Hello Masahiro, This review is outstanding. Thanks for the time you used to write me this. Il giorno ven 1 set 2023 alle ore 07:32 Masahiro Yamada <masahiroy@xxxxxxxxxx> ha scritto: > > 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 > > > > I will make the necessary updates to v4 based on your analysis. > > 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. > > > > > Understood. In version 4, I will remove all of this and place a new variable, ADDR2LINE, in the top Makefile. I'll remove all this in favour of a ne > > + 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? > > > > > Yes, I can keep the last item I added and avoid the seek. I will make this on the v4. > > +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 > > > > > > > I initiated a conversation with Masami to inquire about the practical utility of these two items. I personally find them useful, but it's possible they may not serve a significant purpose. Therefore, before proceeding with any modifications, I'd like to receive feedback regarding their usefulness. In essence, these two configuration items enable the creation of unique variable names. Since I couldn't identify any other method to ensure their uniqueness except by adding the "__alias__<seqnum>" as seen in my v1 patch, it's important to note that the resulting names may be less meaningful than those for function names. > > +#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? > > > > > You might be giving me too much credit, or perhaps I didn't catch onto your humor. To clarify, what you're witnessing is an error that arose during the debugging process. During my debugging phase, I had a habit of initializing variables. However, when it came time to reset them to NULL, I inadvertently made the wrong adjustment. >From a compiler's perspective, these mistakes yield the same outcome and no error as setting the pointer to NULL, which is why the error went unnoticed. Moving forward, I plan to be more attentive to ensure I produce higher-quality code for my upcoming contributions. > > + 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 thank you
