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.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- arch/arm64/Kconfig | 2 ++ scripts/recordmcount.c | 9 +++++++++ scripts/recordmcount.pl | 5 +++++ 3 files changed, 16 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 27bbcfc..340e344 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -27,12 +27,14 @@ config ARM64 select HARDIRQS_SW_RESEND select HAVE_ARCH_JUMP_LABEL select HAVE_ARCH_TRACEHOOK + select HAVE_C_RECORDMCOUNT select HAVE_DEBUG_BUGVERBOSE select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_API_DEBUG select HAVE_DMA_ATTRS select HAVE_DMA_CONTIGUOUS select HAVE_EFFICIENT_UNALIGNED_ACCESS + select HAVE_FTRACE_MCOUNT_RECORD select HAVE_GENERIC_DMA_COHERENT select HAVE_HW_BREAKPOINT if PERF_EVENTS select HAVE_MEMBLOCK 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"; + break; case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break; case EM_METAG: reltype = R_METAG_ADDR32; altmcount = "_mcount_wrapper"; 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'; + $mcount_regex = "^\s*([0-9a-fA-F]+):\s*R_AARCH64_CALL26\s+_mcount$"; + $type = ".quad"; } elsif ($arch eq "ia64") { $mcount_regex = "^\s*([0-9a-fA-F]+):.*\s_mcount$"; $type = "data8";