| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2019 Google, Inc. |
| * modified from kernel/gcov/gcc_4_7.c |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * |
| * LLVM uses profiling data that's deliberately similar to GCC, but has a |
| * very different way of exporting that data. LLVM calls llvm_gcov_init() once |
| * per module, and provides a couple of callbacks that we can use to ask for |
| * more data. |
| * |
| * We care about the "writeout" callback, which in turn calls back into |
| * compiler-rt/this module to dump all the gathered coverage data to disk: |
| * |
| * llvm_gcda_start_file() |
| * llvm_gcda_emit_function() |
| * llvm_gcda_emit_arcs() |
| * llvm_gcda_emit_function() |
| * llvm_gcda_emit_arcs() |
| * [... repeats for each function ...] |
| * llvm_gcda_summary_info() |
| * llvm_gcda_end_file() |
| * |
| * This design is much more stateless and unstructured than gcc's, and is |
| * intended to run at process exit. This forces us to keep some local state |
| * about which module we're dealing with at the moment. On the other hand, it |
| * also means we don't depend as much on how LLVM represents profiling data |
| * internally. |
| * |
| * See LLVM's lib/Transforms/Instrumentation/GCOVProfiling.cpp for more |
| * details on how this works, particularly GCOVProfiler::emitProfileArcs(), |
| * GCOVProfiler::insertCounterWriteout(), and |
| * GCOVProfiler::insertFlush(). |
| */ |
| |
| #define pr_fmt(fmt) "gcov: " fmt |
| |
| #include <linux/kernel.h> |
| #include <linux/list.h> |
| #include <linux/printk.h> |
| #include <linux/ratelimit.h> |
| #include <linux/seq_file.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include "gcov.h" |
| |
| typedef void (*llvm_gcov_callback)(void); |
| |
| struct gcov_info { |
| struct list_head head; |
| |
| const char *filename; |
| unsigned int version; |
| u32 checksum; |
| |
| struct list_head functions; |
| }; |
| |
| struct gcov_fn_info { |
| struct list_head head; |
| |
| u32 ident; |
| u32 checksum; |
| u8 use_extra_checksum; |
| u32 cfg_checksum; |
| |
| u32 num_counters; |
| u64 *counters; |
| #if CONFIG_CLANG_VERSION < 110000 |
| const char *function_name; |
| #endif |
| }; |
| |
| static struct gcov_info *current_info; |
| |
| static LIST_HEAD(clang_gcov_list); |
| |
| void llvm_gcov_init(llvm_gcov_callback writeout, llvm_gcov_callback flush) |
| { |
| struct gcov_info *info = kzalloc(sizeof(*info), GFP_KERNEL); |
| |
| if (!info) |
| return; |
| |
| INIT_LIST_HEAD(&info->head); |
| INIT_LIST_HEAD(&info->functions); |
| |
| mutex_lock(&gcov_lock); |
| |
| list_add_tail(&info->head, &clang_gcov_list); |
| current_info = info; |
| writeout(); |
| current_info = NULL; |
| if (gcov_events_enabled) |
| gcov_event(GCOV_ADD, info); |
| |
| mutex_unlock(&gcov_lock); |
| } |
| 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(¤t_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, ¤t_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, ¤t_info->functions); |
| } |
| EXPORT_SYMBOL(llvm_gcda_emit_function); |
| #endif |
| |
| void llvm_gcda_emit_arcs(u32 num_counters, u64 *counters) |
| { |
| struct gcov_fn_info *info = list_last_entry(¤t_info->functions, |
| struct gcov_fn_info, head); |
| |
| info->num_counters = num_counters; |
| info->counters = counters; |
| } |
| EXPORT_SYMBOL(llvm_gcda_emit_arcs); |
| |
| void llvm_gcda_summary_info(void) |
| { |
| } |
| EXPORT_SYMBOL(llvm_gcda_summary_info); |
| |
| void llvm_gcda_end_file(void) |
| { |
| } |
| EXPORT_SYMBOL(llvm_gcda_end_file); |
| |
| /** |
| * gcov_info_filename - return info filename |
| * @info: profiling data set |
| */ |
| const char *gcov_info_filename(struct gcov_info *info) |
| { |
| return info->filename; |
| } |
| |
| /** |
| * gcov_info_version - return info version |
| * @info: profiling data set |
| */ |
| unsigned int gcov_info_version(struct gcov_info *info) |
| { |
| return info->version; |
| } |
| |
| /** |
| * gcov_info_next - return next profiling data set |
| * @info: profiling data set |
| * |
| * Returns next gcov_info following @info or first gcov_info in the chain if |
| * @info is %NULL. |
| */ |
| struct gcov_info *gcov_info_next(struct gcov_info *info) |
| { |
| if (!info) |
| return list_first_entry_or_null(&clang_gcov_list, |
| struct gcov_info, head); |
| if (list_is_last(&info->head, &clang_gcov_list)) |
| return NULL; |
| return list_next_entry(info, head); |
| } |
| |
| /** |
| * gcov_info_link - link/add profiling data set to the list |
| * @info: profiling data set |
| */ |
| void gcov_info_link(struct gcov_info *info) |
| { |
| list_add_tail(&info->head, &clang_gcov_list); |
| } |
| |
| /** |
| * gcov_info_unlink - unlink/remove profiling data set from the list |
| * @prev: previous profiling data set |
| * @info: profiling data set |
| */ |
| void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info) |
| { |
| /* Generic code unlinks while iterating. */ |
| __list_del_entry(&info->head); |
| } |
| |
| /** |
| * gcov_info_within_module - check if a profiling data set belongs to a module |
| * @info: profiling data set |
| * @mod: module |
| * |
| * Returns true if profiling data belongs module, false otherwise. |
| */ |
| bool gcov_info_within_module(struct gcov_info *info, struct module *mod) |
| { |
| return within_module((unsigned long)info->filename, mod); |
| } |
| |
| /* Symbolic links to be created for each profiling data file. */ |
| const struct gcov_link gcov_link[] = { |
| { OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */ |
| { 0, NULL}, |
| }; |
| |
| /** |
| * gcov_info_reset - reset profiling data to zero |
| * @info: profiling data set |
| */ |
| void gcov_info_reset(struct gcov_info *info) |
| { |
| struct gcov_fn_info *fn; |
| |
| list_for_each_entry(fn, &info->functions, head) |
| memset(fn->counters, 0, |
| sizeof(fn->counters[0]) * fn->num_counters); |
| } |
| |
| /** |
| * gcov_info_is_compatible - check if profiling data can be added |
| * @info1: first profiling data set |
| * @info2: second profiling data set |
| * |
| * Returns non-zero if profiling data can be added, zero otherwise. |
| */ |
| int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2) |
| { |
| struct gcov_fn_info *fn_ptr1 = list_first_entry_or_null( |
| &info1->functions, struct gcov_fn_info, head); |
| struct gcov_fn_info *fn_ptr2 = list_first_entry_or_null( |
| &info2->functions, struct gcov_fn_info, head); |
| |
| if (info1->checksum != info2->checksum) |
| return false; |
| if (!fn_ptr1) |
| return fn_ptr1 == fn_ptr2; |
| while (!list_is_last(&fn_ptr1->head, &info1->functions) && |
| !list_is_last(&fn_ptr2->head, &info2->functions)) { |
| if (fn_ptr1->checksum != fn_ptr2->checksum) |
| return false; |
| 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; |
| fn_ptr1 = list_next_entry(fn_ptr1, head); |
| fn_ptr2 = list_next_entry(fn_ptr2, head); |
| } |
| return list_is_last(&fn_ptr1->head, &info1->functions) && |
| list_is_last(&fn_ptr2->head, &info2->functions); |
| } |
| |
| /** |
| * gcov_info_add - add up profiling data |
| * @dest: profiling data set to which data is added |
| * @source: profiling data set which is added |
| * |
| * Adds profiling counts of @source to @dest. |
| */ |
| void gcov_info_add(struct gcov_info *dst, struct gcov_info *src) |
| { |
| struct gcov_fn_info *dfn_ptr; |
| struct gcov_fn_info *sfn_ptr = list_first_entry_or_null(&src->functions, |
| struct gcov_fn_info, head); |
| |
| list_for_each_entry(dfn_ptr, &dst->functions, head) { |
| u32 i; |
| |
| for (i = 0; i < sfn_ptr->num_counters; i++) |
| dfn_ptr->counters[i] += sfn_ptr->counters[i]; |
| } |
| } |
| |
| #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 = 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 |
| * @info: profiling data set to duplicate |
| * |
| * Return newly allocated duplicate on success, %NULL on error. |
| */ |
| struct gcov_info *gcov_info_dup(struct gcov_info *info) |
| { |
| struct gcov_info *dup; |
| struct gcov_fn_info *fn; |
| |
| dup = kmemdup(info, sizeof(*dup), GFP_KERNEL); |
| if (!dup) |
| return NULL; |
| INIT_LIST_HEAD(&dup->head); |
| INIT_LIST_HEAD(&dup->functions); |
| dup->filename = kstrdup(info->filename, GFP_KERNEL); |
| if (!dup->filename) |
| goto err; |
| |
| list_for_each_entry(fn, &info->functions, head) { |
| struct gcov_fn_info *fn_dup = gcov_fn_info_dup(fn); |
| |
| if (!fn_dup) |
| goto err; |
| list_add_tail(&fn_dup->head, &dup->functions); |
| } |
| |
| return dup; |
| |
| err: |
| gcov_info_free(dup); |
| return NULL; |
| } |
| |
| /** |
| * 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; |
| |
| 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 |
| |
| /** |
| * struct gcov_iterator - specifies current file position in logical records |
| * @info: associated profiling data |
| * @buffer: buffer containing file data |
| * @size: size of buffer |
| * @pos: current position in file |
| */ |
| struct gcov_iterator { |
| struct gcov_info *info; |
| void *buffer; |
| size_t size; |
| loff_t pos; |
| }; |
| |
| /** |
| * store_gcov_u32 - store 32 bit number in gcov format to buffer |
| * @buffer: target buffer or NULL |
| * @off: offset into the buffer |
| * @v: value to be stored |
| * |
| * Number format defined by gcc: numbers are recorded in the 32 bit |
| * unsigned binary form of the endianness of the machine generating the |
| * file. Returns the number of bytes stored. If @buffer is %NULL, doesn't |
| * store anything. |
| */ |
| static size_t store_gcov_u32(void *buffer, size_t off, u32 v) |
| { |
| u32 *data; |
| |
| if (buffer) { |
| data = buffer + off; |
| *data = v; |
| } |
| |
| return sizeof(*data); |
| } |
| |
| /** |
| * store_gcov_u64 - store 64 bit number in gcov format to buffer |
| * @buffer: target buffer or NULL |
| * @off: offset into the buffer |
| * @v: value to be stored |
| * |
| * Number format defined by gcc: numbers are recorded in the 32 bit |
| * unsigned binary form of the endianness of the machine generating the |
| * file. 64 bit numbers are stored as two 32 bit numbers, the low part |
| * first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store |
| * anything. |
| */ |
| static size_t store_gcov_u64(void *buffer, size_t off, u64 v) |
| { |
| u32 *data; |
| |
| if (buffer) { |
| data = buffer + off; |
| |
| data[0] = (v & 0xffffffffUL); |
| data[1] = (v >> 32); |
| } |
| |
| return sizeof(*data) * 2; |
| } |
| |
| /** |
| * convert_to_gcda - convert profiling data set to gcda file format |
| * @buffer: the buffer to store file data or %NULL if no data should be stored |
| * @info: profiling data set to be converted |
| * |
| * Returns the number of bytes that were/would have been stored into the buffer. |
| */ |
| static size_t convert_to_gcda(char *buffer, struct gcov_info *info) |
| { |
| struct gcov_fn_info *fi_ptr; |
| size_t pos = 0; |
| |
| /* File header. */ |
| pos += store_gcov_u32(buffer, pos, GCOV_DATA_MAGIC); |
| pos += store_gcov_u32(buffer, pos, info->version); |
| pos += store_gcov_u32(buffer, pos, info->checksum); |
| |
| list_for_each_entry(fi_ptr, &info->functions, head) { |
| u32 i; |
| u32 len = 2; |
| |
| if (fi_ptr->use_extra_checksum) |
| len++; |
| |
| pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION); |
| pos += store_gcov_u32(buffer, pos, len); |
| pos += store_gcov_u32(buffer, pos, fi_ptr->ident); |
| pos += store_gcov_u32(buffer, pos, fi_ptr->checksum); |
| if (fi_ptr->use_extra_checksum) |
| pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum); |
| |
| 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++) |
| pos += store_gcov_u64(buffer, pos, fi_ptr->counters[i]); |
| } |
| |
| return pos; |
| } |
| |
| /** |
| * gcov_iter_new - allocate and initialize profiling data iterator |
| * @info: profiling data set to be iterated |
| * |
| * Return file iterator on success, %NULL otherwise. |
| */ |
| struct gcov_iterator *gcov_iter_new(struct gcov_info *info) |
| { |
| struct gcov_iterator *iter; |
| |
| iter = kzalloc(sizeof(struct gcov_iterator), GFP_KERNEL); |
| if (!iter) |
| goto err_free; |
| |
| iter->info = info; |
| /* Dry-run to get the actual buffer size. */ |
| iter->size = convert_to_gcda(NULL, info); |
| iter->buffer = vmalloc(iter->size); |
| if (!iter->buffer) |
| goto err_free; |
| |
| convert_to_gcda(iter->buffer, info); |
| |
| return iter; |
| |
| err_free: |
| kfree(iter); |
| return NULL; |
| } |
| |
| |
| /** |
| * gcov_iter_get_info - return profiling data set for given file iterator |
| * @iter: file iterator |
| */ |
| void gcov_iter_free(struct gcov_iterator *iter) |
| { |
| vfree(iter->buffer); |
| kfree(iter); |
| } |
| |
| /** |
| * gcov_iter_get_info - return profiling data set for given file iterator |
| * @iter: file iterator |
| */ |
| struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter) |
| { |
| return iter->info; |
| } |
| |
| /** |
| * gcov_iter_start - reset file iterator to starting position |
| * @iter: file iterator |
| */ |
| void gcov_iter_start(struct gcov_iterator *iter) |
| { |
| iter->pos = 0; |
| } |
| |
| /** |
| * gcov_iter_next - advance file iterator to next logical record |
| * @iter: file iterator |
| * |
| * Return zero if new position is valid, non-zero if iterator has reached end. |
| */ |
| int gcov_iter_next(struct gcov_iterator *iter) |
| { |
| if (iter->pos < iter->size) |
| iter->pos += ITER_STRIDE; |
| |
| if (iter->pos >= iter->size) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| /** |
| * gcov_iter_write - write data for current pos to seq_file |
| * @iter: file iterator |
| * @seq: seq_file handle |
| * |
| * Return zero on success, non-zero otherwise. |
| */ |
| int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq) |
| { |
| size_t len; |
| |
| if (iter->pos >= iter->size) |
| return -EINVAL; |
| |
| len = ITER_STRIDE; |
| if (iter->pos + len > iter->size) |
| len = iter->size - iter->pos; |
| |
| seq_write(seq, iter->buffer + iter->pos, len); |
| |
| return 0; |
| } |