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authorSteven Rostedt <rostedt@goodmis.org>2008-10-23 09:32:58 -0400
committerIngo Molnar <mingo@elte.hu>2008-10-23 15:58:20 +0200
commit34698bcbdf7b0629d6c873b5da7c63073fb45361 (patch)
tree25086d1711e4a99cc3c36c9b96567d2052d06b0d
parentdce9d18adde74b8e36b9e4a8a49ddf066bad0b3b (diff)
downloadlinux-34698bcbdf7b0629d6c873b5da7c63073fb45361.tar.bz2
ftrace: dynamic ftrace process only text section
The text section stays in memory without ever leaving. With the exception of modules, but modules know how to handle that case. With the dynamic ftrace tracer, we need to make sure that it does not try to modify code that no longer exists. The only safe section is .text. This patch changes the recordmcount script to only record the mcount calls in the .text sections. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rwxr-xr-xscripts/recordmcount.pl17
1 files changed, 14 insertions, 3 deletions
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index c1c618cd96f6..6b9fe3eb8360 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -109,6 +109,11 @@ if ($#ARGV < 6) {
my ($arch, $bits, $objdump, $objcopy, $cc,
$ld, $nm, $rm, $mv, $inputfile) = @ARGV;
+# Acceptable sections to record.
+my %text_sections = (
+ ".text" => 1,
+);
+
$objdump = "objdump" if ((length $objdump) == 0);
$objcopy = "objcopy" if ((length $objcopy) == 0);
$cc = "gcc" if ((length $cc) == 0);
@@ -139,7 +144,7 @@ if ($arch eq "x86") {
}
if ($arch eq "x86_64") {
- $section_regex = "Disassembly of section";
+ $section_regex = "Disassembly of section\\s+(\\S+):";
$function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$";
$type = ".quad";
@@ -151,7 +156,7 @@ if ($arch eq "x86_64") {
$cc .= " -m64";
} elsif ($arch eq "i386") {
- $section_regex = "Disassembly of section";
+ $section_regex = "Disassembly of section\\s+(\\S+):";
$function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
$type = ".long";
@@ -298,7 +303,13 @@ my $text;
while (<IN>) {
# is it a section?
if (/$section_regex/) {
- $read_function = 1;
+
+ # Only record text sections that we know are safe
+ if (defined($text_sections{$1})) {
+ $read_function = 1;
+ } else {
+ $read_function = 0;
+ }
# print out any recorded offsets
update_funcs() if ($text_found);