6.1-stable review patch. If anyone has any objections, please let me know.
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From: Zhen Lei thunder.leizhen@huawei.com
[ 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 --- kernel/kallsyms.c | 18 ++++++++++++++---- kernel/kallsyms_internal.h | 2 +- scripts/kallsyms.c | 5 ++++- 3 files changed, 19 insertions(+), 6 deletions(-)
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index ad3cccb0970f8..32cba13eee6c4 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 a04b7a5cb1e3e..27fabdcc40f57 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 80aab2aa72246..ff8cce1757849 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");