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.

2 files changed, 47 insertions, 26 deletions

diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index 9f40630..64dc17f 100644
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,3 +1,16 @@
+2013-12-04  Ulrich Weigand  <Ulrich.Weigand@de.ibm.com>
+
+	* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep-cancel.h
+	(CANCEL_FRAMESIZE, CANCEL_PARM_SAVE): New macros to save parameters
+	into our own stack frame instead of the caller's.
+	(PSEUDO): Use them.  Use symbolic stack frame offsets.
+	(DOCARGS_1, UNDOCARGS_1): Use CANCEL_PARM_SAVE.
+	(DOCARGS_2, UNDOCARGS_2): Likewise.
+	(DOCARGS_3, UNDOCARGS_3): Likewise.
+	(DOCARGS_4, UNDOCARGS_4): Likewise.
+	(DOCARGS_5, UNDOCARGS_5): Likewise.
+	(DOCARGS_6, UNDOCARGS_6): Likewise.
+
 2013-11-26  Ondřej Bílka  <neleai@seznam.cz>
 	* sysdeps/i386/tls.h: Use __glibc_reserved instead __unused.
 	* sysdeps/x86_64/tls.h: Likewise.
diff --git a/nptl/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep-cancel.h b/nptl/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep-cancel.h
index 51e021d..d711dc6 100644
--- a/nptl/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep-cancel.h
+++ b/nptl/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep-cancel.h
@@ -31,6 +31,14 @@
 #  define DASHDASHPFX(str) __##str
 # endif
 
+#if _CALL_ELF == 2
+#define CANCEL_FRAMESIZE (FRAME_MIN_SIZE+16+48)
+#define CANCEL_PARM_SAVE (FRAME_MIN_SIZE+16)
+#else
+#define CANCEL_FRAMESIZE (FRAME_MIN_SIZE+16)
+#define CANCEL_PARM_SAVE (CANCEL_FRAMESIZE+FRAME_PARM_SAVE)
+#endif
+
 # undef PSEUDO
 # define PSEUDO(name, syscall_name, args)				\
   .section ".text";							\
@@ -44,52 +52,52 @@
     PSEUDO_RET;								\
   .size DASHDASHPFX(syscall_name##_nocancel),.-DASHDASHPFX(syscall_name##_nocancel);	\
   .Lpseudo_cancel:							\
-    stdu 1,-128(1);							\
-    cfi_adjust_cfa_offset (128);					\
+    stdu 1,-CANCEL_FRAMESIZE(1);					\
+    cfi_adjust_cfa_offset (CANCEL_FRAMESIZE);				\
     mflr 9;								\
-    std  9,128+16(1);							\
-    cfi_offset (lr, 16);						\
+    std  9,CANCEL_FRAMESIZE+FRAME_LR_SAVE(1);				\
+    cfi_offset (lr, FRAME_LR_SAVE);					\
     DOCARGS_##args;	/* save syscall args around CENABLE.  */	\
     CENABLE;								\
-    std  3,112(1);	/* store CENABLE return value (MASK).  */	\
+    std  3,FRAME_MIN_SIZE(1); /* store CENABLE return value (MASK).  */	\
     UNDOCARGS_##args;	/* restore syscall args.  */			\
     DO_CALL (SYS_ify (syscall_name));					\
     mfcr 0;		/* save CR/R3 around CDISABLE.  */		\
-    std  3,120(1);							\
-    std  0,128+8(1);							\
-    cfi_offset (cr, 8);							\
-    ld   3,112(1);	/* pass MASK to CDISABLE.  */			\
+    std  3,FRAME_MIN_SIZE+8(1);						\
+    std  0,CANCEL_FRAMESIZE+FRAME_CR_SAVE(1);				\
+    cfi_offset (cr, FRAME_CR_SAVE);					\
+    ld   3,FRAME_MIN_SIZE(1); /* pass MASK to CDISABLE.  */		\
     CDISABLE;								\
-    ld   9,128+16(1);							\
-    ld   0,128+8(1);	/* restore CR/R3. */				\
-    ld   3,120(1);							\
+    ld   9,CANCEL_FRAMESIZE+FRAME_LR_SAVE(1);				\
+    ld   0,CANCEL_FRAMESIZE+FRAME_CR_SAVE(1); /* restore CR/R3. */	\
+    ld   3,FRAME_MIN_SIZE+8(1);						\
     mtlr 9;								\
     mtcr 0;								\
-    addi 1,1,128;							\
-    cfi_adjust_cfa_offset (-128);					\
+    addi 1,1,CANCEL_FRAMESIZE;						\
+    cfi_adjust_cfa_offset (-CANCEL_FRAMESIZE);				\
     cfi_restore (lr);							\
     cfi_restore (cr)
 
 # define DOCARGS_0
 # define UNDOCARGS_0
 
-# define DOCARGS_1	std 3,128+48(1); DOCARGS_0
-# define UNDOCARGS_1	ld 3,128+48(1); UNDOCARGS_0
+# define DOCARGS_1	std 3,CANCEL_PARM_SAVE(1); DOCARGS_0
+# define UNDOCARGS_1	ld 3,CANCEL_PARM_SAVE(1); UNDOCARGS_0
 
-# define DOCARGS_2	std 4,128+56(1); DOCARGS_1
-# define UNDOCARGS_2	ld 4,128+56(1); UNDOCARGS_1
+# define DOCARGS_2	std 4,CANCEL_PARM_SAVE+8(1); DOCARGS_1
+# define UNDOCARGS_2	ld 4,CANCEL_PARM_SAVE+8(1); UNDOCARGS_1
 
-# define DOCARGS_3	std 5,128+64(1); DOCARGS_2
-# define UNDOCARGS_3	ld 5,128+64(1); UNDOCARGS_2
+# define DOCARGS_3	std 5,CANCEL_PARM_SAVE+16(1); DOCARGS_2
+# define UNDOCARGS_3	ld 5,CANCEL_PARM_SAVE+16(1); UNDOCARGS_2
 
-# define DOCARGS_4	std 6,128+72(1); DOCARGS_3
-# define UNDOCARGS_4	ld 6,128+72(1); UNDOCARGS_3
+# define DOCARGS_4	std 6,CANCEL_PARM_SAVE+24(1); DOCARGS_3
+# define UNDOCARGS_4	ld 6,CANCEL_PARM_SAVE+24(1); UNDOCARGS_3
 
-# define DOCARGS_5	std 7,128+80(1); DOCARGS_4
-# define UNDOCARGS_5	ld 7,128+80(1); UNDOCARGS_4
+# define DOCARGS_5	std 7,CANCEL_PARM_SAVE+32(1); DOCARGS_4
+# define UNDOCARGS_5	ld 7,CANCEL_PARM_SAVE+32(1); UNDOCARGS_4
 
-# define DOCARGS_6	std 8,128+88(1); DOCARGS_5
-# define UNDOCARGS_6	ld 8,128+88(1); UNDOCARGS_5
+# define DOCARGS_6	std 8,CANCEL_PARM_SAVE+40(1); DOCARGS_5
+# define UNDOCARGS_6	ld 8,CANCEL_PARM_SAVE+40(1); UNDOCARGS_5
 
 # ifdef IS_IN_libpthread
 #  ifdef SHARED