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authorPeter Zijlstra <peterz@infradead.org>2019-10-21 15:11:49 +0200
committerIngo Molnar <mingo@kernel.org>2019-10-28 10:43:00 +0100
commit9a50dcaf0416a43e1fe411dc61a99c8333c90119 (patch)
tree5910dbf5fd26d3fa435cd76e482691ed1055cae3 /tools/objtool
parent0f42c1ad44d437f75b840b572376fd538fbb9643 (diff)
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ubsan, x86: Annotate and allow __ubsan_handle_shift_out_of_bounds() in uaccess regions
The new check_zeroed_user() function uses variable shifts inside of a user_access_begin()/user_access_end() section and that results in GCC emitting __ubsan_handle_shift_out_of_bounds() calls, even though through value range analysis it would be able to see that the UB in question is impossible. Annotate and whitelist this UBSAN function; continued use of user_access_begin()/user_access_end() will undoubtedly result in further uses of function. Reported-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: cyphar@cyphar.com Cc: keescook@chromium.org Cc: linux@rasmusvillemoes.dk Fixes: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper") Link: https://lkml.kernel.org/r/20191021131149.GA19358@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/objtool')
-rw-r--r--tools/objtool/check.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 044c9a3cb247..f53d3c515cdc 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -481,6 +481,7 @@ static const char *uaccess_safe_builtin[] = {
"ubsan_type_mismatch_common",
"__ubsan_handle_type_mismatch",
"__ubsan_handle_type_mismatch_v1",
+ "__ubsan_handle_shift_out_of_bounds",
/* misc */
"csum_partial_copy_generic",
"__memcpy_mcsafe",