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| author | Peter Zijlstra <peterz@infradead.org> | 2021-12-04 14:43:44 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-12-09 13:32:25 +0100 |
| commit | e463a09af2f0677b9485a7e8e4e70b396b2ffb6f (patch) | |
| tree | 169cdec1cc953df3619ae2e08e662784211fbc24 /scripts | |
| parent | 26c44b776dba4ac692a0bf5a3836feb8a63fea6b (diff) | |
| download | lwn-e463a09af2f0677b9485a7e8e4e70b396b2ffb6f.tar.gz lwn-e463a09af2f0677b9485a7e8e4e70b396b2ffb6f.zip | |
x86: Add straight-line-speculation mitigation
Make use of an upcoming GCC feature to mitigate
straight-line-speculation for x86:
https://gcc.gnu.org/g:53a643f8568067d7700a9f2facc8ba39974973d3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952
https://bugs.llvm.org/show_bug.cgi?id=52323
It's built tested on x86_64-allyesconfig using GCC-12 and GCC-11.
Maintenance overhead of this should be fairly low due to objtool
validation.
Size overhead of all these additional int3 instructions comes to:
text data bss dec hex filename
22267751 6933356 2011368 31212475 1dc43bb defconfig-build/vmlinux
22804126 6933356 1470696 31208178 1dc32f2 defconfig-build/vmlinux.sls
Or roughly 2.4% additional text.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134908.140103474@infradead.org
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/Makefile.build | 3 | ||||
| -rwxr-xr-x | scripts/link-vmlinux.sh | 3 |
2 files changed, 5 insertions, 1 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 78656b527fe5..a4b89b757287 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -234,7 +234,8 @@ objtool_args = \ $(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\ $(if $(CONFIG_RETPOLINE), --retpoline) \ $(if $(CONFIG_X86_SMAP), --uaccess) \ - $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ + $(if $(CONFIG_SLS), --sls) cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@) cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 5cdd9bc5c385..9716f285e404 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -139,6 +139,9 @@ objtool_link() if [ -n "${CONFIG_X86_SMAP}" ]; then objtoolopt="${objtoolopt} --uaccess" fi + if [ -n "${CONFIG_SLS}" ]; then + objtoolopt="${objtoolopt} --sls" + fi info OBJTOOL ${1} tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1} fi |