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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-28 09:42:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-28 09:42:47 -0700
commita358505d8af3ab43763e1b49549619528783d2bf (patch)
tree9486032ab6cfad055f0cffabbf0edc48fce77c52 /include
parent719fdd32921fb7e3208db8832d32ae1c2d68900f (diff)
parent2c92d787cc9fad57d05c96bd117782183768258a (diff)
Merge tag 'x86_entry_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 entry fixes from Borislav Petkov: "This is the x86/entry urgent pile which has accumulated since the merge window. It is not the smallest but considering the almost complete entry core rewrite, the amount of fixes to follow is somewhat higher than usual, which is to be expected. Peter Zijlstra says: 'These patches address a number of instrumentation issues that were found after the x86/entry overhaul. When combined with rcu/urgent and objtool/urgent, these patches make UBSAN/KASAN/KCSAN happy again. Part of making this all work is bumping the minimum GCC version for KASAN builds to gcc-8.3, the reason for this is that the __no_sanitize_address function attribute is broken in GCC releases before that. No known GCC version has a working __no_sanitize_undefined, however because the only noinstr violation that results from this happens when an UB is found, we treat it like WARN. That is, we allow it to violate the noinstr rules in order to get the warning out'" * tag 'x86_entry_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry: Fix #UD vs WARN more x86/entry: Increase entry_stack size to a full page x86/entry: Fixup bad_iret vs noinstr objtool: Don't consider vmlinux a C-file kasan: Fix required compiler version compiler_attributes.h: Support no_sanitize_undefined check with GCC 4 x86/entry, bug: Comment the instrumentation_begin() usage for WARN() x86/entry, ubsan, objtool: Whitelist __ubsan_handle_*() x86/entry, cpumask: Provide non-instrumented variant of cpu_is_offline() compiler_types.h: Add __no_sanitize_{address,undefined} to noinstr kasan: Bump required compiler version x86, kcsan: Add __no_kcsan to noinstr kcsan: Remove __no_kcsan_or_inline x86, kcsan: Remove __no_kcsan_or_inline usage
Diffstat (limited to 'include')
-rw-r--r--include/linux/compiler-clang.h8
-rw-r--r--include/linux/compiler-gcc.h6
-rw-r--r--include/linux/compiler_attributes.h1
-rw-r--r--include/linux/compiler_types.h14
4 files changed, 21 insertions, 8 deletions
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index ee37256ec8bd..5e55302e3bf6 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -33,6 +33,14 @@
#define __no_sanitize_thread
#endif
+#if __has_feature(undefined_behavior_sanitizer)
+/* GCC does not have __SANITIZE_UNDEFINED__ */
+#define __no_sanitize_undefined \
+ __attribute__((no_sanitize("undefined")))
+#else
+#define __no_sanitize_undefined
+#endif
+
/*
* Not all versions of clang implement the the type-generic versions
* of the builtin overflow checkers. Fortunately, clang implements
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 7dd4e0349ef3..1c74464c80c6 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -150,6 +150,12 @@
#define __no_sanitize_thread
#endif
+#if __has_attribute(__no_sanitize_undefined__)
+#define __no_sanitize_undefined __attribute__((no_sanitize_undefined))
+#else
+#define __no_sanitize_undefined
+#endif
+
#if GCC_VERSION >= 50100
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
#endif
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
index cdf016596659..c8f03d2969df 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -40,6 +40,7 @@
# define __GCC4_has_attribute___noclone__ 1
# define __GCC4_has_attribute___nonstring__ 0
# define __GCC4_has_attribute___no_sanitize_address__ (__GNUC_MINOR__ >= 8)
+# define __GCC4_has_attribute___no_sanitize_undefined__ (__GNUC_MINOR__ >= 9)
# define __GCC4_has_attribute___fallthrough__ 0
#endif
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index e368384445b6..c3bf7710f69a 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -118,10 +118,6 @@ struct ftrace_likely_data {
#define notrace __attribute__((__no_instrument_function__))
#endif
-/* Section for code which can't be instrumented at all */
-#define noinstr \
- noinline notrace __attribute((__section__(".noinstr.text")))
-
/*
* it doesn't make sense on ARM (currently the only user of __naked)
* to trace naked functions because then mcount is called without
@@ -193,16 +189,18 @@ struct ftrace_likely_data {
#define __no_kcsan __no_sanitize_thread
#ifdef __SANITIZE_THREAD__
-# define __no_kcsan_or_inline __no_kcsan notrace __maybe_unused
-# define __no_sanitize_or_inline __no_kcsan_or_inline
-#else
-# define __no_kcsan_or_inline __always_inline
+# define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused
#endif
#ifndef __no_sanitize_or_inline
#define __no_sanitize_or_inline __always_inline
#endif
+/* Section for code which can't be instrumented at all */
+#define noinstr \
+ noinline notrace __attribute((__section__(".noinstr.text"))) \
+ __no_kcsan __no_sanitize_address
+
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */