Commit f6537f2f authored by Ming Lei's avatar Ming Lei Committed by Rusty Russell
Browse files

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 b9b32bf7)

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: stable@vger.kernel.org
parent 12aee278

scripts/kallsyms.c

+11 −1
Original line number Diff line number Diff line
@@ -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();

		}

scripts/link-vmlinux.sh

+2 −0
Original line number Diff line number Diff line
@@ -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}"

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