From: Felix Fietkau Date: Tue, 22 Jul 2025 09:58:15 +0000 (+0200) Subject: toolchain/gcc: prevent the use of LDRD/STRD on ARMv5TE X-Git-Url: http://git.openwrt.org/?a=commitdiff_plain;h=c1c11120069b8e04ad4b0c6e815d2e3421944933;p=openwrt%2Fopenwrt.git toolchain/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. This patch was originally added more than 11 years ago in commit b050f87d13b5, but got lost 6 years ago, when gcc 9.1 was added in 88c07c655262. This primarily affects the kirkwood and ixp4xx targets Signed-off-by: Felix Fietkau --- diff --git a/toolchain/gcc/patches-12.x/800-arm_v5te_no_ldrd_strd.patch b/toolchain/gcc/patches-12.x/800-arm_v5te_no_ldrd_strd.patch new file mode 100644 index 0000000000..e83cb1bebb --- /dev/null +++ b/toolchain/gcc/patches-12.x/800-arm_v5te_no_ldrd_strd.patch @@ -0,0 +1,11 @@ +--- a/gcc/config/arm/arm.h ++++ b/gcc/config/arm/arm.h +@@ -165,7 +165,7 @@ emission of floating point pcs attribute + /* Thumb-1 only. */ + #define TARGET_THUMB1_ONLY (TARGET_THUMB1 && !arm_arch_notm) + +-#define TARGET_LDRD (arm_arch5te && ARM_DOUBLEWORD_ALIGN \ ++#define TARGET_LDRD (arm_arch6 && ARM_DOUBLEWORD_ALIGN \ + && !TARGET_THUMB1) + + #define TARGET_CRC32 (arm_arch_crc) diff --git a/toolchain/gcc/patches-13.x/800-arm_v5te_no_ldrd_strd.patch b/toolchain/gcc/patches-13.x/800-arm_v5te_no_ldrd_strd.patch new file mode 100644 index 0000000000..e83cb1bebb --- /dev/null +++ b/toolchain/gcc/patches-13.x/800-arm_v5te_no_ldrd_strd.patch @@ -0,0 +1,11 @@ +--- a/gcc/config/arm/arm.h ++++ b/gcc/config/arm/arm.h +@@ -165,7 +165,7 @@ emission of floating point pcs attribute + /* Thumb-1 only. */ + #define TARGET_THUMB1_ONLY (TARGET_THUMB1 && !arm_arch_notm) + +-#define TARGET_LDRD (arm_arch5te && ARM_DOUBLEWORD_ALIGN \ ++#define TARGET_LDRD (arm_arch6 && ARM_DOUBLEWORD_ALIGN \ + && !TARGET_THUMB1) + + #define TARGET_CRC32 (arm_arch_crc) diff --git a/toolchain/gcc/patches-14.x/800-arm_v5te_no_ldrd_strd.patch b/toolchain/gcc/patches-14.x/800-arm_v5te_no_ldrd_strd.patch new file mode 100644 index 0000000000..e83cb1bebb --- /dev/null +++ b/toolchain/gcc/patches-14.x/800-arm_v5te_no_ldrd_strd.patch @@ -0,0 +1,11 @@ +--- a/gcc/config/arm/arm.h ++++ b/gcc/config/arm/arm.h +@@ -165,7 +165,7 @@ emission of floating point pcs attribute + /* Thumb-1 only. */ + #define TARGET_THUMB1_ONLY (TARGET_THUMB1 && !arm_arch_notm) + +-#define TARGET_LDRD (arm_arch5te && ARM_DOUBLEWORD_ALIGN \ ++#define TARGET_LDRD (arm_arch6 && ARM_DOUBLEWORD_ALIGN \ + && !TARGET_THUMB1) + + #define TARGET_CRC32 (arm_arch_crc) diff --git a/toolchain/gcc/patches-15.x/800-arm_v5te_no_ldrd_strd.patch b/toolchain/gcc/patches-15.x/800-arm_v5te_no_ldrd_strd.patch new file mode 100644 index 0000000000..e83cb1bebb --- /dev/null +++ b/toolchain/gcc/patches-15.x/800-arm_v5te_no_ldrd_strd.patch @@ -0,0 +1,11 @@ +--- a/gcc/config/arm/arm.h ++++ b/gcc/config/arm/arm.h +@@ -165,7 +165,7 @@ emission of floating point pcs attribute + /* Thumb-1 only. */ + #define TARGET_THUMB1_ONLY (TARGET_THUMB1 && !arm_arch_notm) + +-#define TARGET_LDRD (arm_arch5te && ARM_DOUBLEWORD_ALIGN \ ++#define TARGET_LDRD (arm_arch6 && ARM_DOUBLEWORD_ALIGN \ + && !TARGET_THUMB1) + + #define TARGET_CRC32 (arm_arch_crc)