PowerPC64 ELFv2 ABI 4/6: Stack frame layout changes

This updates glibc for the changes in the ELFv2 relating to the
stack frame layout.  These are described in more detail here:
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01149.html
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01146.html

Specifically, the "compiler and linker doublewords" were removed,
which has the effect that the save slot for the TOC register is
now at offset 24 rather than 40 to the stack pointer.

In addition, a function may now no longer necessarily assume that
its caller has set up a 64-byte register save area its use.

To address the first change, the patch goes through all assembler
files and replaces immediate offsets in instructions accessing the
ABI-defined stack slots by symbolic offsets.  Those already were
defined in ucontext_i.sym and used in some of the context routines,
but that doesn't really seem like the right place for those defines.

The patch instead defines those symbolic offsets in sysdeps.h,
in two variants for the old and new ABI, and uses them systematically
in all assembler files, not just the context routines.

The second change only affected a few assembler files that used
the save area to temporarily store some registers.  In those
cases where this happens within a leaf function, this patch
changes the code to store those registers to the "red zone"
below the stack pointer.  Otherwise, the functions already allocate
a stack frame, and the patch changes them to add extra space in
these frames as temporary space for the ELFv2 ABI.

1 files changed, 59 insertions, 17 deletions

diff --git a/sysdeps/powerpc/powerpc64/sysdep.h b/sysdeps/powerpc/powerpc64/sysdep.h
index 779fd90265..112e4187c5 100644
--- a/sysdeps/powerpc/powerpc64/sysdep.h
+++ b/sysdeps/powerpc/powerpc64/sysdep.h
@@ -20,25 +20,67 @@
 
 #ifdef __ASSEMBLER__
 
+/* Stack frame offsets.  */
+#if _CALL_ELF != 2
+#define FRAME_MIN_SIZE		112
+#define FRAME_MIN_SIZE_PARM	112
+#define FRAME_BACKCHAIN		0
+#define FRAME_CR_SAVE		8
+#define FRAME_LR_SAVE		16
+#define FRAME_TOC_SAVE		40
+#define FRAME_PARM_SAVE		48
+#define FRAME_PARM1_SAVE	48
+#define FRAME_PARM2_SAVE	56
+#define FRAME_PARM3_SAVE	64
+#define FRAME_PARM4_SAVE	72
+#define FRAME_PARM5_SAVE	80
+#define FRAME_PARM6_SAVE	88
+#define FRAME_PARM7_SAVE	96
+#define FRAME_PARM8_SAVE	104
+#define FRAME_PARM9_SAVE	112
+#else
+#define FRAME_MIN_SIZE		32
+#define FRAME_MIN_SIZE_PARM	96
+#define FRAME_BACKCHAIN		0
+#define FRAME_CR_SAVE		8
+#define FRAME_LR_SAVE		16
+#define FRAME_TOC_SAVE		24
+#define FRAME_PARM_SAVE		32
+#define FRAME_PARM1_SAVE	32
+#define FRAME_PARM2_SAVE	40
+#define FRAME_PARM3_SAVE	48
+#define FRAME_PARM4_SAVE	56
+#define FRAME_PARM5_SAVE	64
+#define FRAME_PARM6_SAVE	72
+#define FRAME_PARM7_SAVE	80
+#define FRAME_PARM8_SAVE	88
+#define FRAME_PARM9_SAVE	96
+#endif
+
 /* Support macros for CALL_MCOUNT.  */
+#if _CALL_ELF == 2
+#define call_mcount_parm_offset (-64)
+#else
+#define call_mcount_parm_offset FRAME_PARM_SAVE
+#endif
 	.macro SAVE_ARG NARG
 	.if \NARG
 	SAVE_ARG \NARG-1
-	std	2+\NARG,40+8*(\NARG)(1)
+	std	2+\NARG,call_mcount_parm_offset-8+8*(\NARG)(1)
 	.endif
 	.endm
 
 	.macro REST_ARG NARG
 	.if \NARG
 	REST_ARG \NARG-1
-	ld	2+\NARG,112+40+8*(\NARG)(1)
+	ld	2+\NARG,FRAME_MIN_SIZE_PARM+call_mcount_parm_offset-8+8*(\NARG)(1)
 	.endif
 	.endm
 
 	.macro CFI_SAVE_ARG NARG
 	.if \NARG
 	CFI_SAVE_ARG \NARG-1
-	cfi_offset(2+\NARG,40+8*(\NARG))
+	cfi_offset(2+\NARG,call_mcount_parm_offset-8+8*(\NARG))
 	.endif
 	.endm
 
@@ -55,20 +97,20 @@
 #ifdef	PROF
 	mflr	r0
 	SAVE_ARG \NARG
-	std	r0,16(r1)
-	stdu	r1,-112(r1)
-	cfi_adjust_cfa_offset(112)
-	cfi_offset(lr,16)
+	std	r0,FRAME_LR_SAVE(r1)
+	stdu	r1,-FRAME_MIN_SIZE_PARM(r1)
+	cfi_adjust_cfa_offset(FRAME_MIN_SIZE_PARM)
+	cfi_offset(lr,FRAME_LR_SAVE)
 	CFI_SAVE_ARG \NARG
 	bl	JUMPTARGET (_mcount)
 #ifndef SHARED
 	nop
 #endif
-	ld	r0,128(r1)
+	ld	r0,FRAME_MIN_SIZE_PARM+FRAME_LR_SAVE(r1)
 	REST_ARG \NARG
 	mtlr	r0
-	addi	r1,r1,112
-	cfi_adjust_cfa_offset(-112)
+	addi	r1,r1,FRAME_MIN_SIZE_PARM
+	cfi_adjust_cfa_offset(-FRAME_MIN_SIZE_PARM)
 	cfi_restore(lr)
 	CFI_REST_ARG \NARG
 #endif
@@ -267,15 +309,15 @@ LT_LABELSUFFIX(name,_name_end): ; \
     .else; \
 .Local_syscall_error: \
     mflr 0; \
-    std 0,16(1); \
-    stdu 1,-112(1); \
-    cfi_adjust_cfa_offset(112); \
-    cfi_offset(lr,16); \
+    std 0,FRAME_LR_SAVE(1); \
+    stdu 1,-FRAME_MIN_SIZE(1); \
+    cfi_adjust_cfa_offset(FRAME_MIN_SIZE); \
+    cfi_offset(lr,FRAME_LR_SAVE); \
     bl JUMPTARGET(__syscall_error); \
     nop; \
-    ld 0,112+16(1); \
-    addi 1,1,112; \
-    cfi_adjust_cfa_offset(-112); \
+    ld 0,FRAME_MIN_SIZE+FRAME_LR_SAVE(1); \
+    addi 1,1,FRAME_MIN_SIZE; \
+    cfi_adjust_cfa_offset(-FRAME_MIN_SIZE); \
     mtlr 0; \
     cfi_restore(lr); \
     blr; \