Commit 3eee6067 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf dwarf-regs: Add get_dwarf_regnum() 



The get_dwarf_regnum() returns a DWARF register number from a register
name string according to the psABI.  Also add two pseudo encodings of
DWARF_REG_PC which is a register that are used by PC-relative addressing
and DWARF_REG_FB which is a frame base register.  They need to be
handled in a special way.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-3-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 60cb19b4

tools/perf/arch/x86/util/dwarf-regs.c

+38 −0
Original line number Diff line number Diff line
@@ -113,3 +113,41 @@ int regs_query_register_offset(const char *name) 
			return roff->offset;

	return -EINVAL;

}



struct dwarf_regs_idx {

	const char *name;

	int idx;

};



static const struct dwarf_regs_idx x86_regidx_table[] = {

	{ "rax", 0 }, { "eax", 0 }, { "ax", 0 }, { "al", 0 },

	{ "rdx", 1 }, { "edx", 1 }, { "dx", 1 }, { "dl", 1 },

	{ "rcx", 2 }, { "ecx", 2 }, { "cx", 2 }, { "cl", 2 },

	{ "rbx", 3 }, { "edx", 3 }, { "bx", 3 }, { "bl", 3 },

	{ "rsi", 4 }, { "esi", 4 }, { "si", 4 }, { "sil", 4 },

	{ "rdi", 5 }, { "edi", 5 }, { "di", 5 }, { "dil", 5 },

	{ "rbp", 6 }, { "ebp", 6 }, { "bp", 6 }, { "bpl", 6 },

	{ "rsp", 7 }, { "esp", 7 }, { "sp", 7 }, { "spl", 7 },

	{ "r8", 8 }, { "r8d", 8 }, { "r8w", 8 }, { "r8b", 8 },

	{ "r9", 9 }, { "r9d", 9 }, { "r9w", 9 }, { "r9b", 9 },

	{ "r10", 10 }, { "r10d", 10 }, { "r10w", 10 }, { "r10b", 10 },

	{ "r11", 11 }, { "r11d", 11 }, { "r11w", 11 }, { "r11b", 11 },

	{ "r12", 12 }, { "r12d", 12 }, { "r12w", 12 }, { "r12b", 12 },

	{ "r13", 13 }, { "r13d", 13 }, { "r13w", 13 }, { "r13b", 13 },

	{ "r14", 14 }, { "r14d", 14 }, { "r14w", 14 }, { "r14b", 14 },

	{ "r15", 15 }, { "r15d", 15 }, { "r15w", 15 }, { "r15b", 15 },

	{ "rip", DWARF_REG_PC },

};



int get_arch_regnum(const char *name)

{

	unsigned int i;



	if (*name != '%')

		return -EINVAL;



	for (i = 0; i < ARRAY_SIZE(x86_regidx_table); i++)

		if (!strcmp(x86_regidx_table[i].name, name + 1))

			return x86_regidx_table[i].idx;

	return -ENOENT;

}

tools/perf/util/dwarf-regs.c

+34 −0
Original line number Diff line number Diff line
@@ -5,9 +5,12 @@ 
 * Written by: Masami Hiramatsu <mhiramat@kernel.org>

 */



#include <stdlib.h>

#include <string.h>

#include <debug.h>

#include <dwarf-regs.h>

#include <elf.h>

#include <errno.h>

#include <linux/kernel.h>



#ifndef EM_AARCH64
@@ -68,3 +71,34 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine) 
	}

	return NULL;

}



__weak int get_arch_regnum(const char *name __maybe_unused)

{

	return -ENOTSUP;

}



/* Return DWARF register number from architecture register name */

int get_dwarf_regnum(const char *name, unsigned int machine)

{

	char *regname = strdup(name);

	int reg = -1;

	char *p;



	if (regname == NULL)

		return -EINVAL;



	/* For convenience, remove trailing characters */

	p = strpbrk(regname, " ,)");

	if (p)

		*p = '\0';



	switch (machine) {

	case EM_NONE:	/* Generic arch - use host arch */

		reg = get_arch_regnum(regname);

		break;

	default:

		pr_err("ELF MACHINE %x is not supported.\n", machine);

	}

	free(regname);

	return reg;

}

tools/perf/util/include/dwarf-regs.h

+19 −0
Original line number Diff line number Diff line
@@ -2,6 +2,9 @@ 
#ifndef _PERF_DWARF_REGS_H_

#define _PERF_DWARF_REGS_H_



#define DWARF_REG_PC  0xd3af9c /* random number */

#define DWARF_REG_FB  0xd3affb /* random number */



#ifdef HAVE_DWARF_SUPPORT

const char *get_arch_regstr(unsigned int n);

/*
@@ -10,6 +13,22 @@ const char *get_arch_regstr(unsigned int n); 
 * machine: ELF machine signature (EM_*)

 */

const char *get_dwarf_regstr(unsigned int n, unsigned int machine);



int get_arch_regnum(const char *name);

/*

 * get_dwarf_regnum - Returns DWARF regnum from register name

 * name: architecture register name

 * machine: ELF machine signature (EM_*)

 */

int get_dwarf_regnum(const char *name, unsigned int machine);



#else /* HAVE_DWARF_SUPPORT */



static inline int get_dwarf_regnum(const char *name __maybe_unused,

				   unsigned int machine __maybe_unused)

{

	return -1;

}

#endif



#ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET