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| author |   Nathan Chancellor <nathan@kernel.org> | 2021-02-04 18:32:57 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-05 11:03:47 -0800 |
| commit | 28abcc963149e06d956d95a18a85f4ba26af746f (patch) | |
| tree | 3f34955346c312dfd06509be3ebd3e4634cf05ff | |
| parent | kasan: make addr_has_metadata() return true for valid addresses (diff) | |
| download | linux-dev-28abcc963149e06d956d95a18a85f4ba26af746f.tar.xz linux-dev-28abcc963149e06d956d95a18a85f4ba26af746f.zip | |
ubsan: implement __ubsan_handle_alignment_assumption
When building ARCH=mips 32r2el_defconfig with CONFIG_UBSAN_ALIGNMENT:
ld.lld: error: undefined symbol: __ubsan_handle_alignment_assumption
referenced by slab.h:557 (include/linux/slab.h:557)
main.o:(do_initcalls) in archive init/built-in.a
referenced by slab.h:448 (include/linux/slab.h:448)
do_mounts_rd.o:(rd_load_image) in archive init/built-in.a
referenced by slab.h:448 (include/linux/slab.h:448)
do_mounts_rd.o:(identify_ramdisk_image) in archive init/built-in.a
referenced 1579 more times
Implement this for the kernel based on LLVM's
handleAlignmentAssumptionImpl because the kernel is not linked against
the compiler runtime.
Link: https://github.com/ClangBuiltLinux/linux/issues/1245
Link: https://github.com/llvm/llvm-project/blob/llvmorg-11.0.1/compiler-rt/lib/ubsan/ubsan_handlers.cpp#L151-L190
Link: https://lkml.kernel.org/r/20210127224451.2587372-1-nathan@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | lib/ubsan.c | 31 | ||||
| -rw-r--r-- | lib/ubsan.h | 6 |
2 files changed, 37 insertions, 0 deletions
diff --git a/lib/ubsan.c b/lib/ubsan.c index 3e3352f3d0da..bec38c64d6a6 100644 --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -427,3 +427,34 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val) ubsan_epilogue(); } EXPORT_SYMBOL(__ubsan_handle_load_invalid_value); + +void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, + unsigned long align, + unsigned long offset); +void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, + unsigned long align, + unsigned long offset) +{ + struct alignment_assumption_data *data = _data; + unsigned long real_ptr; + + if (suppress_report(&data->location)) + return; + + ubsan_prologue(&data->location, "alignment-assumption"); + + if (offset) + pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed", + align, offset, data->type->type_name); + else + pr_err("assumption of %lu byte alignment for pointer of type %s failed", + align, data->type->type_name); + + real_ptr = ptr - offset; + pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes", + offset ? "offset " : "", BIT(real_ptr ? __ffs(real_ptr) : 0), + real_ptr & (align - 1)); + + ubsan_epilogue(); +} +EXPORT_SYMBOL(__ubsan_handle_alignment_assumption); diff --git a/lib/ubsan.h b/lib/ubsan.h index 7b56c09473a9..9a0b71c5ff9f 100644 --- a/lib/ubsan.h +++ b/lib/ubsan.h @@ -78,6 +78,12 @@ struct invalid_value_data { struct type_descriptor *type; }; +struct alignment_assumption_data { + struct source_location location; + struct source_location assumption_location; + struct type_descriptor *type; +}; + #if defined(CONFIG_ARCH_SUPPORTS_INT128) typedef __int128 s_max; typedef unsigned __int128 u_max; |