sparc: Implement backtrace on top <unwind-link.h>

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Florian Weimer 2021-03-01 15:56:36 +01:00
parent 6563d544db
commit 600fe89cb1

View File

@ -21,9 +21,8 @@
#include <stddef.h>
#include <sysdep.h>
#include <sys/trap.h>
#include <dlfcn.h>
#include <unwind.h>
#include <backtrace.h>
#include <unwind-link.h>
struct layout
{
@ -36,45 +35,12 @@ struct layout
struct trace_arg
{
void **array;
struct unwind_link *unwind_link;
_Unwind_Word cfa;
int cnt;
int size;
};
#ifdef SHARED
static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
static _Unwind_Word (*unwind_getcfa) (struct _Unwind_Context *);
static void *libgcc_handle;
/* Dummy version in case libgcc_s does not contain the real code. */
static _Unwind_Word
dummy_getcfa (struct _Unwind_Context *ctx __attribute__ ((unused)))
{
return 0;
}
static void
init (void)
{
libgcc_handle = __libc_dlopen ("libgcc_s.so.1");
if (libgcc_handle == NULL)
return;
unwind_backtrace = __libc_dlsym (libgcc_handle, "_Unwind_Backtrace");
unwind_getip = __libc_dlsym (libgcc_handle, "_Unwind_GetIP");
if (unwind_getip == NULL)
unwind_backtrace = NULL;
unwind_getcfa = (__libc_dlsym (libgcc_handle, "_Unwind_GetCFA")
?: dummy_getcfa);
}
#else
# define unwind_backtrace _Unwind_Backtrace
# define unwind_getip _Unwind_GetIP
# define unwind_getcfa _Unwind_GetCFA
#endif
static _Unwind_Reason_Code
backtrace_helper (struct _Unwind_Context *ctx, void *a)
{
@ -85,11 +51,12 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a)
Skip it. */
if (arg->cnt != -1)
{
ip = unwind_getip (ctx);
ip = UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetIP) (ctx);
arg->array[arg->cnt] = (void *) ip;
/* Check whether we make any progress. */
_Unwind_Word cfa = unwind_getcfa (ctx);
_Unwind_Word cfa
= UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetCFA) (ctx);
if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt]
&& cfa == arg->cfa)
@ -104,23 +71,19 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a)
int
__backtrace (void **array, int size)
{
struct trace_arg arg = { .array = array, .cfa = 0, .size = size, .cnt = -1 };
bool use_unwinder;
int count;
struct trace_arg arg =
{
.array = array,
.unwind_link = __libc_unwind_link_get (),
.size = size,
.cnt = -1,
};
if (size <= 0)
return 0;
use_unwinder = true;
#ifdef SHARED
__libc_once_define (static, once);
__libc_once (once, init);
if (unwind_backtrace == NULL)
use_unwinder = false;
#endif
if (use_unwinder == false)
if (arg.unwind_link == NULL)
{
struct layout *current;
unsigned long fp, i7;
@ -145,7 +108,8 @@ __backtrace (void **array, int size)
}
else
{
unwind_backtrace (backtrace_helper, &arg);
UNWIND_LINK_PTR (arg.unwind_link, _Unwind_Backtrace)
(backtrace_helper, &arg);
/* _Unwind_Backtrace seems to put NULL address above
_start. Fix it up here. */