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authorHauke Mehrtens2026-04-05 11:53:32 +0000
committerHauke Mehrtens2026-06-18 00:27:10 +0000
commit8e7ae1b936eedb086a898a00489b49a9f72bb403 (patch)
tree49b6cd9fed7ca4a2ef9de16921b6ab8acc47f19f
parent9c0c586eedee6b789ca13680349452b02ac6474c (diff)
downloadopenwrt-8e7ae1b936eedb086a898a00489b49a9f72bb403.tar.gz
build: set max-page-size linker flag to match target page size
ELF binaries embed the maximum page size used during linking in the PT_LOAD segment alignment. If this value is larger than the actual system page size, the kernel will still load the binary but wastes memory due to over-alignment. If it is smaller, the binary may fail to load or cause incorrect behavior with features like RELRO. Most architectures use 4KB pages, but loongarch64 uses 16KB pages (CONFIG_PAGE_SIZE_16KB). Explicitly pass -z max-page-size to the linker so that binaries are built with the correct page alignment for the target, avoiding issues with RELRO segment padding and ensuring correct memory mapping on the target system. Before binutils 2.39 RELRO sections were padded to common page size which is 4K on MIPS, with binutils 3.29 the padding was changed to max page size which is 64K on MIPS. With this change we will pad them to 4K again. This reduces the size of user space binaries in OpenWrt. The size of the uncompressed root file system of a mips malta be build decreased by about 20%. old file size: ``` $ du -s build_dir/target-mips_24kc_musl/root-malta/ 15844 build_dir/target-mips_24kc_musl/root-malta/ ``` New file size: ``` $ du -s build_dir/target-mips_24kc_musl/root-malta/ 12564 build_dir/target-mips_24kc_musl/root-malta/ ``` The size of the image did not decrease much because of the strong compression used by OpenWrt. Link: https://github.com/openwrt/openwrt/pull/22800 (cherry picked from commit 04f10eb796dd817d3e03e52d745dc92de735e77a) Link: https://github.com/openwrt/openwrt/pull/23210 Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
-rw-r--r--include/package.mk9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/package.mk b/include/package.mk
index da9fc7d4eb..af594eff0c 100644
--- a/include/package.mk
+++ b/include/package.mk
@@ -62,6 +62,15 @@ ifdef CONFIG_USE_MOLD
endif
endif
+# loongarch64 sets CONFIG_PAGE_SIZE_16KB, all other targets set CONFIG_PAGE_SIZE_4KB only.
+ifeq ($(ARCH),loongarch64)
+ TARGET_CFLAGS += -Wl,-z,max-page-size=16384
+ TARGET_LDFLAGS += -zmax-page-size=16384
+else
+ TARGET_CFLAGS += -Wl,-z,max-page-size=4096
+ TARGET_LDFLAGS += -zmax-page-size=4096
+endif
+
include $(INCLUDE_DIR)/hardening.mk
include $(INCLUDE_DIR)/prereq.mk
include $(INCLUDE_DIR)/unpack.mk