On Mon, Aug 28, 2023 at 8:45 PM Alessandro Carminati (Red Hat) <alessandro.carminati@xxxxxxxxx> wrote: > > From: Alessandro Carminati <alessandro.carminati@xxxxxxxxx> > > It is not uncommon for drivers or modules related to similar peripherals > to have symbols with the exact same name. > While this is not a problem for the kernel's binary itself, it becomes an > issue when attempting to trace or probe specific functions using > infrastructure like ftrace or kprobe. > > The tracing subsystem relies on the `nm -n vmlinux` output, which provides > symbol information from the kernel's ELF binary. However, when multiple > symbols share the same name, the standard nm output does not differentiate > between them. This can lead to confusion and difficulty when trying to > probe the intended symbol. > > ~ # cat /proc/kallsyms | grep " name_show" > ffffffff8c4f76d0 t name_show > ffffffff8c9cccb0 t name_show > ffffffff8cb0ac20 t name_show > ffffffff8cc728c0 t name_show > ffffffff8ce0efd0 t name_show > ffffffff8ce126c0 t name_show > ffffffff8ce1dd20 t name_show > ffffffff8ce24e70 t name_show > ffffffff8d1104c0 t name_show > ffffffff8d1fe480 t name_show > > **kas_alias** addresses this challenge by extending the symbol names with > unique suffixes during the kernel build process. > The newly created aliases for these duplicated symbols are unique names > that can be fed to the ftracefs interface. By doing so, it enables > previously unreachable symbols to be probed. > > ~ # cat /proc/kallsyms | grep " name_show" > ffffffff974f76d0 t name_show > ffffffff974f76d0 t name_show__alias__6340 > ffffffff979cccb0 t name_show > ffffffff979cccb0 t name_show__alias__6341 > ffffffff97b0ac20 t name_show > ffffffff97b0ac20 t name_show__alias__6342 > ffffffff97c728c0 t name_show > ffffffff97c728c0 t name_show__alias__6343 > ffffffff97e0efd0 t name_show > ffffffff97e0efd0 t name_show__alias__6344 > ffffffff97e126c0 t name_show > ffffffff97e126c0 t name_show__alias__6345 > ffffffff97e1dd20 t name_show > ffffffff97e1dd20 t name_show__alias__6346 > ffffffff97e24e70 t name_show > ffffffff97e24e70 t name_show__alias__6347 > ffffffff981104c0 t name_show > ffffffff981104c0 t name_show__alias__6348 > ffffffff981fe480 t name_show > ffffffff981fe480 t name_show__alias__6349 > > ~ # echo "p:kprobes/evnt1 name_show__alias__6349" \ > > >/sys/kernel/tracing/kprobe_events > ~ # cat /sys/kernel/tracing/kprobe_events > p:kprobes/evnt1 name_show__alias__6349 > > Changes from v1: > - Integrated changes requested by Masami to exclude symbols with prefixes > "_cfi" and "_pfx". > - Introduced a small framework to handle patterns that need to be excluded > from the alias production. > - Excluded other symbols using the framework. > - Introduced the ability to discriminate between text and data symbols. > - Added two new config symbols in this version: CONFIG_KALLSYMS_ALIAS_DATA, > which allows data for data, and CONFIG_KALLSYMS_ALIAS_DATA_ALL, which > excludes all filters and provides an alias for each duplicated symbol. > > https://lore.kernel.org/all/20230711151925.1092080-1-alessandro.carminati@xxxxxxxxx/ > > Changes from v2: > - Alias tags are created by querying DWARF information from the vmlinux. > - The filename + line number is normalized and appended to the original name. > - The tag begins with '@' to indicate the symbol source. > - Not a change, but worth mentioning, since the alias is added to the existing > list, the old duplicated name is preserved, and the livepatch way of dealing > with duplicates is maintained. > - Acknowledging the existence of scenarios where inlined functions declared in > header files may result in multiple copies due to compiler behavior, though > it is not actionable as it does not pose an operational issue. > - Highlighting a single exception where the same name refers to different > functions: the case of "compat_binfmt_elf.c," which directly includes > "binfmt_elf.c" producing identical function copies in two separate > modules. > > sample from new v3 > > ~ # cat /proc/kallsyms | grep gic_mask_irq > ffffd0b03c04dae4 t gic_mask_irq > ffffd0b03c04dae4 t gic_mask_irq@_drivers_irqchip_irq-gic_c_167 > ffffd0b03c050960 t gic_mask_irq > ffffd0b03c050960 t gic_mask_irq@_drivers_irqchip_irq-gic-v3_c_404 > ~ # > > https://lore.kernel.org/all/20230714150326.1152359-1-alessandro.carminati@xxxxxxxxx/ > > Signed-off-by: Alessandro Carminati (Red Hat) <alessandro.carminati@xxxxxxxxx> > --- > init/Kconfig | 36 ++++ > scripts/Makefile | 4 + > scripts/kas_alias/Makefile | 4 + > scripts/kas_alias/a2l.c | 268 ++++++++++++++++++++++++++++ > scripts/kas_alias/a2l.h | 32 ++++ > scripts/kas_alias/duplicates_list.c | 70 ++++++++ > scripts/kas_alias/duplicates_list.h | 15 ++ > scripts/kas_alias/item_list.c | 230 ++++++++++++++++++++++++ > scripts/kas_alias/item_list.h | 26 +++ > scripts/kas_alias/kas_alias.c | 217 ++++++++++++++++++++++ > scripts/link-vmlinux.sh | 11 +- > 11 files changed, 910 insertions(+), 3 deletions(-) > create mode 100644 scripts/kas_alias/Makefile > create mode 100644 scripts/kas_alias/a2l.c > create mode 100644 scripts/kas_alias/a2l.h > create mode 100644 scripts/kas_alias/duplicates_list.c > create mode 100644 scripts/kas_alias/duplicates_list.h > create mode 100644 scripts/kas_alias/item_list.c > create mode 100644 scripts/kas_alias/item_list.h > create mode 100644 scripts/kas_alias/kas_alias.c > > diff --git a/init/Kconfig b/init/Kconfig > index f7f65af4ee12..bc69fcd9cbc8 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1737,6 +1737,42 @@ config KALLSYMS_BASE_RELATIVE > time constants, and no relocation pass is required at runtime to fix > up the entries based on the runtime load address of the kernel. > > +config KALLSYMS_ALIAS > + bool "Produces alias for duplicated symbols" if EXPERT > + depends on KALLSYMS && (DEBUG_INFO_DWARF4 || DEBUG_INFO_DWARF5) You can simplify this to depends on KALLSYMS && DEBUG_INFO I re-checked the commit log of a66049e2cf0ef166dba5bafdbb3062287fc965ad It says "GCC since ~4.8 has defaulted to DWARF v4 implicitly, and GCC 11 has bumped this to v5" When DEBUG_INFO is enabled, the dwarf version is 4 or 5. Presumably, your code does not work with DEBUG_INFO_SPLIT depends on KALLSYMS && DEBUG_INFO && !DEBUG_INFO_SPLIT > diff --git a/scripts/kas_alias/a2l.c b/scripts/kas_alias/a2l.c > new file mode 100644 > index 000000000000..a9692ac30180 > --- /dev/null > +++ b/scripts/kas_alias/a2l.c > @@ -0,0 +1,268 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <unistd.h> > +#include <sys/types.h> > +#include <sys/wait.h> > +#include <string.h> <string.h> is included twice. I always sort include directives alphabetically to avoid such a mistake. > +#include <stdint.h> > +#include <stdbool.h> > + > +#include "a2l.h" > + > +int addr2line_pid = -1; > +int a2l_in[2]; > +int a2l_out[2]; > +char line[MAX_BUF]; > +char vmlinux_path[MAX_BUF]; > +char addr2line_cmd[MAX_CMD_LEN]; > +FILE *a2l_stdin, *a2l_stdout; > + > +static char *normalize_path(const char *input_path, char *output_path) > +{ > + char *prev_token = NULL; > + char *delimiter = "/"; > + char inbuf[MAX_BUF]; > + char *token; > + char *pos; > + > + memset(inbuf, 0, MAX_BUF); > + *output_path = '\0'; > + strncpy(inbuf, input_path, MAX_BUF); > + if (!input_path || !output_path || strlen(input_path) == 0) > + return NULL; > + > + token = strtok(inbuf, delimiter); > + while (token) { > + if (strcmp(token, "..") == 0 && prev_token) { > + pos = strrchr(output_path, '/'); > + if (pos) > + *pos = '\0'; > + > + } else if (strcmp(token, ".") != 0) { > + strcat(output_path, "/"); > + strcat(output_path, token); > + } > + > + prev_token = token; > + token = strtok(NULL, delimiter); > + } > + > + return output_path; > +} > + > +static void path_of(const char *full_path, char *path) > +{ > + const char *last_slash = strrchr(full_path, '/'); > + size_t path_length; > + char cwd[MAX_BUF]; > + > + if (!last_slash) { > + if (getcwd(cwd, sizeof(cwd))) > + strcpy(path, cwd); > + else > + strcpy(path, "."); > + } else { > + path_length = last_slash - full_path; > + strncpy(path, full_path, path_length); > + path[path_length] = '\0'; > + } > +} > + > +static bool file_exists(const char *file_path) > +{ > + FILE *file; > + > + file = fopen(file_path, "r"); > + if (file) { > + fclose(file); > + return true; > + } > + return false; > +} > + > +int addr2line_init(const char *cmd, const char *vmlinux) > +{ > + if ((!file_exists(cmd)) || (!file_exists(vmlinux))) { > + printf("file not found\n"); > + return 0; > + } > + > + path_of(vmlinux, vmlinux_path); > + if (pipe(a2l_in) == -1) { > + printf("Failed to create pipe\n"); > + return 0; > + } > + > + if (pipe(a2l_out) == -1) { > + printf("Failed to create pipe\n"); > + return 0; > + } > + > + addr2line_pid = fork(); > + if (addr2line_pid == -1) { > + printf("Failed to fork process\n"); > + close(a2l_in[P_READ]); > + close(a2l_in[P_WRITE]); > + close(a2l_out[P_READ]); > + close(a2l_out[P_WRITE]); > + return 0; > + } > + > + if (addr2line_pid == 0) { > + dup2(a2l_in[P_READ], 0); > + dup2(a2l_out[P_WRITE], 1); > + close(a2l_in[P_WRITE]); > + close(a2l_out[P_READ]); > + > + execlp(cmd, cmd, ADDR2LINE_ARGS, vmlinux, NULL); > + > + printf("Failed to execute addr2line command\n"); > + exit(1); > + } else { > + close(a2l_in[P_READ]); > + close(a2l_out[P_WRITE]); > + } > + > + a2l_stdin = fdopen(a2l_in[P_WRITE], "w"); > + if (!a2l_stdin) { > + printf("Failed to open pipe a2l_in\n"); > + return 0; > + } > + > + a2l_stdout = fdopen(a2l_out[P_READ], "r"); > + if (!a2l_stdout) { > + printf("Failed to open pipe a2l_out\n"); > + fclose(a2l_stdin); > + return 0; > + } > + > + return 1; > +} > + > +const char *remove_subdir(const char *home, const char *f_path) > +{ > + int i = 0; > + > + while (*(home + i) == *(f_path + i)) > + i++; > + > + return (strlen(home) != i) ? NULL : f_path + i; > +} > + > +char *addr2line_get_lines(uint64_t address) > +{ > + char buf[MAX_BUF]; > + > + fprintf(a2l_stdin, "%08lx\n", address); > + fflush(a2l_stdin); > + > + if (!fgets(line, sizeof(line), a2l_stdout)) { > + printf("Failed to read lines from addr2line\n"); > + return NULL; > + } > + > + if (!fgets(line, sizeof(line), a2l_stdout)) { > + printf("Failed to read lines from addr2line\n"); > + return NULL; > + } > + > + line[strcspn(line, "\n")] = '\0'; > + strncpy(buf, line, MAX_BUF); > + return normalize_path(buf, line); > +} > + > +int addr2line_cleanup(void) > +{ > + int status; > + > + if (addr2line_pid != -1) { > + kill(addr2line_pid, SIGKILL); > + waitpid(addr2line_pid, &status, 0); > + fclose(a2l_stdin); > + fclose(a2l_stdout); > + addr2line_pid = -1; > + } > + > + return 1; > +} > + > +static char *find_executable(const char *command) > +{ > + char *path_env = getenv("PATH"); > + char *executable_path; > + char *path_copy; > + char *path; > + int n; > + > + if (!path_env) > + return NULL; > + > + path_copy = strdup(path_env); > + if (!path_copy) > + return NULL; > + > + path = strtok(path_copy, ":"); > + while (path) { > + n = snprintf(0, 0, "%s/%s", path, command); > + executable_path = (char *)malloc(n + 1); > + snprintf(executable_path, n + 1, "%s/%s", path, command); > + if (access(executable_path, X_OK) == 0) { > + free(path_copy); > + return executable_path; > + } > + > + path = strtok(NULL, ":"); > + free(executable_path); > + executable_path = NULL; > + } > + > + free(path_copy); > + if (executable_path) > + free(executable_path); > + return NULL; > +} > + > +const char *get_addr2line(int mode) > +{ > + char *buf = ""; > + > + switch (mode) { > + case A2L_CROSS: > + buf = getenv("CROSS_COMPILE"); > + memcpy(addr2line_cmd, buf, strlen(buf)); Dangerous code. It is easy to cause a buffer overrun by setting a long string to CROSS_COMPILE. I am fine with adding ADDR2LINE in the top Makefile. > + case A2L_DEFAULT: > + memcpy(addr2line_cmd + strlen(buf), ADDR2LINE, strlen(ADDR2LINE)); > + buf = find_executable(addr2line_cmd); > + if (buf) { > + memcpy(addr2line_cmd, buf, strlen(buf)); > + free(buf); > + } > + return addr2line_cmd; > + case A2L_LLVM: > + default: > + return NULL; > + } > +} > + > +char *get_vmlinux(char *input) > +{ > + const char *match_string1 = ".syms"; > + const char *match_string2 = ".tmp_vmlinux.kallsyms"; > + char *result = NULL; > + char *match_pos; > + > + match_pos = strstr(input, match_string1); > + if (!match_pos) > + return NULL; > + > + match_pos = strstr(input, match_string2); > + if (!match_pos) > + return NULL; > + > + result = strdup(input); > + match_pos = strstr(result, match_string1); > + *match_pos = '\0'; > + return result; > +} Tedious code to compute the vmlinux name. You can pass vmlinux from command line. > diff --git a/scripts/kas_alias/item_list.c b/scripts/kas_alias/item_list.c > new file mode 100644 > index 000000000000..48f2e525592a > --- /dev/null > +++ b/scripts/kas_alias/item_list.c > @@ -0,0 +1,230 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +#include <stdio.h> > +#include <stdlib.h> > +#include <stdint.h> > +#include <string.h> > +#include <stdbool.h> > +#include <assert.h> > +#include "item_list.h" > + > +#define CHECK_ORDER_BY_ADDRESS(sort_by, current, temp, op) \ > + ((sort_by) == BY_ADDRESS && (current)->addr op (temp)->addr) > +#define CHECK_ORDER_BY_NAME(sort_by, current, temp, op) \ > + ((sort_by) == BY_NAME && strcmp((current)->symb_name, (temp)->symb_name) op 0) > + > +struct item *list_index[96] = {0}; > + > +void build_index(struct item *list) > +{ > + char current_first_letter = ' '; > + struct item *current = list; > + > + while (current) { > + if (current->symb_name[0] != current_first_letter) { > + current_first_letter = current->symb_name[0]; > + list_index[current_first_letter - 32] = current; > + } > + current = current->next; > + } > +} > + > +struct item *add_item(struct item **list, const char *name, char stype, uint64_t addr) > +{ > + struct item *new_item; > + struct item *current; > + > + new_item = malloc(sizeof(struct item)); > + if (!new_item) > + return NULL; > + > + strncpy(new_item->symb_name, name, MAX_NAME_SIZE); > + new_item->symb_name[MAX_NAME_SIZE - 1] = '\0'; > + new_item->addr = addr; > + new_item->stype = stype; > + new_item->next = NULL; > + > + if (!(*list)) { > + *list = new_item; > + } else { > + current = *list; > + while (current->next) > + current = current->next; What is the purpose of the ->next traverse in while() loop? If you remember the last item, you know where the new item should be connected, don't you? > +struct item *merge(struct item *left, struct item *right, int sort_by) > +{ > + struct item *current = NULL; > + struct item *result = NULL; > + > + if (!left) > + return right; > + if (!right) > + return left; > + > + if (sort_by == BY_NAME) { > + if (strcmp(left->symb_name, right->symb_name) <= 0) { > + result = left; > + left = left->next; > + } else { > + result = right; > + right = right->next; > + } > + } else { > + if (sort_by == BY_ADDRESS) { > + if (left->addr <= right->addr) { > + result = left; > + left = left->next; > + } else { > + result = right; > + right = right->next; > + } > + } > + } > + > + current = result; > + > + while (left && right) { > + if (sort_by == BY_NAME) { > + if (strcmp(left->symb_name, right->symb_name) <= 0) { > + current->next = left; > + left = left->next; > + } else { > + current->next = right; > + right = right->next; > + } > + } else { > + if (sort_by == BY_ADDRESS) { > + if (left->addr <= right->addr) { > + current->next = left; > + left = left->next; > + } else { > + current->next = right; > + right = right->next; > + } > + } > + } > + > + current = current->next; > + } > + > + if (left) { > + current->next = left; > + } else { > + if (right) > + current->next = right; > + } > + > + return result; > +} > + > +struct item *merge_sort(struct item *head, int sort_by) Any reason why you did not use qsort() in the C library? One disadvantage of quick sort is that it is not "stable sort". But, your algorithm (sort by name and sort by address) does not keep the order anyway. > diff --git a/scripts/kas_alias/item_list.h b/scripts/kas_alias/item_list.h > new file mode 100644 > index 000000000000..b4891cb088ee > --- /dev/null > +++ b/scripts/kas_alias/item_list.h > @@ -0,0 +1,26 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +#ifndef ITEM_LIST_H > +#define ITEM_LIST_H > +#include <stdint.h> > + > +#define MAX_NAME_SIZE 256 > +#define BY_ADDRESS 1 > +#define BY_NAME 2 > + > +struct item { > + char symb_name[MAX_NAME_SIZE]; > + uint64_t addr; > + char stype; > + struct item *next; > +}; > + > +void build_index(struct item *list); > +struct item *add_item(struct item **list, const char *name, char stype, uint64_t addr); > +void sort_list(struct item **list, int sort_by); > +struct item *merge(struct item *left, struct item *right, int sort_by); > +struct item *merge_sort(struct item *head, int sort_by); > +void sort_list_m(struct item **head, int sort_by); > +int insert_after(struct item *list, const uint64_t search_addr, > + const char *name, uint64_t addr, char stype); > +void free_items(struct item **head); > +#endif > diff --git a/scripts/kas_alias/kas_alias.c b/scripts/kas_alias/kas_alias.c > new file mode 100644 > index 000000000000..532aeb39f851 > --- /dev/null > +++ b/scripts/kas_alias/kas_alias.c > @@ -0,0 +1,217 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +#include <stdio.h> > +#include <stdlib.h> > +#include <stdint.h> > +#include <unistd.h> > +#include <string.h> > +#include <stdbool.h> > +#include <stdarg.h> > +#include <regex.h> > + > +#include "item_list.h" > +#include "duplicates_list.h" > +#include "a2l.h" > + > +#define SYMB_IS_TEXT(s) ((((s)->stype) == 't') || (((s)->stype) == 'T')) > +#define SYMB_IS_DATA(s) ((((s)->stype) == 'b') || (((s)->stype) == 'B') || \ > + (((s)->stype) == 'd') || (((s)->stype) == 'D') || \ > + (((s)->stype) == 'r') || (((s)->stype) == 'R')) > +#ifdef CONFIG_KALLSYMS_ALIAS_DATA Please do not use #ifdef CONFIG_ in host programs. Also, please note include/linux/kconfig.h is not included for host programs, so this #ifdef is always false. You never tested this CONFIG_KALLSYMS_ALIAS_DATA > +#define SYMB_NEEDS_ALIAS(s) (SYMB_IS_TEXT(s) || SYMB_IS_DATA(s)) > +#else > +#define SYMB_NEEDS_ALIAS(s) SYMB_IS_TEXT(s) > +#endif > +#define FNOMATCH 0 > +#define FMATCH 1 > +#define EREGEX 2 > + > +const char *ignore_regex[] = { > + "^__cfi_.*$", // __cfi_ preamble > +#ifndef CONFIG_KALLSYMS_ALIAS_DATA_ALL > + "^_*TRACE_SYSTEM.*$", > + "^__already_done\\.[0-9]+$", // Call a function once data > + "^___tp_str\\.[0-9]+$", > + "^___done\\.[0-9]+$", > + "^__print_once\\.[0-9]+$", > + "^_rs\\.[0-9]+$", > + "^__compound_literal\\.[0-9]+$", > + "^___once_key\\.[0-9]+$", > + "^__func__\\.[0-9]+$", > + "^__msg\\.[0-9]+$", > + "^CSWTCH\\.[0-9]+$", > + "^__flags\\.[0-9]+$", > + "^__wkey.*$", > + "^__mkey.*$", > + "^__key.*$", > +#endif > + "^__pfx_.*$" // NOP-padding > +}; > + > +int suffix_serial; > + > +static inline void verbose_msg(bool verbose, const char *fmt, ...) Meaningless 'inline'. Only 'static' is enough. > +{ > + va_list args; > + > + va_start(args, fmt); > + if (verbose) > + printf(fmt, args); You cannot pass va_list to printf(). The correct code is: vprintf(fmt, args); > + > + va_end(args); > +} verbose_msg() prints the message to stdout. If verbose_msge is enabled, the output file breaks because you redirect both real data and debug messages in this way: scripts/kas_alias/kas_alias <input> > <output> If you implement debug logging, I recommend this: scripts/kas_alias/kas_alias <input> <output> > + > +static void create_suffix(const char *name, char *output_suffix) > +{ > + sprintf(output_suffix, "%s__alias__%d", name, suffix_serial++); > +} > + > +static void create_file_suffix(const char *name, uint64_t address, char *output_suffix, char *cwd) > +{ > + const char *f_path; > + char *buf; > + int i = 0; > + > + buf = addr2line_get_lines(address); > + f_path = remove_subdir(cwd, buf); > + if (f_path) { > + sprintf(output_suffix, "%s@%s", name, f_path); > + while (*(output_suffix + i) != '\0') { > + switch (*(output_suffix + i)) { > + case '/': > + case ':': > + case '.': > + *(output_suffix + i) = '_'; > + break; > + default: > + } > + i++; > + } > + } else { > + create_suffix(name, output_suffix); > + } > +} > + > +static int filter_symbols(char *symbol, const char **ignore_list, int regex_no) > +{ > + regex_t regex; > + int res, i; > + > + for (i = 0; i < regex_no; i++) { > + res = regcomp(®ex, ignore_list[i], REG_EXTENDED); > + if (res) > + return -EREGEX; > + > + res = regexec(®ex, symbol, 0, NULL, 0); > + regfree(®ex); > + switch (res) { > + case 0: > + return FMATCH; > + case REG_NOMATCH: > + break; > + default: > + return -EREGEX; > + } > + } > + > + return FNOMATCH; > +} > + > +int main(int argc, char *argv[]) > +{ > + char t, sym_name[MAX_NAME_SIZE], new_name[MAX_NAME_SIZE + 15]; > + struct duplicate_item *duplicate_iterator; > + struct duplicate_item *duplicate; > + struct item *head = {NULL}; This might be something new I should learn. When I initialize a pointer, I always write like this: struct item *head = NULL; I have never seen this style before: struct item *head = {NULL}; But, the compiler does not warn about it. Could you educate me how it works? > + bool need_2_process = true; > + struct item *last = {NULL}; > + struct item *current; > + int verbose_mode = 0; > + uint64_t address; > + FILE *fp; > + int res; > + > + if (argc < 2 || argc > 3) { > + printf("Usage: %s <nmfile> [-verbose]\n", argv[0]); > + return 1; > + } > + > + if (argc == 3 && strcmp(argv[2], "-verbose") == 0) "-v" or "--verbose" is better (although there is no way to enable it.) Anyway, I only see super-boring messages even with -verbose given. Scanning nm data() Sorting nm data Scanning nm data for duplicates Applying suffixes > + verbose_mode = 1; > + > + verbose_msg(verbose_mode, "Scanning nm data(%s)\n", argv[1]); > + > + fp = fopen(argv[1], "r"); > + if (!fp) { > + printf("Can't open input file.\n"); > + return 1; > + } > + > + if (!addr2line_init(get_addr2line(A2L_DEFAULT), get_vmlinux(argv[1]))) > + return 1; > + > + while (fscanf(fp, "%lx %c %99s\n", &address, &t, sym_name) == 3) { > + if (strstr(sym_name, "@_")) { > + if (verbose_mode && need_2_process) > + printf("Already processed\n"); > + need_2_process = false; > + } > + last = add_item(&last, sym_name, t, address); > + if (!last) { > + printf("Error in allocate memory\n"); > + free_items(&head); > + return 1; > + } > + > + if (!head) > + head = last; > + } > + > + fclose(fp); > + > + if (need_2_process) { > + verbose_msg(verbose_mode, "Sorting nm data\n"); > + sort_list_m(&head, BY_NAME); > + verbose_msg(verbose_mode, "Scanning nm data for duplicates\n"); > + duplicate = find_duplicates(head); > + if (!duplicate) { > + printf("Error in duplicates list\n"); > + return 1; > + } > + > + verbose_msg(verbose_mode, "Applying suffixes\n"); > + build_index(head); > + duplicate_iterator = duplicate; > + while (duplicate_iterator) { > + res = filter_symbols(duplicate_iterator->original_item->symb_name, > + ignore_regex, sizeof(ignore_regex) / > + sizeof(ignore_regex[0])); > + if (res != FMATCH && > + SYMB_NEEDS_ALIAS(duplicate_iterator->original_item)) { > + if (res < 0) > + return 1; > + > + create_file_suffix(duplicate_iterator->original_item->symb_name, > + duplicate_iterator->original_item->addr, > + new_name, vmlinux_path); > + if (!insert_after(head, duplicate_iterator->original_item->addr, > + new_name, duplicate_iterator->original_item->addr, > + duplicate_iterator->original_item->stype)) > + return 1; > + } > + > + duplicate_iterator = duplicate_iterator->next; > + } > + > + sort_list_m(&head, BY_ADDRESS); Do you sort just for finding duplicates? Since you sort the list by name, and then sort by address. It can potentially change the order. [input] 00000000 D foo 00000000 D bar 00000010 D baz [merge sort by name] 00000000 D bar 00000010 D baz 00000000 D foo [merge sort by address = final result] 00000000 D bar 00000000 D foo 00000010 D baz It may not be a big deal, but such a destructive algorithm is frowned. You do not need to sort the list to find duplicates. Another choice is a hashtable of { name : count }. Traversing the list, you can count the number of occurrences. If count >= 2, it is duplicated. The average look-up of a hashtable is O(1). So, the hashtable (or set) algorithm is O(N). Sorting is O(N log N). > diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh > index a432b171be82..cacf60b597ce 100755 > --- a/scripts/link-vmlinux.sh > +++ b/scripts/link-vmlinux.sh > @@ -89,8 +89,9 @@ vmlinux_link() > > ldflags="${ldflags} ${wl}--script=${objtree}/${KBUILD_LDS}" > > - # The kallsyms linking does not need debug symbols included. > - if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then > + # The kallsyms linking does not need debug symbols included, unless the KALLSYMS_ALIAS. > + if [ ! is_enabled CONFIG_KALLSYMS_ALIAS ] && \ I observed this error message: scripts/link-vmlinux.sh: 93: [: is_enabled: unexpected operator The correct code is this: if ! is_enabled CONFIG_KALLSYMS_ALIAS && \ > + [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then > ldflags="${ldflags} ${wl}--strip-debug" > fi > > @@ -161,7 +162,11 @@ kallsyms() > fi > > info KSYMS ${2} > - scripts/kallsyms ${kallsymopt} ${1} > ${2} > + if is_enabled CONFIG_KALLSYMS_ALIAS; then > + ALIAS=".alias" > + scripts/kas_alias/kas_alias ${1} >${1}${ALIAS} > + fi > + scripts/kallsyms ${kallsymopt} ${1}${ALIAS} > ${2} > } > > # Perform one step in kallsyms generation, including temporary linking of > -- > 2.34.1 > -- Best Regards Masahiro Yamada
