Le 29/08/2022 à 07:52, Sathvika Vasireddy a écrit :
> This patch enables objtool --mcount on powerpc, and
> adds implementation specific to powerpc.
>
> Signed-off-by: Sathvika Vasireddy <s...@linux.ibm.com>
> ---
> arch/powerpc/Kconfig | 1 +
> tools/objtool/arch/powerpc/decode.c | 22 +++++++++++++++++++
> tools/objtool/arch/powerpc/include/arch/elf.h | 2 ++
> 3 files changed, 25 insertions(+)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index dc05cd23c233..6be2e68fa9eb 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -238,6 +238,7 @@ config PPC
> select HAVE_NMI if PERF_EVENTS || (PPC64 &&
> PPC_BOOK3S)
> select HAVE_OPTPROBES
> select HAVE_OBJTOOL if PPC32 || MPROFILE_KERNEL
> + select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
> select HAVE_PERF_EVENTS
> select HAVE_PERF_EVENTS_NMI if PPC64
> select HAVE_PERF_REGS
> diff --git a/tools/objtool/arch/powerpc/decode.c
> b/tools/objtool/arch/powerpc/decode.c
> index 8b6a14680da7..b71c265ed503 100644
> --- a/tools/objtool/arch/powerpc/decode.c
> +++ b/tools/objtool/arch/powerpc/decode.c
> @@ -9,6 +9,14 @@
> #include <objtool/builtin.h>
> #include <objtool/endianness.h>
>
> +bool arch_ftrace_match(char *name)
> +{
> + if (!strcmp(name, "_mcount"))
> + return true;
> +
> + return false;
Same as for x86, could be:
return !strcmp(name, "_mcount");
Reviewed-by: Christophe Leroy <christophe.le...@csgroup.eu>
> +}
> +
> unsigned long arch_dest_reloc_offset(int addend)
> {
> return addend;
> @@ -41,12 +49,26 @@ int arch_decode_instruction(struct objtool_file *file,
> const struct section *sec
> struct list_head *ops_list)
> {
> u32 insn;
> + unsigned int opcode;
>
> *immediate = 0;
> insn = bswap_if_needed(file->elf, *(u32 *)(sec->data->d_buf + offset));
> *len = 4;
> *type = INSN_OTHER;
>
> + opcode = insn >> 26;
> +
> + switch (opcode) {
> + case 18: /* bl */
> + if ((insn & 3) == 1) {
> + *type = INSN_CALL;
> + *immediate = insn & 0x3fffffc;
> + if (*immediate & 0x2000000)
> + *immediate -= 0x4000000;
> + }
> + break;
> + }
> +
> return 0;
> }
>
> diff --git a/tools/objtool/arch/powerpc/include/arch/elf.h
> b/tools/objtool/arch/powerpc/include/arch/elf.h
> index 3c8ebb7d2a6b..73f9ae172fe5 100644
> --- a/tools/objtool/arch/powerpc/include/arch/elf.h
> +++ b/tools/objtool/arch/powerpc/include/arch/elf.h
> @@ -4,5 +4,7 @@
> #define _OBJTOOL_ARCH_ELF
>
> #define R_NONE R_PPC_NONE
> +#define R_ABS64 R_PPC64_ADDR64
> +#define R_ABS32 R_PPC_ADDR32
>
> #endif /* _OBJTOOL_ARCH_ELF */
