Commit 60bcf728 authored by Nick Desaulniers's avatar Nick Desaulniers Committed by Linus Torvalds
Browse files

gcov: fix clang-11+ support 

LLVM changed the expected function signatures for llvm_gcda_start_file()
and llvm_gcda_emit_function() in the clang-11 release.  Users of
clang-11 or newer may have noticed their kernels failing to boot due to
a panic when enabling CONFIG_GCOV_KERNEL=y +CONFIG_GCOV_PROFILE_ALL=y.
Fix up the function signatures so calling these functions doesn't panic
the kernel.

Link: https://reviews.llvm.org/rGcdd683b516d147925212724b09ec6fb792a40041
Link: https://reviews.llvm.org/rG13a633b438b6500ecad9e4f936ebadf3411d0f44
Link: https://lkml.kernel.org/r/20210312224132.3413602-2-ndesaulniers@google.com


Signed-off-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Reported-by: default avatarPrasad Sodagudi <psodagud@quicinc.com>
Suggested-by: default avatarNathan Chancellor <nathan@kernel.org>
Reviewed-by: default avatarFangrui Song <maskray@google.com>
Tested-by: default avatarNathan Chancellor <nathan@kernel.org>
Acked-by: default avatarPeter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: default avatarNathan Chancellor <nathan@kernel.org>
Cc: <stable@vger.kernel.org>	[5.4+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 95d44a47

kernel/gcov/clang.c

+69 −0
Original line number Diff line number Diff line
@@ -75,7 +75,9 @@ struct gcov_fn_info { 


	u32 num_counters;

	u64 *counters;

#if CONFIG_CLANG_VERSION < 110000

	const char *function_name;

#endif

};



static struct gcov_info *current_info;
@@ -105,6 +107,7 @@ void llvm_gcov_init(llvm_gcov_callback writeout, llvm_gcov_callback flush) 
}

EXPORT_SYMBOL(llvm_gcov_init);



#if CONFIG_CLANG_VERSION < 110000

void llvm_gcda_start_file(const char *orig_filename, const char version[4],

		u32 checksum)

{
@@ -113,7 +116,17 @@ void llvm_gcda_start_file(const char *orig_filename, const char version[4], 
	current_info->checksum = checksum;

}

EXPORT_SYMBOL(llvm_gcda_start_file);

#else

void llvm_gcda_start_file(const char *orig_filename, u32 version, u32 checksum)

{

	current_info->filename = orig_filename;

	current_info->version = version;

	current_info->checksum = checksum;

}

EXPORT_SYMBOL(llvm_gcda_start_file);

#endif



#if CONFIG_CLANG_VERSION < 110000

void llvm_gcda_emit_function(u32 ident, const char *function_name,

		u32 func_checksum, u8 use_extra_checksum, u32 cfg_checksum)

{
@@ -133,6 +146,24 @@ void llvm_gcda_emit_function(u32 ident, const char *function_name, 
	list_add_tail(&info->head, &current_info->functions);

}

EXPORT_SYMBOL(llvm_gcda_emit_function);

#else

void llvm_gcda_emit_function(u32 ident, u32 func_checksum,

		u8 use_extra_checksum, u32 cfg_checksum)

{

	struct gcov_fn_info *info = kzalloc(sizeof(*info), GFP_KERNEL);



	if (!info)

		return;



	INIT_LIST_HEAD(&info->head);

	info->ident = ident;

	info->checksum = func_checksum;

	info->use_extra_checksum = use_extra_checksum;

	info->cfg_checksum = cfg_checksum;

	list_add_tail(&info->head, &current_info->functions);

}

EXPORT_SYMBOL(llvm_gcda_emit_function);

#endif



void llvm_gcda_emit_arcs(u32 num_counters, u64 *counters)

{
@@ -295,6 +326,7 @@ void gcov_info_add(struct gcov_info *dst, struct gcov_info *src) 
	}

}



#if CONFIG_CLANG_VERSION < 110000

static struct gcov_fn_info *gcov_fn_info_dup(struct gcov_fn_info *fn)

{

	size_t cv_size; /* counter values size */
@@ -322,6 +354,28 @@ static struct gcov_fn_info *gcov_fn_info_dup(struct gcov_fn_info *fn) 
	kfree(fn_dup);

	return NULL;

}

#else

static struct gcov_fn_info *gcov_fn_info_dup(struct gcov_fn_info *fn)

{

	size_t cv_size; /* counter values size */

	struct gcov_fn_info *fn_dup = kmemdup(fn, sizeof(*fn),

			GFP_KERNEL);

	if (!fn_dup)

		return NULL;

	INIT_LIST_HEAD(&fn_dup->head);



	cv_size = fn->num_counters * sizeof(fn->counters[0]);

	fn_dup->counters = vmalloc(cv_size);

	if (!fn_dup->counters) {

		kfree(fn_dup);

		return NULL;

	}



	memcpy(fn_dup->counters, fn->counters, cv_size);



	return fn_dup;

}

#endif



/**

 * gcov_info_dup - duplicate profiling data set
@@ -362,6 +416,7 @@ struct gcov_info *gcov_info_dup(struct gcov_info *info) 
 * gcov_info_free - release memory for profiling data set duplicate

 * @info: profiling data set duplicate to free

 */

#if CONFIG_CLANG_VERSION < 110000

void gcov_info_free(struct gcov_info *info)

{

	struct gcov_fn_info *fn, *tmp;
@@ -375,6 +430,20 @@ void gcov_info_free(struct gcov_info *info) 
	kfree(info->filename);

	kfree(info);

}

#else

void gcov_info_free(struct gcov_info *info)

{

	struct gcov_fn_info *fn, *tmp;



	list_for_each_entry_safe(fn, tmp, &info->functions, head) {

		vfree(fn->counters);

		list_del(&fn->head);

		kfree(fn);

	}

	kfree(info->filename);

	kfree(info);

}

#endif



#define ITER_STRIDE	PAGE_SIZE