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gcov: clang: drop support for clang-10 and older
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LLVM changed the expected function signatures for llvm_gcda_start_file()
and llvm_gcda_emit_function() in the clang-11 release.  Drop the older
implementations and require folks to upgrade their compiler if they're
interested in GCOV support.

Link: https://reviews.llvm.org/rGcdd683b516d147925212724b09ec6fb792a40041
Link: https://reviews.llvm.org/rG13a633b438b6500ecad9e4f936ebadf3411d0f44
Link: https://lkml.kernel.org/r/20210312224132.3413602-3-ndesaulniers@google.com
Link: https://lkml.kernel.org/r/20210413183113.2977432-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Cc: Prasad Sodagudi <psodagud@quicinc.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@nickdesaulniers @torvalds
nickdesaulniers authored and torvalds committed May 7, 2021
1 parent 1391efa commit 9b472e8
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Showing 2 changed files with 1 addition and 103 deletions.
1 change: 1 addition & 0 deletions kernel/gcov/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@ menu "GCOV-based kernel profiling"
config GCOV_KERNEL
bool "Enable gcov-based kernel profiling"
depends on DEBUG_FS
depends on !CC_IS_CLANG || CLANG_VERSION >= 110000
select CONSTRUCTORS
default n
help
Expand Down
103 changes: 0 additions & 103 deletions kernel/gcov/clang.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -69,16 +69,10 @@ struct gcov_fn_info {

u32 ident;
u32 checksum;
#if CONFIG_CLANG_VERSION < 110000
u8 use_extra_checksum;
#endif
u32 cfg_checksum;

u32 num_counters;
u64 *counters;
#if CONFIG_CLANG_VERSION < 110000
const char *function_name;
#endif
};

static struct gcov_info *current_info;
Expand Down Expand Up @@ -108,45 +102,14 @@ 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)
{
current_info->filename = orig_filename;
memcpy(&current_info->version, version, sizeof(current_info->version));
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)
{
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;
if (function_name)
info->function_name = kstrdup(function_name, GFP_KERNEL);

list_add_tail(&info->head, &current_info->functions);
}
#else
void llvm_gcda_emit_function(u32 ident, u32 func_checksum, u32 cfg_checksum)
{
struct gcov_fn_info *info = kzalloc(sizeof(*info), GFP_KERNEL);
Expand All @@ -160,7 +123,6 @@ void llvm_gcda_emit_function(u32 ident, u32 func_checksum, u32 cfg_checksum)
info->cfg_checksum = cfg_checksum;
list_add_tail(&info->head, &current_info->functions);
}
#endif
EXPORT_SYMBOL(llvm_gcda_emit_function);

void llvm_gcda_emit_arcs(u32 num_counters, u64 *counters)
Expand Down Expand Up @@ -291,16 +253,8 @@ int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
!list_is_last(&fn_ptr2->head, &info2->functions)) {
if (fn_ptr1->checksum != fn_ptr2->checksum)
return false;
#if CONFIG_CLANG_VERSION < 110000
if (fn_ptr1->use_extra_checksum != fn_ptr2->use_extra_checksum)
return false;
if (fn_ptr1->use_extra_checksum &&
fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum)
return false;
#else
if (fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum)
return false;
#endif
fn_ptr1 = list_next_entry(fn_ptr1, head);
fn_ptr2 = list_next_entry(fn_ptr2, head);
}
Expand Down Expand Up @@ -329,35 +283,6 @@ 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 */
struct gcov_fn_info *fn_dup = kmemdup(fn, sizeof(*fn), GFP_KERNEL);

if (!fn_dup)
return NULL;
INIT_LIST_HEAD(&fn_dup->head);

fn_dup->function_name = kstrdup(fn->function_name, GFP_KERNEL);
if (!fn_dup->function_name)
goto err_name;

cv_size = fn->num_counters * sizeof(fn->counters[0]);
fn_dup->counters = kvmalloc(cv_size, GFP_KERNEL);
if (!fn_dup->counters)
goto err_counters;
memcpy(fn_dup->counters, fn->counters, cv_size);

return fn_dup;

err_counters:
kfree(fn_dup->function_name);
err_name:
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 */
Expand All @@ -378,7 +303,6 @@ static struct gcov_fn_info *gcov_fn_info_dup(struct gcov_fn_info *fn)

return fn_dup;
}
#endif

/**
* gcov_info_dup - duplicate profiling data set
Expand Down Expand Up @@ -419,21 +343,6 @@ 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;

list_for_each_entry_safe(fn, tmp, &info->functions, head) {
kfree(fn->function_name);
vfree(fn->counters);
list_del(&fn->head);
kfree(fn);
}
kfree(info->filename);
kfree(info);
}
#else
void gcov_info_free(struct gcov_info *info)
{
struct gcov_fn_info *fn, *tmp;
Expand All @@ -446,7 +355,6 @@ void gcov_info_free(struct gcov_info *info)
kfree(info->filename);
kfree(info);
}
#endif

/**
* convert_to_gcda - convert profiling data set to gcda file format
Expand All @@ -469,21 +377,10 @@ size_t convert_to_gcda(char *buffer, struct gcov_info *info)
u32 i;

pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION);
#if CONFIG_CLANG_VERSION < 110000
pos += store_gcov_u32(buffer, pos,
fi_ptr->use_extra_checksum ? 3 : 2);
#else
pos += store_gcov_u32(buffer, pos, 3);
#endif
pos += store_gcov_u32(buffer, pos, fi_ptr->ident);
pos += store_gcov_u32(buffer, pos, fi_ptr->checksum);
#if CONFIG_CLANG_VERSION < 110000
if (fi_ptr->use_extra_checksum)
pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
#else
pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum);
#endif

pos += store_gcov_u32(buffer, pos, GCOV_TAG_COUNTER_BASE);
pos += store_gcov_u32(buffer, pos, fi_ptr->num_counters * 2);
for (i = 0; i < fi_ptr->num_counters; i++)
Expand Down

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