2019-11-23 16:07:09

by Masahiro Yamada

[permalink] [raw]
Subject: [PATCH v2 11/16] scripts/kallsyms: skip ignored symbols very early

Unless the address range matters, symbols can be ignored earlier,
which avoids unneeded memory allocation.

Signed-off-by: Masahiro Yamada <[email protected]>
---

Changes in v2: None

scripts/kallsyms.c | 113 +++++++++++++++++++++++++--------------------
1 file changed, 62 insertions(+), 51 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 056bde436540..843615c1d384 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -18,6 +18,7 @@
*
*/

+#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -79,6 +80,64 @@ static char *sym_name(const struct sym_entry *s)
return (char *)s->sym + 1;
}

+static bool is_ignored_symbol(const char *name, char type)
+{
+ 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[] = {
+ "__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;
+ }
+
+ return false;
+}
+
static int check_symbol_range(const char *sym, unsigned long long addr,
struct addr_range *ranges, int entries)
{
@@ -118,6 +177,9 @@ 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;
@@ -188,38 +250,6 @@ static int symbol_in_range(const 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 const char * const 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 const char * const special_prefixes[] = {
- "__crc_", /* modversions */
- "__efistub_", /* arm64 EFI stub namespace */
- NULL };
-
- static const char * const special_suffixes[] = {
- "_veneer", /* arm */
- "_from_arm", /* arm */
- "_from_thumb", /* arm */
- NULL };
-
- int i;
const char *name = sym_name(s);

/* if --all-symbols is not specified, then symbols outside the text
@@ -241,25 +271,6 @@ static int symbol_valid(const struct sym_entry *s)
return 0;
}

- /* Exclude symbols which vary between passes. */
- for (i = 0; special_symbols[i]; i++)
- if (strcmp(name, special_symbols[i]) == 0)
- return 0;
-
- for (i = 0; special_prefixes[i]; i++) {
- int l = strlen(special_prefixes[i]);
-
- if (strncmp(name, special_prefixes[i], l) == 0)
- return 0;
- }
-
- for (i = 0; special_suffixes[i]; i++) {
- int l = strlen(name) - strlen(special_suffixes[i]);
-
- if (l >= 0 && strcmp(name + l, special_suffixes[i]) == 0)
- return 0;
- }
-
return 1;
}

--
2.17.1