diff options
| author | Zhen Lei <thunder.leizhen@huawei.com> | 2022-11-02 16:49:16 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-25 12:03:16 +0200 |
| commit | da359f699f5942ca383f528d144fc17c7c95e78a (patch) | |
| tree | f0e5e71445eaa21e193c4343163d11ccec5ed603 | |
| parent | 3918cada8f1b247ad11a41872584232361e1d140 (diff) | |
kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[]
[ Upstream commit 19bd8981dc2ee35fdc81ab1b0104b607c917d470 ]
kallsyms_seqs_of_names[] records the symbol index sorted by address, the
maximum value in kallsyms_seqs_of_names[] is the number of symbols. And
2^24 = 16777216, which means that three bytes are enough to store the
index. This can help us save (1 * kallsyms_num_syms) bytes of memory.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Stable-dep-of: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/kallsyms.c | 18 | ||||
| -rw-r--r-- | kernel/kallsyms_internal.h | 2 | ||||
| -rw-r--r-- | scripts/kallsyms.c | 5 |
3 files changed, 19 insertions, 6 deletions
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index ad3cccb0970f..32cba13eee6c 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -197,6 +197,16 @@ static int compare_symbol_name(const char *name, char *namebuf) return strcmp(name, namebuf); } +static unsigned int get_symbol_seq(int index) +{ + unsigned int i, seq = 0; + + for (i = 0; i < 3; i++) + seq = (seq << 8) | kallsyms_seqs_of_names[3 * index + i]; + + return seq; +} + static int kallsyms_lookup_names(const char *name, unsigned int *start, unsigned int *end) @@ -211,7 +221,7 @@ static int kallsyms_lookup_names(const char *name, while (low <= high) { mid = low + (high - low) / 2; - seq = kallsyms_seqs_of_names[mid]; + seq = get_symbol_seq(mid); off = get_symbol_offset(seq); kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); ret = compare_symbol_name(name, namebuf); @@ -228,7 +238,7 @@ static int kallsyms_lookup_names(const char *name, low = mid; while (low) { - seq = kallsyms_seqs_of_names[low - 1]; + seq = get_symbol_seq(low - 1); off = get_symbol_offset(seq); kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); if (compare_symbol_name(name, namebuf)) @@ -240,7 +250,7 @@ static int kallsyms_lookup_names(const char *name, if (end) { high = mid; while (high < kallsyms_num_syms - 1) { - seq = kallsyms_seqs_of_names[high + 1]; + seq = get_symbol_seq(high + 1); off = get_symbol_offset(seq); kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); if (compare_symbol_name(name, namebuf)) @@ -265,7 +275,7 @@ unsigned long kallsyms_lookup_name(const char *name) ret = kallsyms_lookup_names(name, &i, NULL); if (!ret) - return kallsyms_sym_address(kallsyms_seqs_of_names[i]); + return kallsyms_sym_address(get_symbol_seq(i)); return module_kallsyms_lookup_name(name); } diff --git a/kernel/kallsyms_internal.h b/kernel/kallsyms_internal.h index a04b7a5cb1e3..27fabdcc40f5 100644 --- a/kernel/kallsyms_internal.h +++ b/kernel/kallsyms_internal.h @@ -26,6 +26,6 @@ extern const char kallsyms_token_table[] __weak; extern const u16 kallsyms_token_index[] __weak; extern const unsigned int kallsyms_markers[] __weak; -extern const unsigned int kallsyms_seqs_of_names[] __weak; +extern const u8 kallsyms_seqs_of_names[] __weak; #endif // LINUX_KALLSYMS_INTERNAL_H_ diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 80aab2aa7224..ff8cce175784 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -602,7 +602,10 @@ static void write_src(void) sort_symbols_by_name(); output_label("kallsyms_seqs_of_names"); for (i = 0; i < table_cnt; i++) - printf("\t.long\t%u\n", table[i]->seq); + printf("\t.byte 0x%02x, 0x%02x, 0x%02x\n", + (unsigned char)(table[i]->seq >> 16), + (unsigned char)(table[i]->seq >> 8), + (unsigned char)(table[i]->seq >> 0)); printf("\n"); output_label("kallsyms_token_table"); |