by Nick Desaulniers

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On Fri, Mar 12, 2021 at 02:41:32PM -0800, Nick Desaulniers wrote:
> 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
> Suggested-by: Nathan Chancellor <[email protected]>
> Signed-off-by: Nick Desaulniers <[email protected]>

Reviewed-by: Nathan Chancellor <[email protected]>

> ---
> For an easier time reviewing this series, reviewers may want to apply
> these patches, then check the overall diff with `git diff origin/HEAD`.
>
> kernel/gcov/Kconfig | 1 +
> kernel/gcov/clang.c | 85 ---------------------------------------------
> 2 files changed, 1 insertion(+), 85 deletions(-)
>
> diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
> index f62de2dea8a3..58f87a3092f3 100644
> --- a/kernel/gcov/Kconfig
> +++ b/kernel/gcov/Kconfig
> @@ -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
> diff --git a/kernel/gcov/clang.c b/kernel/gcov/clang.c
> index 8743150db2ac..14de5644b5cc 100644
> --- a/kernel/gcov/clang.c
> +++ b/kernel/gcov/clang.c
> @@ -75,9 +75,6 @@ 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;
> @@ -107,16 +104,6 @@ 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;
> @@ -124,29 +111,7 @@ void llvm_gcda_start_file(const char *orig_filename, u32 version, u32 checksum)
> 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);
> -}
> -EXPORT_SYMBOL(llvm_gcda_emit_function);
> -#else
> void llvm_gcda_emit_function(u32 ident, u32 func_checksum,
> u8 use_extra_checksum, u32 cfg_checksum)
> {
> @@ -163,7 +128,6 @@ void llvm_gcda_emit_function(u32 ident, u32 func_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)
> {
> @@ -326,7 +290,6 @@ 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 */
> @@ -335,47 +298,15 @@ static struct gcov_fn_info *gcov_fn_info_dup(struct gcov_fn_info *fn)
> 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 = vmalloc(cv_size);
> - 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 */
> - 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
> @@ -416,21 +347,6 @@ 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;
> @@ -443,7 +359,6 @@ void gcov_info_free(struct gcov_info *info)
> kfree(info->filename);
> kfree(info);
> }
> -#endif
>
> #define ITER_STRIDE PAGE_SIZE
>
> --
> 2.31.0.rc2.261.g7f71774620-goog
>