Re: [PATCH v3 16/16] objtool/powerpc: Add --mcount specific implementation
From: Christophe Leroy <hidden>
Date: 2022-09-13 10:01:00
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lkml
Le 12/09/2022 à 10:20, Sathvika Vasireddy a écrit :
quoted hunk ↗ jump to hunk
This patch enables objtool --mcount on powerpc, and adds implementation specific to powerpc. Signed-off-by: Sathvika Vasireddy <redacted> --- arch/powerpc/Kconfig | 1 + tools/objtool/arch/powerpc/decode.c | 16 ++++++++++++++++ tools/objtool/arch/powerpc/include/arch/elf.h | 2 ++ 3 files changed, 19 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_REGSdiff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c index dcd0975cad6b..ea2b1968f0ee 100644 --- a/tools/objtool/arch/powerpc/decode.c +++ b/tools/objtool/arch/powerpc/decode.c@@ -9,6 +9,11 @@ #include <objtool/builtin.h> #include <objtool/endianness.h> +int arch_ftrace_match(char *name) +{ + return !strcmp(name, "_mcount"); +} + unsigned long arch_dest_reloc_offset(int addend) { return addend;@@ -50,6 +55,17 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec typ = INSN_OTHER; imm = 0; + switch (opcode) { + case 18: /* b[l][a] */ + if (insn & 1) /* bl[a] */ + typ = INSN_CALL;
If you also handle bla, you need to take it into account in the address calculation. When second AA bit is set you must calculate the address accordingly. See https://patchwork.ozlabs.org/project/linuxppc-dev/patch/ebe11b73d1015a17034a2c4bedf093fa57f5d29f.1662032631.git.christophe.leroy@csgroup.eu/
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+ + imm = insn & 0x3fffffc; + if (imm & 0x2000000) + imm -= 0x4000000; + break; + } + if (opcode == 1) *len = 8; elsediff --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 */