cfi_restore (x1);					\
+	ldp	x2, x3, [sp, #32];				\
+	cfi_restore (x2);					\
+	cfi_restore (x3);					\
+	ldp	x4, x5, [sp, #48];				\
+	cfi_restore (x4);					\
+	cfi_restore (x5);					\
+	ldp	x6, x7, [sp, #64];				\
+	cfi_restore (x6);					\
+	cfi_restore (x7);					\
+	ldr	x30, [sp], #80;					\
+	cfi_adjust_cfa_offset (-80);				\
+	cfi_restore (x30);
 #else
 # define CALL_MCOUNT		/* Do nothing.  */
 #endif