[glibc/azanella/clang] aarch64: Fix gmon profiling with clang

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=0739d050cb8a6990d7ee1716bbfbf3421dbfaced

commit 0739d050cb8a6990d7ee1716bbfbf3421dbfaced
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Wed Jan 31 17:26:59 2024 +0000

    aarch64: Fix gmon profiling with clang
    
    Different than gcc, clang does not pass the LR value as the first
    argument.  To avoid requiring change clang generated code (since same
    ABI is used on other OS, like FreeBSD), use a similar strategy as x86_64
    to obtain both the frompc and the selfpc from the stack frame.
    
    Checked on aarch64-linux-gnu.

Diff:
---
 sysdeps/aarch64/Makefile                 |  3 +++
 sysdeps/aarch64/{mcount.c => __mcount.S} | 20 +++++++++++++++++---
 sysdeps/aarch64/machine-gmon.h           | 12 +++---------
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
index 141d7d9cc2..bac84c6144 100644
--- a/sysdeps/aarch64/Makefile
+++ b/sysdeps/aarch64/Makefile
@@ -54,6 +54,9 @@ gen-as-const-headers += \
 endif
 
 ifeq ($(subdir),gmon)
+sysdep_routines += \
+  __mcount \
+  # sysdep_routines
 CFLAGS-mcount.c += -mgeneral-regs-only
 endif
 
diff --git a/sysdeps/aarch64/mcount.c b/sysdeps/aarch64/__mcount.S
similarity index 72%
rename from sysdeps/aarch64/mcount.c
rename to sysdeps/aarch64/__mcount.S
index 1651ab9c8f..9688c41459 100644
--- a/sysdeps/aarch64/mcount.c
+++ b/sysdeps/aarch64/__mcount.S
@@ -1,5 +1,5 @@
-/* Copyright (C) 2013-2024 Free Software Foundation, Inc.
-
+/* AArch64 definitions for profiling support.
+   Copyright (C) 2024 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -16,9 +16,23 @@
    License along with the GNU C Library.  If not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <sysdep.h>
 #include <shlib-compat.h>
 
-#include <gmon/mcount.c>
+ENTRY (__mcount)
+	stp     x29, x30, [sp, -16]!
+	/* Note: xpaclri is needed for frompc because of gcc PR target/94791.  */
+	hint	7
+	mov	x1, x30
+	/* Load the caller return address as frompc.  */
+	ldr	x0, [x29, #8]
+	mov	x30, x0
+	mov	x0, x30
+	/* Use the return address as selfpc.  */
+	mov	x0, x30
+	ldp     x29, x30, [sp], 16
+	b	__mcount_internal
+END (__mcount)
 
 /* We forgot to add _mcount in glibc 2.17.  We added it in 2.18
    therefore we want it to be added with version GLIBC_2_18.  However,
diff --git a/sysdeps/aarch64/machine-gmon.h b/sysdeps/aarch64/machine-gmon.h
index 6890b9912b..a703f5ca4d 100644
--- a/sysdeps/aarch64/machine-gmon.h
+++ b/sysdeps/aarch64/machine-gmon.h
@@ -22,14 +22,8 @@
 
 #include <sysdep.h>
 
-static void mcount_internal (u_long frompc, u_long selfpc);
-
 #define _MCOUNT_DECL(frompc, selfpc) \
-static inline void mcount_internal (u_long frompc, u_long selfpc)
+void __mcount_internal (u_long frompc, u_long selfpc)
 
-/* Note: strip_pac is needed for frompc because of gcc PR target/94791.  */
-#define MCOUNT                                                    \
-void __mcount (void *frompc)                                      \
-{                                                                 \
-  mcount_internal ((u_long) strip_pac (frompc), (u_long) RETURN_ADDRESS (0)); \
-}
+/* Implemented by __mcount.S.  */
+#define MCOUNT