On Thu, Mar 13, 2014 at 10:13:46AM +0000, AKASHI Takahiro wrote:
Recordmcount utility under scripts is run, after compiling each object, to find out all the locations of calling _mcount() and put them into specific seciton named __mcount_loc. Then linker collects all such information into a table in the kernel image (between __start_mcount_loc and __stop_mcount_loc) for later use by ftrace.
This patch adds arm64 specific definitions to identify such locations. There are two types of implementation, C and Perl. On arm64, only C version is used to build the kernel now that CONFIG_HAVE_C_RECORDMCOUNT is on. But Perl version is also maintained.
This patch also contains a workaround just in case where a header file, elf.h, on host machine doesn't have definitions of EM_AARCH64 nor R_AARCH64_ABS64. Without them, compiling C version of recordmcount will fail.
[...]
diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index 9c22317..047c8cd 100644 --- a/scripts/recordmcount.c +++ b/scripts/recordmcount.c @@ -40,6 +40,11 @@ #define R_METAG_NONE 3 #endif +#ifndef EM_AARCH64 +#define EM_AARCH64 183 +#define R_AARCH64_ABS64 257 +#endif
static int fd_map; /* File descriptor for file being modified. */ static int mmap_failed; /* Boolean flag. */ static void *ehdr_curr; /* current ElfXX_Ehdr * for resource cleanup */ @@ -347,6 +352,10 @@ do_file(char const *const fname) case EM_ARM: reltype = R_ARM_ABS32; altmcount = "__gnu_mcount_nc"; break;
- case EM_AARCH64:
reltype = R_AARCH64_ABS64;altmcount = "_mcount";
Shouldn't you be setting gpfx = '_' instead of overriding altmcount like this?
break;diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl index 91280b8..397b6b8 100755 --- a/scripts/recordmcount.pl +++ b/scripts/recordmcount.pl @@ -279,6 +279,11 @@ if ($arch eq "x86_64") { $mcount_regex = "^\s*([0-9a-fA-F]+):\s*R_ARM_(CALL|PC24|THM_CALL)" . "\s+(__gnu_mcount_nc|mcount)$"; +} elsif ($arch eq "arm64") {
- $alignment = 3;
- $section_type = '%progbits';
- $mcount_regex = "^\s*([0-9a-fA-F]+):\s*R_AARCH64_CALL26\s+_mcount$";
What about "mcount" (i.e. no underscore)?
Will