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| author | Sami Tolvanen <samitolvanen@google.com> | 2020-04-13 16:10:13 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-02-23 12:46:57 -0800 |
| commit | b1a1a1a09b4606d41723a426110382d2077c26fb (patch) | |
| tree | 4c6672f8aa90443585f2ceb4cb4e65425d800c6a /scripts/link-vmlinux.sh | |
| parent | 41425ebe20245c99b44d6ba0f017be9bfc28414f (diff) | |
| download | linux-b1a1a1a09b4606d41723a426110382d2077c26fb.tar.gz linux-b1a1a1a09b4606d41723a426110382d2077c26fb.tar.bz2 linux-b1a1a1a09b4606d41723a426110382d2077c26fb.zip | |
kbuild: lto: postpone objtool
With LTO, LLVM bitcode won't be compiled into native code until
modpost_link, or modfinal for modules. This change postpones calls
to objtool until after these steps, and moves objtool_args to
Makefile.lib, so the arguments can be reused in Makefile.modfinal.
As we didn't have objects to process earlier, we use --duplicate
when processing vmlinux.o. This change also disables unreachable
instruction warnings with LTO to avoid warnings about the int3
padding between functions.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'scripts/link-vmlinux.sh')
| -rwxr-xr-x | scripts/link-vmlinux.sh | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 18aed761f9c0..3b261b0f74f0 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -103,14 +103,36 @@ modpost_link() objtool_link() { + local objtoolcmd; local objtoolopt; + if [ "${CONFIG_LTO_CLANG} ${CONFIG_STACK_VALIDATION}" = "y y" ]; then + # Don't perform vmlinux validation unless explicitly requested, + # but run objtool on vmlinux.o now that we have an object file. + if [ -n "${CONFIG_UNWINDER_ORC}" ]; then + objtoolcmd="orc generate" + fi + + objtoolopt="${objtoolopt} --duplicate" + + if [ -n "${CONFIG_FTRACE_MCOUNT_USE_OBJTOOL}" ]; then + objtoolopt="${objtoolopt} --mcount" + fi + fi + if [ -n "${CONFIG_VMLINUX_VALIDATION}" ]; then - objtoolopt="check --vmlinux --noinstr" + objtoolopt="${objtoolopt} --noinstr" + fi + + if [ -n "${objtoolopt}" ]; then + if [ -z "${objtoolcmd}" ]; then + objtoolcmd="check" + fi + objtoolopt="${objtoolopt} --vmlinux" if [ -z "${CONFIG_FRAME_POINTER}" ]; then objtoolopt="${objtoolopt} --no-fp" fi - if [ -n "${CONFIG_GCOV_KERNEL}" ]; then + if [ -n "${CONFIG_GCOV_KERNEL}" ] || [ -n "${CONFIG_LTO_CLANG}" ]; then objtoolopt="${objtoolopt} --no-unreachable" fi if [ -n "${CONFIG_RETPOLINE}" ]; then @@ -120,7 +142,7 @@ objtool_link() objtoolopt="${objtoolopt} --uaccess" fi info OBJTOOL ${1} - tools/objtool/objtool ${objtoolopt} ${1} + tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1} fi } |