Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756921Ab3J1Pt0 (ORCPT <rfc822;w@1wt.eu>);
	Mon, 28 Oct 2013 11:49:26 -0400
Received: from mail-pa0-f49.google.com ([209.85.220.49]:33330 "EHLO
	mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1756004Ab3J1PtZ (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 28 Oct 2013 11:49:25 -0400
From: Ming Lei <tom.leiming@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Cc: Rusty Russell <rusty@rustcorp.com.au>, Ming Lei <tom.leiming@gmail.com>,
        Russell King <linux@arm.linux.org.uk>,
        linux-arm-kernel@lists.infradead.org, Michal Marek <mmarek@suse.cz>
Subject: [PATCH] scripts/kallsyms: filter symbols not in kernel address space
Date: Mon, 28 Oct 2013 23:48:59 +0800
Message-Id: <1382975339-25831-1-git-send-email-tom.leiming@gmail.com>
X-Mailer: git-send-email 1.7.9.5
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 2792
Lines: 85

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 are
linked in relocatable code section, then perf can't parse
symbols any more from /proc/kallsyms, and this patch fixes
the problem.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Michal Marek <mmarek@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 scripts/kallsyms.c      |   12 +++++++++++-
 scripts/link-vmlinux.sh |    2 ++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 487ac6f..9a11f9f 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 0149949..32b10f5 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}"
 
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/