| From: Felix Fietkau <nbd@nbd.name> |
| Subject: kernel: add a config option for keeping the kallsyms table uncompressed, saving ~9kb kernel size after lzma on ar71xx |
| |
| [john@phrozen.org: added to my upstream queue 30.12.2016] |
| lede-commit: e0e3509b5ce2ccf93d4d67ea907613f5f7ec2eed |
| Signed-off-by: Felix Fietkau <nbd@nbd.name> |
| --- |
| init/Kconfig | 11 +++++++++++ |
| kernel/kallsyms.c | 8 ++++++++ |
| scripts/kallsyms.c | 12 ++++++++++++ |
| scripts/link-vmlinux.sh | 4 ++++ |
| 4 files changed, 35 insertions(+) |
| |
| --- a/init/Kconfig |
| +++ b/init/Kconfig |
| @@ -1289,6 +1289,17 @@ config SYSCTL_ARCH_UNALIGN_ALLOW |
| the unaligned access emulation. |
| see arch/parisc/kernel/unaligned.c for reference |
| |
| +config KALLSYMS_UNCOMPRESSED |
| + bool "Keep kallsyms uncompressed" |
| + depends on KALLSYMS |
| + help |
| + Normally kallsyms contains compressed symbols (using a token table), |
| + reducing the uncompressed kernel image size. Keeping the symbol table |
| + uncompressed significantly improves the size of this part in compressed |
| + kernel images. |
| + |
| + Say N unless you need compressed kernel images to be small. |
| + |
| config HAVE_PCSPKR_PLATFORM |
| bool |
| |
| --- a/kernel/kallsyms.c |
| +++ b/kernel/kallsyms.c |
| @@ -75,6 +75,11 @@ static unsigned int kallsyms_expand_symb |
| * For every byte on the compressed symbol data, copy the table |
| * entry for that byte. |
| */ |
| +#ifdef CONFIG_KALLSYMS_UNCOMPRESSED |
| + memcpy(result, data + 1, len - 1); |
| + result += len - 1; |
| + len = 0; |
| +#endif |
| while (len) { |
| tptr = &kallsyms_token_table[kallsyms_token_index[*data]]; |
| data++; |
| @@ -107,6 +112,9 @@ tail: |
| */ |
| static char kallsyms_get_symbol_type(unsigned int off) |
| { |
| +#ifdef CONFIG_KALLSYMS_UNCOMPRESSED |
| + return kallsyms_names[off + 1]; |
| +#endif |
| /* |
| * Get just the first code, look it up in the token table, |
| * and return the first char from this token. |
| --- a/scripts/kallsyms.c |
| +++ b/scripts/kallsyms.c |
| @@ -59,6 +59,7 @@ 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 uncompressed = 0; |
| static int absolute_percpu = 0; |
| static int base_relative = 0; |
| |
| @@ -440,6 +441,9 @@ static void write_src(void) |
| |
| free(markers); |
| |
| + if (uncompressed) |
| + return; |
| + |
| output_label("kallsyms_token_table"); |
| off = 0; |
| for (i = 0; i < 256; i++) { |
| @@ -500,6 +504,9 @@ static void *find_token(unsigned char *s |
| { |
| int i; |
| |
| + if (uncompressed) |
| + return NULL; |
| + |
| for (i = 0; i < len - 1; i++) { |
| if (str[i] == token[0] && str[i+1] == token[1]) |
| return &str[i]; |
| @@ -572,6 +579,9 @@ static void optimize_result(void) |
| { |
| int i, best; |
| |
| + if (uncompressed) |
| + return; |
| + |
| /* using the '\0' symbol last allows compress_symbols to use standard |
| * fast string functions */ |
| for (i = 255; i >= 0; i--) { |
| @@ -751,6 +761,8 @@ int main(int argc, char **argv) |
| absolute_percpu = 1; |
| else if (strcmp(argv[i], "--base-relative") == 0) |
| base_relative = 1; |
| + else if (strcmp(argv[i], "--uncompressed") == 0) |
| + uncompressed = 1; |
| else |
| usage(); |
| } |
| --- a/scripts/link-vmlinux.sh |
| +++ b/scripts/link-vmlinux.sh |
| @@ -160,6 +160,10 @@ kallsyms() |
| kallsymopt="${kallsymopt} --base-relative" |
| fi |
| |
| + if [ -n "${CONFIG_KALLSYMS_UNCOMPRESSED}" ]; then |
| + kallsymopt="${kallsymopt} --uncompressed" |
| + fi |
| + |
| local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ |
| ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}" |
| |