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| author | Kees Cook <keescook@chromium.org> | 2021-06-16 13:18:23 -0700 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2021-06-28 11:18:28 +0200 |
| commit | c74d3c182ab4a3db6c3c2a6c4b3c8b9a7f1feb1a (patch) | |
| tree | 1286621ca4c6759d5d9ec1e78af01f72c474c228 /arch/s390/kernel | |
| parent | e5e1bdf0bca8cd16ad39ed2febf6f689d9c07586 (diff) | |
| download | linux-c74d3c182ab4a3db6c3c2a6c4b3c8b9a7f1feb1a.tar.bz2 | |
s390/speculation: Use statically initialized const for instructions
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
confusing the checks when using a static const source.
Move the static const array into a variable so the compiler can perform
appropriate bounds checking.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210616201823.1245603-1-keescook@chromium.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
| -rw-r--r-- | arch/s390/kernel/nospec-branch.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index 2c5c3756644b..250e4dbf653c 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -99,6 +99,7 @@ early_param("spectre_v2", spectre_v2_setup_early); static void __init_or_module __nospec_revert(s32 *start, s32 *end) { enum { BRCL_EXPOLINE, BRASL_EXPOLINE } type; + static const u8 branch[] = { 0x47, 0x00, 0x07, 0x00 }; u8 *instr, *thunk, *br; u8 insnbuf[6]; s32 *epo; @@ -128,7 +129,7 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end) if ((br[0] & 0xbf) != 0x07 || (br[1] & 0xf0) != 0xf0) continue; - memcpy(insnbuf + 2, (char[]) { 0x47, 0x00, 0x07, 0x00 }, 4); + memcpy(insnbuf + 2, branch, sizeof(branch)); switch (type) { case BRCL_EXPOLINE: insnbuf[0] = br[0]; |