Eric Lee / linux-smarc-t335x-v3.2

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Commit 7d5222a6afa4e429f55df8c086adb747837cbdf5

Authored by Matt Fleming
Committed by Ingo Molnar
1 parent c76f06945b
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

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: Matt Fleming <matthew.fleming@imgtec.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Showing 1 changed file with 4 additions and 0 deletions Side-by-side Diff

scripts/recordmcount.pl
Diff comments   View file @ 7d5222a
... ... @@ -134,6 +134,7 @@
134 134 my $function_regex; # Find the name of a function
135 135 # (return offset and func name)
136 136 my $mcount_regex; # Find the call site to mcount (return offset)
  137 +my $alignment; # The .align value to use for $mcount_section
137 138  
138 139 if ($arch eq "x86") {
139 140 if ($bits == 64) {
... ... @@ -148,6 +149,7 @@
148 149 $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
149 150 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$";
150 151 $type = ".quad";
  152 + $alignment = 8;
151 153  
152 154 # force flags for this arch
153 155 $ld .= " -m elf_x86_64";
... ... @@ -160,6 +162,7 @@
160 162 $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
161 163 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
162 164 $type = ".long";
  165 + $alignment = 4;
163 166  
164 167 # force flags for this arch
165 168 $ld .= " -m elf_i386";
... ... @@ -288,6 +291,7 @@
288 291 open(FILE, ">$mcount_s") || die "can't create $mcount_s\n";
289 292 $opened = 1;
290 293 print FILE "\t.section $mcount_section,\"a\",\@progbits\n";
  294 + print FILE "\t.align $alignment\n";
291 295 }
292 296 printf FILE "\t%s %s + %d\n", $type, $ref_func, $offsets[$i] - $offset;
293 297 }