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| author | Johannes Berg <johannes.berg@intel.com> | 2021-02-04 18:32:28 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-05 11:03:47 -0800 |
| commit | 55b6f763d8bcb5546997933105d66d3e6b080e6a (patch) | |
| tree | 2f432429dce1cf4b659426112db5f2bbd3ca71f1 | |
| parent | 4f6ec8602341e97b364e4e0d41a1ed08148f5e98 (diff) | |
| download | dm-user-55b6f763d8bcb5546997933105d66d3e6b080e6a.tar.gz | |
init/gcov: allow CONFIG_CONSTRUCTORS on UML to fix module gcov
On ARCH=um, loading a module doesn't result in its constructors getting
called, which breaks module gcov since the debugfs files are never
registered. On the other hand, in-kernel constructors have already been
called by the dynamic linker, so we can't call them again.
Get out of this conundrum by allowing CONFIG_CONSTRUCTORS to be
selected, but avoiding the in-kernel constructor calls.
Also remove the "if !UML" from GCOV selecting CONSTRUCTORS now, since we
really do want CONSTRUCTORS, just not kernel binary ones.
Link: https://lkml.kernel.org/r/20210120172041.c246a2cac2fb.I1358f584b76f1898373adfed77f4462c8705b736@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | init/Kconfig | 1 | ||||
| -rw-r--r-- | init/main.c | 8 | ||||
| -rw-r--r-- | kernel/gcov/Kconfig | 2 |
3 files changed, 8 insertions, 3 deletions
diff --git a/init/Kconfig b/init/Kconfig index b77c60f8b963d4..29ad6832502880 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -76,7 +76,6 @@ config CC_HAS_ASM_INLINE config CONSTRUCTORS bool - depends on !UML config IRQ_WORK bool diff --git a/init/main.c b/init/main.c index c68d784376ca10..a626e78dbf0611 100644 --- a/init/main.c +++ b/init/main.c @@ -1066,7 +1066,13 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) /* Call all constructor functions linked into the kernel. */ static void __init do_ctors(void) { -#ifdef CONFIG_CONSTRUCTORS +/* + * For UML, the constructors have already been called by the + * normal setup code as it's just a normal ELF binary, so we + * cannot do it again - but we do need CONFIG_CONSTRUCTORS + * even on UML for modules. + */ +#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; for (; fn < (ctor_fn_t *) __ctors_end; fn++) diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig index 3110c77230c7f7..f62de2dea8a317 100644 --- a/kernel/gcov/Kconfig +++ b/kernel/gcov/Kconfig @@ -4,7 +4,7 @@ menu "GCOV-based kernel profiling" config GCOV_KERNEL bool "Enable gcov-based kernel profiling" depends on DEBUG_FS - select CONSTRUCTORS if !UML + select CONSTRUCTORS default n help This option enables gcov-based code profiling (e.g. for code coverage |