Merge tag 'core-headers-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel...

[linux.git] / include / linux / compiler.h

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 59f7194fdf08758ebdb50840255e162f0f909eb8..6810d80acb0b9cff2cfe41357ce3fd3a656b5e02 100644 (file)
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -120,65 +120,12 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 /* Annotate a C jump table to allow objtool to follow the code flow */
 #define __annotate_jump_table __section(.rodata..c_jump_table)
 
-#ifdef CONFIG_DEBUG_ENTRY
-/* Begin/end of an instrumentation safe region */
-#define instrumentation_begin() ({                                     \
-       asm volatile("%c0: nop\n\t"                                             \
-                    ".pushsection .discard.instr_begin\n\t"            \
-                    ".long %c0b - .\n\t"                               \
-                    ".popsection\n\t" : : "i" (__COUNTER__));          \
-})
-
-/*
- * Because instrumentation_{begin,end}() can nest, objtool validation considers
- * _begin() a +1 and _end() a -1 and computes a sum over the instructions.
- * When the value is greater than 0, we consider instrumentation allowed.
- *
- * There is a problem with code like:
- *
- * noinstr void foo()
- * {
- *     instrumentation_begin();
- *     ...
- *     if (cond) {
- *             instrumentation_begin();
- *             ...
- *             instrumentation_end();
- *     }
- *     bar();
- *     instrumentation_end();
- * }
- *
- * If instrumentation_end() would be an empty label, like all the other
- * annotations, the inner _end(), which is at the end of a conditional block,
- * would land on the instruction after the block.
- *
- * If we then consider the sum of the !cond path, we'll see that the call to
- * bar() is with a 0-value, even though, we meant it to happen with a positive
- * value.
- *
- * To avoid this, have _end() be a NOP instruction, this ensures it will be
- * part of the condition block and does not escape.
- */
-#define instrumentation_end() ({                                       \
-       asm volatile("%c0: nop\n\t"                                     \
-                    ".pushsection .discard.instr_end\n\t"              \
-                    ".long %c0b - .\n\t"                               \
-                    ".popsection\n\t" : : "i" (__COUNTER__));          \
-})
-#endif /* CONFIG_DEBUG_ENTRY */
-
 #else
 #define annotate_reachable()
 #define annotate_unreachable()
 #define __annotate_jump_table
 #endif
 
-#ifndef instrumentation_begin
-#define instrumentation_begin()                do { } while(0)
-#define instrumentation_end()          do { } while(0)
-#endif
-
 #ifndef ASM_UNREACHABLE
 # define ASM_UNREACHABLE
 #endif