linux/tools/perf/arch/x86/tests/dwarf-unwind.c
Ian Rogers 0fb0d615f3 perf test: Initialize memory in dwarf-unwind
Avoid a false positive caused by assembly code in arch/x86.

In tests, zero the perf_event to avoid uninitialized memory uses.

Warnings were caught using clang with -fsanitize=memory.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20200530082015.39162-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-06-01 12:24:23 -03:00

73 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include "perf_regs.h"
#include "thread.h"
#include "map.h"
#include "maps.h"
#include "event.h"
#include "debug.h"
#include "tests/tests.h"
#include "arch-tests.h"
#define STACK_SIZE 8192
static int sample_ustack(struct perf_sample *sample,
struct thread *thread, u64 *regs)
{
struct stack_dump *stack = &sample->user_stack;
struct map *map;
unsigned long sp;
u64 stack_size, *buf;
buf = malloc(STACK_SIZE);
if (!buf) {
pr_debug("failed to allocate sample uregs data\n");
return -1;
}
sp = (unsigned long) regs[PERF_REG_X86_SP];
map = maps__find(thread->maps, (u64)sp);
if (!map) {
pr_debug("failed to get stack map\n");
free(buf);
return -1;
}
stack_size = map->end - sp;
stack_size = stack_size > STACK_SIZE ? STACK_SIZE : stack_size;
memcpy(buf, (void *) sp, stack_size);
stack->data = (char *) buf;
stack->size = stack_size;
return 0;
}
int test__arch_unwind_sample(struct perf_sample *sample,
struct thread *thread)
{
struct regs_dump *regs = &sample->user_regs;
u64 *buf;
buf = malloc(sizeof(u64) * PERF_REGS_MAX);
if (!buf) {
pr_debug("failed to allocate sample uregs data\n");
return -1;
}
#ifdef MEMORY_SANITIZER
/*
* Assignments to buf in the assembly function perf_regs_load aren't
* seen by memory sanitizer. Zero the memory to convince memory
* sanitizer the memory is initialized.
*/
memset(buf, 0, sizeof(u64) * PERF_REGS_MAX);
#endif
perf_regs_load(buf);
regs->abi = PERF_SAMPLE_REGS_ABI;
regs->regs = buf;
regs->mask = PERF_REGS_MASK;
return sample_ustack(sample, thread, buf);
}