[RFC PATCH 3/3] objtool/mcount: Add powerpc specific functions
From: Sathvika Vasireddy
Date: Fri Mar 18 2022 - 06:54:17 EST
This patch adds powerpc specific functions required for
'objtool mcount' to work, and enables mcount for ppc.
Signed-off-by: Sathvika Vasireddy <sv@xxxxxxxxxxxxx>
---
arch/powerpc/Kconfig | 1 +
tools/objtool/Makefile | 4 ++
tools/objtool/arch/powerpc/Build | 1 +
tools/objtool/arch/powerpc/decode.c | 51 +++++++++++++++++++
.../arch/powerpc/include/arch/cfi_regs.h | 37 ++++++++++++++
tools/objtool/arch/powerpc/include/arch/elf.h | 8 +++
tools/objtool/utils.c | 28 ++++++++--
7 files changed, 125 insertions(+), 5 deletions(-)
create mode 100644 tools/objtool/arch/powerpc/Build
create mode 100644 tools/objtool/arch/powerpc/decode.c
create mode 100644 tools/objtool/arch/powerpc/include/arch/cfi_regs.h
create mode 100644 tools/objtool/arch/powerpc/include/arch/elf.h
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b779603978e1..5ddafd3ce210 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -225,6 +225,7 @@ config PPC
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_NMI if PERF_EVENTS || (PPC64 && PPC_BOOK3S)
select HAVE_OPTPROBES
+ select HAVE_OBJTOOL_MCOUNT
select HAVE_PERF_EVENTS
select HAVE_PERF_EVENTS_NMI if PPC64
select HAVE_PERF_REGS
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 8404cf696954..06a9fcb4a0a3 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -49,6 +49,10 @@ ifeq ($(SRCARCH),x86)
SUBCMD_MCOUNT := y
endif
+ifeq ($(SRCARCH),powerpc)
+ SUBCMD_MCOUNT := y
+endif
+
export SUBCMD_CHECK SUBCMD_ORC SUBCMD_MCOUNT
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include
diff --git a/tools/objtool/arch/powerpc/Build b/tools/objtool/arch/powerpc/Build
new file mode 100644
index 000000000000..3ff1f00c6a47
--- /dev/null
+++ b/tools/objtool/arch/powerpc/Build
@@ -0,0 +1 @@
+objtool-y += decode.o
diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
new file mode 100644
index 000000000000..58988f88b315
--- /dev/null
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <objtool/check.h>
+#include <objtool/elf.h>
+#include <objtool/arch.h>
+#include <objtool/warn.h>
+#include <objtool/builtin.h>
+
+int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
+ unsigned long offset, unsigned int maxlen,
+ unsigned int *len, enum insn_type *type,
+ unsigned long *immediate,
+ struct list_head *ops_list)
+{
+ u32 insn;
+ unsigned int opcode;
+ u64 imm;
+
+ *immediate = imm = 0;
+ memcpy(&insn, sec->data->d_buf+offset, 4);
+ *len = 4;
+ *type = INSN_OTHER;
+
+ opcode = (insn >> 26);
+
+ switch (opcode) {
+ case 18: /* bl */
+ *type = INSN_CALL;
+ break;
+ }
+ *immediate = imm;
+ return 0;
+}
+
+unsigned long arch_dest_reloc_offset(int addend)
+{
+ return addend;
+}
+
+unsigned long arch_jump_destination(struct instruction *insn)
+{
+ return insn->offset + insn->immediate;
+}
+
+const char *arch_nop_insn(int len)
+{
+ return NULL;
+}
diff --git a/tools/objtool/arch/powerpc/include/arch/cfi_regs.h b/tools/objtool/arch/powerpc/include/arch/cfi_regs.h
new file mode 100644
index 000000000000..1369176c8a94
--- /dev/null
+++ b/tools/objtool/arch/powerpc/include/arch/cfi_regs.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _OBJTOOL_CFI_REGS_H
+#define _OBJTOOL_CFI_REGS_H
+
+#define CFI_SP 1
+#define CFI_TOC 2
+#define CFI_R3 3
+#define CFI_R4 4
+#define CFI_R5 5
+#define CFI_R6 6
+#define CFI_R7 7
+#define CFI_R8 8
+#define CFI_R9 9
+#define CFI_R10 10
+#define CFI_R14 14
+#define CFI_R15 15
+#define CFI_R16 16
+#define CFI_R17 17
+#define CFI_R18 18
+#define CFI_R19 19
+#define CFI_R20 20
+#define CFI_R21 21
+#define CFI_R22 22
+#define CFI_R23 23
+#define CFI_R24 24
+#define CFI_R25 25
+#define CFI_R26 26
+#define CFI_R27 27
+#define CFI_R28 28
+#define CFI_R29 29
+#define CFI_R30 30
+#define CFI_R31 31
+#define CFI_LR 32
+#define CFI_NUM_REGS 33
+
+#endif
diff --git a/tools/objtool/arch/powerpc/include/arch/elf.h b/tools/objtool/arch/powerpc/include/arch/elf.h
new file mode 100644
index 000000000000..3c8ebb7d2a6b
--- /dev/null
+++ b/tools/objtool/arch/powerpc/include/arch/elf.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _OBJTOOL_ARCH_ELF
+#define _OBJTOOL_ARCH_ELF
+
+#define R_NONE R_PPC_NONE
+
+#endif /* _OBJTOOL_ARCH_ELF */
diff --git a/tools/objtool/utils.c b/tools/objtool/utils.c
index d1fc6a123a6e..c9c14fa0dfd7 100644
--- a/tools/objtool/utils.c
+++ b/tools/objtool/utils.c
@@ -179,11 +179,29 @@ int create_mcount_loc_sections(struct objtool_file *file)
loc = (unsigned long *)sec->data->d_buf + idx;
memset(loc, 0, sizeof(unsigned long));
- if (elf_add_reloc_to_insn(file->elf, sec,
- idx * sizeof(unsigned long),
- R_X86_64_64,
- insn->sec, insn->offset))
- return -1;
+ if (file->elf->ehdr.e_machine == EM_X86_64) {
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(unsigned long),
+ R_X86_64_64,
+ insn->sec, insn->offset))
+ return -1;
+ }
+
+ if (file->elf->ehdr.e_machine == EM_PPC64) {
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(unsigned long),
+ R_PPC64_ADDR64,
+ insn->sec, insn->offset))
+ return -1;
+ }
+
+ if (file->elf->ehdr.e_machine == EM_PPC) {
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(unsigned long),
+ R_PPC_ADDR32,
+ insn->sec, insn->offset))
+ return -1;
+ }
idx++;
}
--
2.31.1