Hi Alessandro, Thanks for your update! On Mon, 28 Aug 2023 08:04:23 +0000 "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 Could you also update the sample output in the patch description? And I can not see this line information but a serial number aliases, is there any way to enable this file-name aliases? (LLVM is not supported?) I think we'd better to have a new CONFIG_KALLSYMS_ALIAS_SRCLINE and clarify what is required. > ~ # > > 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) > + help > + 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. > + > + This option 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 ftrace sysfs interface. By doing so, it > + enables previously unreachable symbols to be probed. > + > +config CONFIG_KALLSYMS_ALIAS_DATA You don't need 'CONFIG_' prefix here. > + bool "Produces alias also for data" > + depends on KALLSYMS_ALIAS > + help > + Sometimes it can be useful to refer to data. In live patch scenarios, > + you may find yourself needing to use symbols that are shared with > + other functions. Since symbols face the same issue as functions, this > + option allows you to create aliases for data as well. > + > +config CONFIG_KALLSYMS_ALIAS_DATA_ALL > + bool "Removes all filter when producing data alias" > + depends on CONFIG_KALLSYMS_ALIAS_DATA > + help > + When selecting data aliases, not all symbols are included in the set > + This is because many symbols are unlikely to be used. If you choose > + to have an alias for all data symbols, be aware that it will > + significantly increase the size. > + > + If unsure, say N. > + > # end of the "standard kernel features (expert users)" menu > > # syscall, maps, verifier > diff --git a/scripts/Makefile b/scripts/Makefile > index 32b6ba722728..65fafe17cfe5 100644 > --- a/scripts/Makefile > +++ b/scripts/Makefile > @@ -49,3 +49,7 @@ subdir-$(CONFIG_SECURITY_SELINUX) += selinux > > # Let clean descend into subdirs > subdir- += basic dtc gdb kconfig mod > + > +# KALLSyms alias > +subdir-$(CONFIG_KALLSYMS_ALIAS) += kas_alias > + > diff --git a/scripts/kas_alias/Makefile b/scripts/kas_alias/Makefile > new file mode 100644 > index 000000000000..e1fde69232b4 > --- /dev/null > +++ b/scripts/kas_alias/Makefile > @@ -0,0 +1,4 @@ > +# SPDX-License-Identifier: GPL-2.0 > +hostprogs-always-$(CONFIG_KALLSYMS_ALIAS) += kas_alias > + > +kas_alias-objs := duplicates_list.o item_list.o kas_alias.o a2l.o > 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> > +#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; > + } nit: mis-indentation? > + > + 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; nit: mis-indentation? > + } > + > + 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)); > + 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; > +} > diff --git a/scripts/kas_alias/a2l.h b/scripts/kas_alias/a2l.h > new file mode 100644 > index 000000000000..ca6419229dde > --- /dev/null > +++ b/scripts/kas_alias/a2l.h > @@ -0,0 +1,32 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +#ifndef A2L_H > +#define A2L_H > +#include <stdint.h> > + > +#define ADDR2LINE "addr2line" > +#define ADDR2LINE_ARGS "-fe" > +//#define VMLINUX "vmlinux" Nit: this should be removed if it is not used. > +#define MAX_BUF 4096 > +#define MAX_CMD_LEN 256 > +#define P_READ 0 > +#define P_WRITE 1 > +#define A2L_DEFAULT 1 > +#define A2L_CROSS 2 > +#define A2L_LLVM 3 > +#define A2L_MAKE_VALUE 2 > + > +extern int addr2line_pid; > +extern int a2l_in[2]; > +extern int a2l_out[2]; > +extern char line[MAX_BUF]; > +extern char vmlinux_path[MAX_BUF]; > +extern char addr2line_cmd[MAX_CMD_LEN]; > + > +int addr2line_init(const char *cmd, const char *vmlinux); > +char *addr2line_get_lines(uint64_t address); > +int addr2line_cleanup(void); > +const char *remove_subdir(const char *home, const char *f_path); > +const char *get_addr2line(int mode); > +char *get_vmlinux(char *input); > + > +#endif > diff --git a/scripts/kas_alias/duplicates_list.c b/scripts/kas_alias/duplicates_list.c > new file mode 100644 > index 000000000000..e7a3d2917937 > --- /dev/null > +++ b/scripts/kas_alias/duplicates_list.c > @@ -0,0 +1,70 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +#include <stdint.h> > +#include <stdio.h> > +#include <string.h> > +#include <stdlib.h> > +#include <stdbool.h> > + > +#include "item_list.h" > +#include "duplicates_list.h" > + /* The item list must be sorted. */ I think we can find the duplicated symbol without sorting the list, but such implementation level optimization will be done later. > +struct duplicate_item *find_duplicates(struct item *list) > +{ > + struct duplicate_item *current_duplicate = NULL; > + struct duplicate_item *duplicates = NULL; > + struct duplicate_item *new_duplicate; > + struct item *current_item = list; > + bool prev_was_duplicate = false; > + struct item *prev_item = NULL; > + > + while (current_item) { > + if ((prev_item && (strcmp(current_item->symb_name, prev_item->symb_name) == 0)) || > + prev_was_duplicate) { > + if (!duplicates) { > + duplicates = malloc(sizeof(struct duplicate_item)); > + if (!duplicates) > + return NULL; > + > + duplicates->original_item = prev_item; > + duplicates->next = NULL; > + current_duplicate = duplicates; > + } else { > + new_duplicate = malloc(sizeof(struct duplicate_item)); > + if (!new_duplicate) { > + free_duplicates(&duplicates); > + return NULL; > + } > + > + new_duplicate->original_item = prev_item; > + new_duplicate->next = NULL; > + current_duplicate->next = new_duplicate; > + current_duplicate = new_duplicate; > + > + if ((strcmp(current_item->symb_name, prev_item->symb_name) != 0) && > + (prev_was_duplicate)) > + prev_was_duplicate = false; > + else > + prev_was_duplicate = true; > + } > + } > + > + prev_item = current_item; > + current_item = current_item->next; > + } > + > + return duplicates; > +} > + > +void free_duplicates(struct duplicate_item **duplicates) > +{ > + struct duplicate_item *duplicates_iterator = *duplicates; > + struct duplicate_item *app; > + > + while (duplicates_iterator) { > + app = duplicates_iterator; > + duplicates_iterator = duplicates_iterator->next; > + free(app); > + } > + > + *duplicates = NULL; > +} > diff --git a/scripts/kas_alias/duplicates_list.h b/scripts/kas_alias/duplicates_list.h > new file mode 100644 > index 000000000000..76aa73e584bc > --- /dev/null > +++ b/scripts/kas_alias/duplicates_list.h > @@ -0,0 +1,15 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +#ifndef DUPLICATES_LIST_H > +#define DUPLICATES_LIST_H > + > +#include "item_list.h" > + > +struct duplicate_item { > + struct item *original_item; > + struct duplicate_item *next; > +}; > + > +struct duplicate_item *find_duplicates(struct item *list); > +void free_duplicates(struct duplicate_item **duplicates); > + > +#endif > 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; > + > + current->next = new_item; > + } > + return new_item; > +} > + > +void sort_list(struct item **list, int sort_by) > +{ > + struct item *current = *list; > + struct item *sorted = NULL; > + struct item *next_item; > + struct item *temp; > + > + if (!(*list) || !((*list)->next)) > + return; > + > + while (current) { > + next_item = current->next; > + if (!sorted || > + (CHECK_ORDER_BY_ADDRESS(sort_by, current, sorted, <) || > + CHECK_ORDER_BY_NAME(sort_by, current, sorted, >=))) { > + current->next = sorted; > + sorted = current; > + } else { > + temp = sorted; > + while (temp->next && > + (CHECK_ORDER_BY_ADDRESS(sort_by, current, temp->next, >=) || > + CHECK_ORDER_BY_NAME(sort_by, current, temp->next, >=))) > + temp = temp->next; > + > + current->next = temp->next; > + temp->next = current; > + } > + current = next_item; > + } > + > + *list = sorted; > +} > + > +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) > +{ > + struct item *right; > + struct item *slow; > + struct item *fast; > + struct item *left; > + > + if (!head || !head->next) > + return head; > + > + slow = head; > + fast = head->next; > + > + while (fast && fast->next) { > + slow = slow->next; > + fast = fast->next->next; > + } > + > + left = head; > + right = slow->next; > + slow->next = NULL; > + > + left = merge_sort(left, sort_by); > + right = merge_sort(right, sort_by); > + > + return merge(left, right, sort_by); > +} > + > +void sort_list_m(struct item **head, int sort_by) > +{ > + if (!(*head) || !((*head)->next)) > + return; > + > + *head = merge_sort(*head, sort_by); > +} > + > +int insert_after(struct item *list, const uint64_t search_addr, > + const char *name, uint64_t addr, char stype) > +{ > + struct item *new_item; > + struct item *current; > + int ret = 0; > + > + current = (list_index[name[0] - 32]) ? list_index[name[0] - 32] : list; > + while (current) { > + if (current->addr == search_addr) { > + new_item = malloc(sizeof(struct item)); > + if (!new_item) > + return ret; > + 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 = current->next; > + current->next = new_item; > + ret = 1; > + break; > + } > + current = current->next; > + } > + return ret; > +} > + > +void free_items(struct item **head) > +{ > + struct item *app, *item_iterator = *head; > + > + while (item_iterator) { > + app = item_iterator; > + item_iterator = item_iterator->next; > + free(app); > + } > + *head = NULL; > +} > 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 > +#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, ...) > +{ > + va_list args; > + > + va_start(args, fmt); > + if (verbose) > + printf(fmt, args); > + > + va_end(args); > +} > + > +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 '.': This is not enough because file path will accept more than that. E.g. '+', '&', '-'. So I think we should check it by '!isalnum()'. (allow-list method) > + *(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}; > + 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) > + 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); > + } > + current = head; > + while (current) { > + printf("%08lx %c %s\n", current->addr, current->stype, current->symb_name); > + current = current->next; > + } > + > + free_items(&head); > + free_duplicates(&duplicate); > + addr2line_cleanup(); > + return 0; > +} > 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" != "${output#.tmp_vmlinux.kallsyms}" ] ; then > + # The kallsyms linking does not need debug symbols included, unless the KALLSYMS_ALIAS. > + if [ ! is_enabled CONFIG_KALLSYMS_ALIAS ] && \ > + [ "$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 Nit: wrong indentation. And ALIAS is not defined if CONFIG_KALLSYMS_ALIAS=n. > + scripts/kallsyms ${kallsymopt} ${1}${ALIAS} > ${2} > } > > # Perform one step in kallsyms generation, including temporary linking of > -- > 2.34.1 > Thank you, -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
