[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.

diff --git a/ChangeLog b/ChangeLog
index 222e4d326d0c49daae2a301be5aceade60cbd7e2..8e230e978007488f2bbd29df77d10a6b619071a3 100644 (file)
--- 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 06323550e947caa282a58e0dcf57888e8cf789d7..562c1373aebee6ffb4ff5c2071a23d007a8e07ba 100644 (file)
--- 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 6b728ec6516c3b9632b0ecd953a9f9b3afa928f8..e0457593fc7690733a3a0f32bbb59a1377102942 100644 (file)
--- 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