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authorMing Lei <tom.leiming@gmail.com>2013-11-02 09:11:33 +1030
committerRusty Russell <rusty@rustcorp.com.au>2013-11-02 09:13:02 +1030
commitf6537f2f0eba4eba3354e48dbe3047db6d8b6254 (patch)
tree20541922629260f7e48eaacc9c5e590d33a461c4
parent12aee278b50c4a94a93fa0b4d201ae35d792c696 (diff)
downloadlwn-f6537f2f0eba4eba3354e48dbe3047db6d8b6254.tar.gz
lwn-f6537f2f0eba4eba3354e48dbe3047db6d8b6254.zip
scripts/kallsyms: filter symbols not in kernel address space
This patch uses CONFIG_PAGE_OFFSET to filter symbols which are not in kernel address space because these symbols are generally for generating code purpose and can't be run at kernel mode, so we needn't keep them in /proc/kallsyms. For example, on ARM there are some symbols which may be linked in relocatable code section, then perf can't parse symbols any more from /proc/kallsyms, this patch fixes the problem (introduced b9b32bf70f2fb710b07c94e13afbc729afe221da) Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@vger.kernel.org
-rw-r--r--scripts/kallsyms.c12
-rw-r--r--scripts/link-vmlinux.sh2
2 files changed, 13 insertions, 1 deletions
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 487ac6f37ca2..9a11f9f799f4 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -55,6 +55,7 @@ static struct sym_entry *table;
static unsigned int table_size, table_cnt;
static int all_symbols = 0;
static char symbol_prefix_char = '\0';
+static unsigned long long kernel_start_addr = 0;
int token_profit[0x10000];
@@ -65,7 +66,10 @@ unsigned char best_table_len[256];
static void usage(void)
{
- fprintf(stderr, "Usage: kallsyms [--all-symbols] [--symbol-prefix=<prefix char>] < in.map > out.S\n");
+ fprintf(stderr, "Usage: kallsyms [--all-symbols] "
+ "[--symbol-prefix=<prefix char>] "
+ "[--page-offset=<CONFIG_PAGE_OFFSET>] "
+ "< in.map > out.S\n");
exit(1);
}
@@ -194,6 +198,9 @@ static int symbol_valid(struct sym_entry *s)
int i;
int offset = 1;
+ if (s->addr < kernel_start_addr)
+ return 0;
+
/* skip prefix char */
if (symbol_prefix_char && *(s->sym + 1) == symbol_prefix_char)
offset++;
@@ -646,6 +653,9 @@ int main(int argc, char **argv)
if ((*p == '"' && *(p+2) == '"') || (*p == '\'' && *(p+2) == '\''))
p++;
symbol_prefix_char = *p;
+ } else if (strncmp(argv[i], "--page-offset=", 14) == 0) {
+ const char *p = &argv[i][14];
+ kernel_start_addr = strtoull(p, NULL, 16);
} else
usage();
}
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 014994936b1c..32b10f53d0b4 100644
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -82,6 +82,8 @@ kallsyms()
kallsymopt="${kallsymopt} --all-symbols"
fi
+ kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET"
+
local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"