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|
Revert the patch below.
Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>
---
From 2dcd7ed8fd149a5aefc8c7a7ff041ff389348b4f Mon Sep 17 00:00:00 2001
From: Daniel Jacobowitz <dan@codesourcery.com>
Date: Thu, 8 Apr 2010 12:43:55 -0400
Subject: [PATCH] Fix unwinding through Thumb-2 system calls.
---
ChangeLog.arm | 9 ---
sysdeps/unix/sysv/linux/arm/eabi/Makefile | 31 ------------
sysdeps/unix/sysv/linux/arm/eabi/libc-do-syscall.S | 43 -----------------
sysdeps/unix/sysv/linux/arm/eabi/nptl/aio_misc.h | 52 +++++++++++++++++++++
sysdeps/unix/sysv/linux/arm/eabi/sysdep.h | 38 ++++++---------
5 files changed, 69 insertions(+), 104 deletions(-)
create mode 100644 sysdeps/unix/sysv/linux/arm/eabi/libc-do-syscall.S
delete mode 100644 sysdeps/unix/sysv/linux/arm/eabi/nptl/aio_misc.h
Index: glibc-ports-2.13/ChangeLog.arm
===================================================================
--- glibc-ports-2.13.orig/ChangeLog.arm
+++ glibc-ports-2.13/ChangeLog.arm
@@ -68,15 +68,6 @@
* sysdeps/unix/sysv/linux/arm/eabi/internal_recvmmsg.S: New.
-2010-04-08 Daniel Jacobowitz <dan@codesourcery.com>
-
- * sysdeps/unix/sysv/linux/arm/eabi/libc-do-syscall.S: New file.
- * sysdeps/unix/sysv/linux/arm/eabi/sysdep.h [__thumb__]
- (INTERNAL_SYSCALL_RAW): Rewrite to use __libc_do_syscall.
- * sysdeps/unix/sysv/linux/arm/eabi/Makefile: Add libc-do-syscall
- to libraries and tests that require it.
- * sysdeps/unix/sysv/linux/arm/eabi/nptl/aio_misc.h: Delete.
-
2010-03-30 Joseph Myers <joseph@codesourcery.com>
* sysdeps/arm/dl-machine.h (VALID_ELF_ABIVERSION, VALID_ELF_OSABI,
Index: glibc-ports-2.13/sysdeps/unix/sysv/linux/arm/eabi/libc-do-syscall.S
===================================================================
--- glibc-ports-2.13.orig/sysdeps/unix/sysv/linux/arm/eabi/libc-do-syscall.S
+++ /dev/null
@@ -1,43 +0,0 @@
-/* Copyright (C) 2010 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
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
-
-#include <sysdep.h>
-
-/* Out-of-line syscall stub. We expect the system call number in ip
- and return the raw result in r0. No registers are clobbered.
- We could avoid using the stack for this, but the goal is accurate
- unwind information - and while there is a reserved prefix in the
- ARM unwind tables for register to register moves, the actual opcodes
- are not defined. */
-
- .thumb
- .syntax unified
- .hidden __libc_do_syscall
-
-ENTRY (__libc_do_syscall)
- .fnstart
- push {r7, lr}
- .save {r7, lr}
- cfi_adjust_cfa_offset (8)
- cfi_rel_offset (r7, 0)
- cfi_rel_offset (lr, 4)
- mov r7, ip
- swi 0x0
- pop {r7, pc}
- .fnend
-END (__libc_do_syscall)
Index: glibc-ports-2.13/sysdeps/unix/sysv/linux/arm/eabi/Makefile
===================================================================
--- glibc-ports-2.13.orig/sysdeps/unix/sysv/linux/arm/eabi/Makefile
+++ glibc-ports-2.13/sysdeps/unix/sysv/linux/arm/eabi/Makefile
@@ -7,34 +7,3 @@ ifeq ($(subdir),csu)
# unwind tables for __libc_start_main.
CFLAGS-libc-start.c += -fexceptions
endif
-
-# Add a syscall function to each library that needs one.
-
-ifeq ($(subdir),rt)
-librt-sysdep_routines += libc-do-syscall
-librt-shared-only-routines += libc-do-syscall
-endif
-
-ifeq ($(subdir),nptl)
-libpthread-sysdep_routines += libc-do-syscall
-libpthread-shared-only-routines += libc-do-syscall
-endif
-
-ifeq ($(subdir),resolv)
-libanl-sysdep_routines += libc-do-syscall
-libanl-shared-only-routines += libc-do-syscall
-endif
-
-ifeq ($(subdir),csu)
-sysdep_routines += libc-do-syscall
-endif
-
-ifeq ($(subdir),nscd)
-nscd-modules += libc-do-syscall
-endif
-
-ifeq ($(subdir),posix)
-LDFLAGS-tst-rfc3484 += $(common-objpfx)csu/libc-do-syscall.o
-LDFLAGS-tst-rfc3484-2 += $(common-objpfx)csu/libc-do-syscall.o
-LDFLAGS-tst-rfc3484-3 += $(common-objpfx)csu/libc-do-syscall.o
-endif
Index: glibc-ports-2.13/sysdeps/unix/sysv/linux/arm/eabi/nptl/aio_misc.h
===================================================================
--- /dev/null
+++ glibc-ports-2.13/sysdeps/unix/sysv/linux/arm/eabi/nptl/aio_misc.h
@@ -0,0 +1,52 @@
+/* Copyright (C) 2008 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
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include_next <aio_misc.h>
+
+#ifdef __thumb2__
+
+#include <errno.h>
+
+/* The Thumb-2 definition of INTERNAL_SYSCALL_RAW has to hide the use
+ of r7 from the compiler because it cannot handle asm clobbering the
+ hard frame pointer. In aio_suspend, GCC does not eliminate the
+ hard frame pointer because the function uses variable-length
+ arrays, so it generates unwind information using r7 as virtual
+ stack pointer. During system calls, when r7 has been saved on the
+ stack, this means the unwind information is invalid. Without extra
+ unwind directives, which would need to cause unwind information for
+ the asm to be generated separately from that for the parts of the
+ function before and after the asm (with three index table entries),
+ it is not possible to represent any temporary change to the virtual
+ stack pointer. Instead, we move the problematic system calls out
+ of line into a function that does not require a frame pointer. */
+
+static __attribute_noinline__ void
+aio_misc_wait (int *resultp,
+ volatile int *futexp,
+ const struct timespec *timeout,
+ int cancel)
+{
+ AIO_MISC_WAIT (*resultp, *futexp, timeout, cancel);
+}
+
+#undef AIO_MISC_WAIT
+#define AIO_MISC_WAIT(result, futex, timeout, cancel) \
+ aio_misc_wait (&result, &futex, timeout, cancel)
+
+#endif
Index: glibc-ports-2.13/sysdeps/unix/sysv/linux/arm/eabi/sysdep.h
===================================================================
--- glibc-ports-2.13.orig/sysdeps/unix/sysv/linux/arm/eabi/sysdep.h
+++ glibc-ports-2.13/sysdeps/unix/sysv/linux/arm/eabi/sysdep.h
@@ -44,34 +44,30 @@
argument; otherwise the (optional) compatibility code for APCS binaries
may be invoked. */
-#if defined(__thumb__)
-/* We can not expose the use of r7 to the compiler. GCC (as
- of 4.5) uses r7 as the hard frame pointer for Thumb - although
- for Thumb-2 it isn't obviously a better choice than r11.
- And GCC does not support asms that conflict with the frame
- pointer.
-
- This would be easier if syscall numbers never exceeded 255,
- but they do. For the moment the LOAD_ARGS_7 is sacrificed.
+#ifdef __thumb__
+/* Hide the use of r7 from the compiler, this would be a lot
+ easier but for the fact that the syscalls can exceed 255.
+ For the moment the LOAD_ARGS_7 is sacrificed.
We can't use push/pop inside the asm because that breaks
- unwinding (i.e. thread cancellation) for this frame. We can't
- locally save and restore r7, because we do not know if this
- function uses r7 or if it is our caller's r7; if it is our caller's,
- then unwinding will fail higher up the stack. So we move the
- syscall out of line and provide its own unwind information. */
+ unwinding (ie. thread cancellation). */
+/* FIXME: the str / ldr of r7 are not covered by CFI information. */
#undef LOAD_ARGS_7
#undef INTERNAL_SYSCALL_RAW
#define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
({ \
+ int _sys_buf[2]; \
register int _a1 asm ("a1"); \
- int _nametmp = name; \
+ register int *_r6 asm ("r6") = _sys_buf; \
+ *_r6 = name; \
LOAD_ARGS_##nr (args) \
- register int _name asm ("ip") = _nametmp; \
- asm volatile ("bl __libc_do_syscall" \
- : "=r" (_a1) \
- : "r" (_name) ASM_ARGS_##nr \
- : "memory", "lr"); \
- _a1; })
+ asm volatile ("str r7, [r6, #4]\n\t" \
+ "ldr r7, [r6]\n\t" \
+ "swi 0 @ syscall " #name "\n\t" \
+ "ldr r7, [r6, #4]" \
+ : "=r" (_a1) \
+ : "r" (_r6) ASM_ARGS_##nr \
+ : "memory"); \
+ _a1; })
#else /* ARM */
#undef INTERNAL_SYSCALL_RAW
#define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
|
