gcc: prevent the use of LDRD/STRD on ARMv5TE
authorFelix Fietkau <nbd@openwrt.org>
Wed, 19 Feb 2014 19:20:10 +0000 (19:20 +0000)
committerFelix Fietkau <nbd@openwrt.org>
Wed, 19 Feb 2014 19:20:10 +0000 (19:20 +0000)
commit252046eff72548f61b834548683a17ff576b835d
treee4a32fad556b3957e5f2f9175dc5d5950382bd62
parenta28075c234e136de2c393e00401d9203b59f4970
gcc: prevent the use of LDRD/STRD on ARMv5TE

These instructions are for 64-bit load/store. On ARMv5TE, the CPU
requires addresses to be aligned to 64-bit. When misaligned, behavior is
undefined (effectively either loads the same word twice on LDRD, or
corrupts surrounding memory on STRD).

On ARMv6 and newer, unaligned access is safe.

Removing these instructions for ARMv5TE is necessary, because GCC
ignores alignment information in pointers and does unsafe optimizations
that have shown up as bugs in various places.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
SVN-Revision: 39638
toolchain/gcc/patches/4.6-linaro/800-arm_v5te_no_ldrd_strd.patch [new file with mode: 0644]
toolchain/gcc/patches/4.8-linaro/800-arm_v5te_no_ldrd_strd.patch [new file with mode: 0644]
toolchain/gcc/patches/4.8.0/800-arm_v5te_no_ldrd_strd.patch [new file with mode: 0644]