The patch titled
Subject: lib/dynamic_debug.c: use address-of operator on section symbols
has been added to the -mm tree. Its filename is
dynamic_debug-use-address-of-operator-on-section-symbols.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/dynamic_debug-use-address-of-operator-on-section-symbols.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/dynamic_debug-use-address-of-operator-on-section-symbols.patch
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------------------------------------------------------
From: Nathan Chancellor <natechancellor@xxxxxxxxx>
Subject: lib/dynamic_debug.c: use address-of operator on section symbols
Clang warns:
../lib/dynamic_debug.c:1034:24: warning: array comparison always
evaluates to false [-Wtautological-compare]
if (__start___verbose == __stop___verbose) {
^
1 warning generated.
These are not true arrays, they are linker defined symbols, which are just
addresses. Using the address of operator silences the warning and does
not change the resulting assembly with either clang/ld.lld or gcc/ld
(tested with diff + objdump -Dr).
Link: https://github.com/ClangBuiltLinux/linux/issues/894
Link: http://lkml.kernel.org/r/20200220051320.10739-1-natechancellor@xxxxxxxxx
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Acked-by: Jason Baron <jbaron@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/dynamic_debug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/lib/dynamic_debug.c~dynamic_debug-use-address-of-operator-on-section-symbols
+++ a/lib/dynamic_debug.c
@@ -1013,7 +1013,7 @@ static int __init dynamic_debug_init(voi
int n = 0, entries = 0, modct = 0;
int verbose_bytes = 0;
- if (__start___verbose == __stop___verbose) {
+ if (&__start___verbose == &__stop___verbose) {
pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
return 1;
}
_
Patches currently in -mm which might be from natechancellor@xxxxxxxxx are
mm-kmemleak-use-address-of-operator-on-section-symbols.patch
kernel-extable-use-address-of-operator-on-section-symbols.patch
dynamic_debug-use-address-of-operator-on-section-symbols.patch
