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| author | Felix Fietkau <nbd@openwrt.org> | 2015-10-30 15:20:12 +0000 |
|---|---|---|
| committer | Felix Fietkau <nbd@openwrt.org> | 2015-10-30 15:20:12 +0000 |
| commit | 3bbb92772813c7a955d210f0e82ebdedd3183cec (patch) | |
| tree | cd2af101317782b50e042653366438ecddcea63d | |
| parent | 1cfa2a674757f6ee776436154d2b8d34fb2b1114 (diff) | |
| download | upstream-3bbb92772813c7a955d210f0e82ebdedd3183cec.tar.gz upstream-3bbb92772813c7a955d210f0e82ebdedd3183cec.tar.bz2 upstream-3bbb92772813c7a955d210f0e82ebdedd3183cec.zip | |
build: Allow kernel modules to set build ID debug symbol
This change adds support for specifying a build ID for kernel modules.
This is done by setting PKG_BUILD_ID to a hexadecimal string, which will
then be passed to the kernel linker. In addition, when this flag is set,
the build ID debug symbol (.note.gnu.build-id) will not be stripped from
the kernel module. This symbol is exported in sysfs by the kernel (if
the kernel is compiled with CONFIG_KALLSYMS) and so can be used to
uniquely identify a version of a kernel module in a running kernel. This
is useful for keeping track of different versions of a module when doing
experiments and development.
Modules that specify the build ID will be ~100 bytes larger (depending
on the length of the build ID specified). There is no size difference
for kernel modules that do not set this variable.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
SVN-Revision: 47290
| -rw-r--r-- | include/kernel-defaults.mk | 3 | ||||
| -rw-r--r-- | rules.mk | 3 | ||||
| -rwxr-xr-x | scripts/strip-kmod.sh | 5 |
3 files changed, 8 insertions, 3 deletions
diff --git a/include/kernel-defaults.mk b/include/kernel-defaults.mk index 24d26308b1..d37787a44b 100644 --- a/include/kernel-defaults.mk +++ b/include/kernel-defaults.mk @@ -11,7 +11,8 @@ KERNEL_MAKEOPTS := -C $(LINUX_DIR) \ ARCH="$(LINUX_KARCH)" \ KBUILD_HAVE_NLS=no \ CONFIG_SHELL="$(BASH)" \ - $(if $(findstring c,$(OPENWRT_VERBOSE)),V=1,V='') + $(if $(findstring c,$(OPENWRT_VERBOSE)),V=1,V='') \ + $(if $(PKG_BUILD_ID),LDFLAGS_MODULE=--build-id=0x$(PKG_BUILD_ID)) ifdef CONFIG_STRIP_KERNEL_EXPORTS KERNEL_MAKEOPTS += \ @@ -273,8 +273,9 @@ else STRIP:=$(STAGING_DIR_HOST)/bin/sstrip endif endif - RSTRIP:= \ + RSTRIP= \ export CROSS="$(TARGET_CROSS)" \ + $(if $(PKG_BUILD_ID),KEEP_BUILD_ID=1) \ $(if $(CONFIG_KERNEL_KALLSYMS),NO_RENAME=1) \ $(if $(CONFIG_KERNEL_PROFILING),KEEP_SYMBOLS=1); \ NM="$(TARGET_CROSS)nm" \ diff --git a/scripts/strip-kmod.sh b/scripts/strip-kmod.sh index 13e6b58007..e3f13bee47 100755 --- a/scripts/strip-kmod.sh +++ b/scripts/strip-kmod.sh @@ -18,11 +18,14 @@ else ARGS="-x -G __this_module --strip-unneeded" fi +if [ -z "$KEEP_BUILD_ID" ]; then + ARGS="$ARGS -R .note.gnu.build-id" +fi + ${CROSS}objcopy \ -R .comment \ -R .pdr \ -R .mdebug.abi32 \ - -R .note.gnu.build-id \ -R .gnu.attributes \ -R .reginfo \ $ARGS \ |