mirrors/poky
1
0
Fork 0
mirror of https://git.yoctoproject.org/poky synced 2026-05-08 05:09:24 +00:00
Code Issues Projects Releases Wiki Activity

musl: use a more specific fix for ARM thumb + frame pointers

Browse Source 
When compiling for Thumb or Thumb2, frame pointers _must_ be disabled
since the Thumb frame pointer in r7 clashes with musl's use of inline
asm to make syscalls (where r7 is used for the syscall NR).

In most cases, frame pointers will be disabled automatically due to
the optimisation level, but appending an explicit -fomit-frame-pointer
to CFLAGS handles cases where optimisation is set to -O0 or frame
pointers have been enabled by -fno-omit-frame-pointer earlier in
CFLAGS, etc.

Note that this limitation applies both to gcc and clang, the only
difference between the two being that where gcc aborts with an error
about reusing r7, clang apparently silently generates broken code:

  https://bugs.llvm.org/show_bug.cgi?id=34165

(From OE-Core rev: d7580cd7792982fd9e98086e4edc490635e9adca)

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Andre McCurdy
2017-10-09 09:00:35 -07:00
committed by Richard Purdie
parent 48fee62075
commit 65458b6e83
1 changed files with 7 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
meta/recipes-core/musl/musl_git.bb
+7 -1
View File
@@ -28,7 +28,13 @@ export CROSS_COMPILE="${TARGET_PREFIX}"
LDFLAGS += "-Wl,-soname,libc.so"
ARM_INSTRUCTION_SET_toolchain-clang = "arm"
# When compiling for Thumb or Thumb2, frame pointers _must_ be disabled since the
# Thumb frame pointer in r7 clashes with musl's use of inline asm to make syscalls
# (where r7 is used for the syscall NR). In most cases, frame pointers will be
# disabled automatically due to the optimisation level, but append an explicit
# -fomit-frame-pointer to handle cases where optimisation is set to -O0 or frame
# pointers have been enabled by -fno-omit-frame-pointer earlier in CFLAGS, etc.
CFLAGS_append_arm = " ${@bb.utils.contains('TUNE_CCARGS', '-mthumb', '-fomit-frame-pointer', '', d)}"
CONFIGUREOPTS = " \
--prefix=${prefix} \