diff options
Diffstat (limited to 'scripts/kallsyms.c')
-rw-r--r-- | scripts/kallsyms.c | 287 |
1 files changed, 142 insertions, 145 deletions
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index ae6504d07fd6..fb55f262f42d 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -18,15 +18,14 @@ * */ +#include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <ctype.h> #include <limits.h> -#ifndef ARRAY_SIZE #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0])) -#endif #define KSYM_NAME_LEN 128 @@ -58,9 +57,9 @@ static struct addr_range percpu_range = { static struct sym_entry *table; static unsigned int table_size, table_cnt; -static int all_symbols = 0; -static int absolute_percpu = 0; -static int base_relative = 0; +static int all_symbols; +static int absolute_percpu; +static int base_relative; static int token_profit[0x10000]; @@ -76,18 +75,88 @@ static void usage(void) exit(1); } -/* - * This ignores the intensely annoying "mapping symbols" found - * in ARM ELF files: $a, $t and $d. - */ -static int is_arm_mapping_symbol(const char *str) +static char *sym_name(const struct sym_entry *s) +{ + return (char *)s->sym + 1; +} + +static bool is_ignored_symbol(const char *name, char type) { - return str[0] == '$' && strchr("axtd", str[1]) - && (str[2] == '\0' || str[2] == '.'); + static const char * const ignored_symbols[] = { + /* + * Symbols which vary between passes. Passes 1 and 2 must have + * identical symbol lists. The kallsyms_* symbols below are + * only added after pass 1, they would be included in pass 2 + * when --all-symbols is specified so exclude them to get a + * stable symbol list. + */ + "kallsyms_addresses", + "kallsyms_offsets", + "kallsyms_relative_base", + "kallsyms_num_syms", + "kallsyms_names", + "kallsyms_markers", + "kallsyms_token_table", + "kallsyms_token_index", + /* Exclude linker generated symbols which vary between passes */ + "_SDA_BASE_", /* ppc */ + "_SDA2_BASE_", /* ppc */ + NULL + }; + + static const char * const ignored_prefixes[] = { + "$", /* local symbols for ARM, MIPS, etc. */ + ".LASANPC", /* s390 kasan local symbols */ + "__crc_", /* modversions */ + "__efistub_", /* arm64 EFI stub namespace */ + NULL + }; + + static const char * const ignored_suffixes[] = { + "_from_arm", /* arm */ + "_from_thumb", /* arm */ + "_veneer", /* arm */ + NULL + }; + + const char * const *p; + + /* Exclude symbols which vary between passes. */ + for (p = ignored_symbols; *p; p++) + if (!strcmp(name, *p)) + return true; + + for (p = ignored_prefixes; *p; p++) + if (!strncmp(name, *p, strlen(*p))) + return true; + + for (p = ignored_suffixes; *p; p++) { + int l = strlen(name) - strlen(*p); + + if (l >= 0 && !strcmp(name + l, *p)) + return true; + } + + if (type == 'U' || type == 'u') + return true; + /* exclude debugging symbols */ + if (type == 'N' || type == 'n') + return true; + + if (toupper(type) == 'A') { + /* Keep these useful absolute symbols */ + if (strcmp(name, "__kernel_syscall_via_break") && + strcmp(name, "__kernel_syscall_via_epc") && + strcmp(name, "__kernel_sigtramp") && + strcmp(name, "__gp")) + return true; + } + + return false; } -static int check_symbol_range(const char *sym, unsigned long long addr, - struct addr_range *ranges, int entries) +static void check_symbol_range(const char *sym, unsigned long long addr, + struct addr_range *ranges, int entries) { size_t i; struct addr_range *ar; @@ -97,14 +166,12 @@ static int check_symbol_range(const char *sym, unsigned long long addr, if (strcmp(sym, ar->start_sym) == 0) { ar->start = addr; - return 0; + return; } else if (strcmp(sym, ar->end_sym) == 0) { ar->end = addr; - return 0; + return; } } - - return 1; } static int read_symbol(FILE *in, struct sym_entry *s) @@ -125,34 +192,15 @@ static int read_symbol(FILE *in, struct sym_entry *s) return -1; } + if (is_ignored_symbol(sym, stype)) + return -1; + /* Ignore most absolute/undefined (?) symbols. */ if (strcmp(sym, "_text") == 0) _text = s->addr; - else if (check_symbol_range(sym, s->addr, text_ranges, - ARRAY_SIZE(text_ranges)) == 0) - /* nothing to do */; - else if (toupper(stype) == 'A') - { - /* Keep these useful absolute symbols */ - if (strcmp(sym, "__kernel_syscall_via_break") && - strcmp(sym, "__kernel_syscall_via_epc") && - strcmp(sym, "__kernel_sigtramp") && - strcmp(sym, "__gp")) - return -1; - } - else if (toupper(stype) == 'U' || - is_arm_mapping_symbol(sym)) - return -1; - /* exclude also MIPS ELF local symbols ($L123 instead of .L123) */ - else if (sym[0] == '$') - return -1; - /* exclude debugging symbols */ - else if (stype == 'N' || stype == 'n') - return -1; - /* exclude s390 kasan local symbols */ - else if (!strncmp(sym, ".LASANPC", 8)) - return -1; + check_symbol_range(sym, s->addr, text_ranges, ARRAY_SIZE(text_ranges)); + check_symbol_range(sym, s->addr, &percpu_range, 1); /* include the type field in the symbol name, so that it gets * compressed together */ @@ -163,22 +211,19 @@ static int read_symbol(FILE *in, struct sym_entry *s) "unable to allocate required amount of memory\n"); exit(EXIT_FAILURE); } - strcpy((char *)s->sym + 1, sym); + strcpy(sym_name(s), sym); s->sym[0] = stype; s->percpu_absolute = 0; - /* Record if we've found __per_cpu_start/end. */ - check_symbol_range(sym, s->addr, &percpu_range, 1); - return 0; } -static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges, - int entries) +static int symbol_in_range(const struct sym_entry *s, + const struct addr_range *ranges, int entries) { size_t i; - struct addr_range *ar; + const struct addr_range *ar; for (i = 0; i < entries; ++i) { ar = &ranges[i]; @@ -190,41 +235,9 @@ static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges, return 0; } -static int symbol_valid(struct sym_entry *s) +static int symbol_valid(const struct sym_entry *s) { - /* Symbols which vary between passes. Passes 1 and 2 must have - * identical symbol lists. The kallsyms_* symbols below are only added - * after pass 1, they would be included in pass 2 when --all-symbols is - * specified so exclude them to get a stable symbol list. - */ - static char *special_symbols[] = { - "kallsyms_addresses", - "kallsyms_offsets", - "kallsyms_relative_base", - "kallsyms_num_syms", - "kallsyms_names", - "kallsyms_markers", - "kallsyms_token_table", - "kallsyms_token_index", - - /* Exclude linker generated symbols which vary between passes */ - "_SDA_BASE_", /* ppc */ - "_SDA2_BASE_", /* ppc */ - NULL }; - - static char *special_prefixes[] = { - "__crc_", /* modversions */ - "__efistub_", /* arm64 EFI stub namespace */ - NULL }; - - static char *special_suffixes[] = { - "_veneer", /* arm */ - "_from_arm", /* arm */ - "_from_thumb", /* arm */ - NULL }; - - int i; - char *sym_name = (char *)s->sym + 1; + const char *name = sym_name(s); /* if --all-symbols is not specified, then symbols outside the text * and inittext sections are discarded */ @@ -239,35 +252,37 @@ static int symbol_valid(struct sym_entry *s) * rules. */ if ((s->addr == text_range_text->end && - strcmp(sym_name, - text_range_text->end_sym)) || + strcmp(name, text_range_text->end_sym)) || (s->addr == text_range_inittext->end && - strcmp(sym_name, - text_range_inittext->end_sym))) + strcmp(name, text_range_inittext->end_sym))) return 0; } - /* Exclude symbols which vary between passes. */ - for (i = 0; special_symbols[i]; i++) - if (strcmp(sym_name, special_symbols[i]) == 0) - return 0; + return 1; +} - for (i = 0; special_prefixes[i]; i++) { - int l = strlen(special_prefixes[i]); +/* remove all the invalid symbols from the table */ +static void shrink_table(void) +{ + unsigned int i, pos; - if (l <= strlen(sym_name) && - strncmp(sym_name, special_prefixes[i], l) == 0) - return 0; + pos = 0; + for (i = 0; i < table_cnt; i++) { + if (symbol_valid(&table[i])) { + if (pos != i) + table[pos] = table[i]; + pos++; + } else { + free(table[i].sym); + } } + table_cnt = pos; - for (i = 0; special_suffixes[i]; i++) { - int l = strlen(sym_name) - strlen(special_suffixes[i]); - - if (l >= 0 && strcmp(sym_name + l, special_suffixes[i]) == 0) - return 0; + /* When valid symbol is not registered, exit to error */ + if (!table_cnt) { + fprintf(stderr, "No valid symbol.\n"); + exit(1); } - - return 1; } static void read_map(FILE *in) @@ -288,7 +303,7 @@ static void read_map(FILE *in) } } -static void output_label(char *label) +static void output_label(const char *label) { printf(".globl %s\n", label); printf("\tALGN\n"); @@ -297,7 +312,7 @@ static void output_label(char *label) /* uncompress a compressed symbol. When this function is called, the best table * might still be compressed itself, so the function needs to be recursive */ -static int expand_symbol(unsigned char *data, int len, char *result) +static int expand_symbol(const unsigned char *data, int len, char *result) { int c, rlen, total=0; @@ -322,7 +337,7 @@ static int expand_symbol(unsigned char *data, int len, char *result) return total; } -static int symbol_absolute(struct sym_entry *s) +static int symbol_absolute(const struct sym_entry *s) { return s->percpu_absolute; } @@ -460,7 +475,7 @@ static void write_src(void) /* table lookup compression functions */ /* count all the possible tokens in a symbol */ -static void learn_symbol(unsigned char *symbol, int len) +static void learn_symbol(const unsigned char *symbol, int len) { int i; @@ -469,7 +484,7 @@ static void learn_symbol(unsigned char *symbol, int len) } /* decrease the count for all the possible tokens in a symbol */ -static void forget_symbol(unsigned char *symbol, int len) +static void forget_symbol(const unsigned char *symbol, int len) { int i; @@ -477,24 +492,17 @@ static void forget_symbol(unsigned char *symbol, int len) token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--; } -/* remove all the invalid symbols from the table and do the initial token count */ +/* do the initial token count */ static void build_initial_tok_table(void) { - unsigned int i, pos; + unsigned int i; - pos = 0; - for (i = 0; i < table_cnt; i++) { - if ( symbol_valid(&table[i]) ) { - if (pos != i) - table[pos] = table[i]; - learn_symbol(table[pos].sym, table[pos].len); - pos++; - } - } - table_cnt = pos; + for (i = 0; i < table_cnt; i++) + learn_symbol(table[i].sym, table[i].len); } -static void *find_token(unsigned char *str, int len, unsigned char *token) +static unsigned char *find_token(unsigned char *str, int len, + const unsigned char *token) { int i; @@ -507,7 +515,7 @@ static void *find_token(unsigned char *str, int len, unsigned char *token) /* replace a given token in all the valid symbols. Use the sampled symbols * to update the counts */ -static void compress_symbols(unsigned char *str, int idx) +static void compress_symbols(const unsigned char *str, int idx) { unsigned int i, len, size; unsigned char *p1, *p2; @@ -614,19 +622,13 @@ static void optimize_token_table(void) insert_real_symbols_in_table(); - /* When valid symbol is not registered, exit to error */ - if (!table_cnt) { - fprintf(stderr, "No valid symbol.\n"); - exit(1); - } - optimize_result(); } /* guess for "linker script provide" symbol */ static int may_be_linker_script_provide_symbol(const struct sym_entry *se) { - const char *symbol = (char *)se->sym + 1; + const char *symbol = sym_name(se); int len = se->len - 1; if (len < 8) @@ -658,16 +660,6 @@ static int may_be_linker_script_provide_symbol(const struct sym_entry *se) return 0; } -static int prefix_underscores_count(const char *str) -{ - const char *tail = str; - - while (*tail == '_') - tail++; - - return tail - str; -} - static int compare_symbols(const void *a, const void *b) { const struct sym_entry *sa; @@ -696,8 +688,8 @@ static int compare_symbols(const void *a, const void *b) return wa - wb; /* sort by the number of prefix underscores */ - wa = prefix_underscores_count((const char *)sa->sym + 1); - wb = prefix_underscores_count((const char *)sb->sym + 1); + wa = strspn(sym_name(sa), "_"); + wb = strspn(sym_name(sb), "_"); if (wa != wb) return wa - wb; @@ -731,11 +723,15 @@ static void record_relative_base(void) { unsigned int i; - relative_base = -1ULL; for (i = 0; i < table_cnt; i++) - if (!symbol_absolute(&table[i]) && - table[i].addr < relative_base) + if (!symbol_absolute(&table[i])) { + /* + * The table is sorted by address. + * Take the first non-absolute symbol value. + */ relative_base = table[i].addr; + return; + } } int main(int argc, char **argv) @@ -756,11 +752,12 @@ int main(int argc, char **argv) usage(); read_map(stdin); + shrink_table(); if (absolute_percpu) make_percpus_absolute(); + sort_symbols(); if (base_relative) record_relative_base(); - sort_symbols(); optimize_token_table(); write_src(); |