MIPS: Tracing: Add dynamic function tracer support

[safe/jmp/linux-2.6] / scripts / recordmcount.pl

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index ab368e8..92f09fe 100755 (executable)
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -295,6 +295,58 @@ if ($arch eq "x86_64") {
     $ld .= " -m elf64_sparc";
     $cc .= " -m64";
     $objcopy .= " -O elf64-sparc";
+} elsif ($arch eq "mips") {
+    # To enable module support, we need to enable the -mlong-calls option
+    # of gcc for module, after using this option, we can not get the real
+    # offset of the calling to _mcount, but the offset of the lui
+    # instruction or the addiu one. herein, we record the address of the
+    # first one, and then we can replace this instruction by a branch
+    # instruction to jump over the profiling function to filter the
+    # indicated functions, or swith back to the lui instruction to trace
+    # them, which means dynamic tracing.
+    #
+    #       c: 3c030000        lui     v1,0x0
+    #                  c: R_MIPS_HI16  _mcount
+    #                  c: R_MIPS_NONE  *ABS*
+    #                  c: R_MIPS_NONE  *ABS*
+    #      10: 64630000        daddiu  v1,v1,0
+    #                  10: R_MIPS_LO16 _mcount
+    #                  10: R_MIPS_NONE *ABS*
+    #                  10: R_MIPS_NONE *ABS*
+    #      14: 03e0082d        move    at,ra
+    #      18: 0060f809        jalr    v1
+    #
+    # for the kernel:
+    #
+    #     10:   03e0082d        move    at,ra
+    #    14:   0c000000        jal     0 <loongson_halt>
+    #                    14: R_MIPS_26   _mcount
+    #                    14: R_MIPS_NONE *ABS*
+    #                    14: R_MIPS_NONE *ABS*
+    #   18:   00020021        nop
+    if ($is_module eq "0") {
+           $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
+    } else {
+           $mcount_regex = "^\\s*([0-9a-fA-F]+): R_MIPS_HI16\\s+_mcount\$";
+    }
+    $objdump .= " -Melf-trad".$endian."mips ";
+
+    if ($endian eq "big") {
+           $endian = " -EB ";
+           $ld .= " -melf".$bits."btsmip";
+    } else {
+           $endian = " -EL ";
+           $ld .= " -melf".$bits."ltsmip";
+    }
+
+    $cc .= " -mno-abicalls -fno-pic -mabi=" . $bits . $endian;
+    $ld .= $endian;
+
+    if ($bits == 64) {
+           $function_regex =
+               "^([0-9a-fA-F]+)\\s+<(.|[^\$]L.*?|\$[^L].*?|[^\$][^L].*?)>:";
+           $type = ".dword";
+    }
 } elsif ($arch eq "microblaze") {
     # Microblaze calls '_mcount' instead of plain 'mcount'.
     $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";