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| author | Kees Cook <kees@kernel.org> | 2024-11-17 03:38:13 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-01-09 13:28:41 +0100 |
| commit | 2461ffdc772523f7bc2e1e67028c6e559d63a70b (patch) | |
| tree | b03271abd385bcb008f48f235424c5755c64cc3a /lib | |
| parent | 002668bfd4162259282965cb6d36b401effd33ff (diff) | |
| download | linux-2461ffdc772523f7bc2e1e67028c6e559d63a70b.tar.gz linux-2461ffdc772523f7bc2e1e67028c6e559d63a70b.tar.bz2 linux-2461ffdc772523f7bc2e1e67028c6e559d63a70b.zip | |
lib: stackinit: hide never-taken branch from compiler
[ Upstream commit 5c3793604f91123bf49bc792ce697a0bef4c173c ]
The never-taken branch leads to an invalid bounds condition, which is by
design. To avoid the unwanted warning from the compiler, hide the
variable from the optimizer.
../lib/stackinit_kunit.c: In function 'do_nothing_u16_zero':
../lib/stackinit_kunit.c:51:49: error: array subscript 1 is outside array bounds of 'u16[0]' {aka 'short unsigned int[]'} [-Werror=array-bounds=]
51 | #define DO_NOTHING_RETURN_SCALAR(ptr) *(ptr)
| ^~~~~~
../lib/stackinit_kunit.c:219:24: note: in expansion of macro 'DO_NOTHING_RETURN_SCALAR'
219 | return DO_NOTHING_RETURN_ ## which(ptr + 1); \
| ^~~~~~~~~~~~~~~~~~
Link: https://lkml.kernel.org/r/20241117113813.work.735-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/test_stackinit.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/lib/test_stackinit.c b/lib/test_stackinit.c index a3c74e6a21ff..56653c6a2a61 100644 --- a/lib/test_stackinit.c +++ b/lib/test_stackinit.c @@ -259,6 +259,7 @@ static noinline __init int test_ ## name (void) \ static noinline __init DO_NOTHING_TYPE_ ## which(var_type) \ do_nothing_ ## name(var_type *ptr) \ { \ + OPTIMIZER_HIDE_VAR(ptr); \ /* Will always be true, but compiler doesn't know. */ \ if ((unsigned long)ptr > 0x2) \ return DO_NOTHING_RETURN_ ## which(ptr); \ |