tools/perf/util/sample.c

Source file repositories/reference/linux-study-clean/tools/perf/util/sample.c

File Facts

System
Linux kernel
Corpus path
tools/perf/util/sample.c
Extension
.c
Size
2956 bytes
Lines
128
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#include "sample.h"
#include "debug.h"
#include "thread.h"
#include <elf.h>
#ifndef EM_CSKY
#define EM_CSKY		252
#endif
#ifndef EM_LOONGARCH
#define EM_LOONGARCH	258
#endif
#include <linux/zalloc.h>
#include <stdlib.h>
#include <string.h>
#include "../../arch/x86/include/asm/insn.h"

void perf_sample__init(struct perf_sample *sample, bool all)
{
	if (all) {
		memset(sample, 0, sizeof(*sample));
	} else {
		sample->evsel = NULL;
		sample->user_regs = NULL;
		sample->intr_regs = NULL;
		sample->merged_callchain = false;
		sample->callchain = NULL;
	}
}

void perf_sample__exit(struct perf_sample *sample)
{
	zfree(&sample->user_regs);
	zfree(&sample->intr_regs);
	if (sample->merged_callchain) {
		zfree(&sample->callchain);
		sample->merged_callchain = false;
	}
}

struct regs_dump *perf_sample__user_regs(struct perf_sample *sample)
{
	if (!sample->user_regs) {
		sample->user_regs = zalloc(sizeof(*sample->user_regs));
		if (!sample->user_regs)
			pr_err("Failure to allocate sample user_regs");
	}
	return sample->user_regs;
}


struct regs_dump *perf_sample__intr_regs(struct perf_sample *sample)
{
	if (!sample->intr_regs) {
		sample->intr_regs = zalloc(sizeof(*sample->intr_regs));
		if (!sample->intr_regs)
			pr_err("Failure to allocate sample intr_regs");
	}
	return sample->intr_regs;
}

static int elf_machine_max_instruction_length(uint16_t e_machine)
{
	switch (e_machine) {
	/* Fixed 4-byte (32-bit) architectures */
	case EM_AARCH64:
	case EM_PPC:
	case EM_PPC64:
	case EM_MIPS:
	case EM_SPARC:
	case EM_SPARCV9:
	case EM_ALPHA:
	case EM_LOONGARCH:
	case EM_PARISC:
	case EM_SH:
		return 4;

	/* Variable length or mixed-mode architectures */
	case EM_ARM:    /* Variable due to Thumb/Thumb-2 */
	case EM_RISCV:  /* Variable due to Compressed (C) extension */
	case EM_CSKY:   /* Variable (16 or 32 bit) */
	case EM_ARC:    /* Variable (ARCompact) */
		return 4;
	case EM_S390:   /* Variable (2, 4, or 6 bytes) */
		return 6;
	case EM_68K:
		return 10;
	case EM_386:
	case EM_X86_64:
		return 15;
	case EM_XTENSA: /* Variable (FLIX) */
		return 16;

Annotation

Implementation Notes