Commit 7d5222a6 authored by Matt Fleming's avatar Matt Fleming Committed by Ingo Molnar

ftrace: align __mcount_loc sections

Impact: add alignment option for recordmcount.pl script

Align the __mcount_loc sections so that architectures with strict
alignment requirements need not worry about performing unaligned
accesses.

This fixes an issue where I was seeing unaligned accesses, which are not
supported on our architecture (the results of an unaligned access are
undefined).
Signed-off-by: default avatarMatt Fleming <matthew.fleming@imgtec.com>
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c76f0694
...@@ -134,6 +134,7 @@ my $section_regex; # Find the start of a section ...@@ -134,6 +134,7 @@ my $section_regex; # Find the start of a section
my $function_regex; # Find the name of a function my $function_regex; # Find the name of a function
# (return offset and func name) # (return offset and func name)
my $mcount_regex; # Find the call site to mcount (return offset) my $mcount_regex; # Find the call site to mcount (return offset)
my $alignment; # The .align value to use for $mcount_section
if ($arch eq "x86") { if ($arch eq "x86") {
if ($bits == 64) { if ($bits == 64) {
...@@ -148,6 +149,7 @@ if ($arch eq "x86_64") { ...@@ -148,6 +149,7 @@ if ($arch eq "x86_64") {
$function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:"; $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$"; $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$";
$type = ".quad"; $type = ".quad";
$alignment = 8;
# force flags for this arch # force flags for this arch
$ld .= " -m elf_x86_64"; $ld .= " -m elf_x86_64";
...@@ -160,6 +162,7 @@ if ($arch eq "x86_64") { ...@@ -160,6 +162,7 @@ if ($arch eq "x86_64") {
$function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:"; $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$"; $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
$type = ".long"; $type = ".long";
$alignment = 4;
# force flags for this arch # force flags for this arch
$ld .= " -m elf_i386"; $ld .= " -m elf_i386";
...@@ -288,6 +291,7 @@ sub update_funcs ...@@ -288,6 +291,7 @@ sub update_funcs
open(FILE, ">$mcount_s") || die "can't create $mcount_s\n"; open(FILE, ">$mcount_s") || die "can't create $mcount_s\n";
$opened = 1; $opened = 1;
print FILE "\t.section $mcount_section,\"a\",\@progbits\n"; print FILE "\t.section $mcount_section,\"a\",\@progbits\n";
print FILE "\t.align $alignment\n";
} }
printf FILE "\t%s %s + %d\n", $type, $ref_func, $offsets[$i] - $offset; printf FILE "\t%s %s + %d\n", $type, $ref_func, $offsets[$i] - $offset;
} }
......
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