arm: Implement backtrace on top of <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 e164d95abf
commit fac75a690e

View File

@ -17,58 +17,36 @@
License along with the GNU C Library. If not, see
<https://www.gnu.org/licenses/>. */
#include <libc-lock.h>
#include <dlfcn.h>
#include <execinfo.h>
#include <stdlib.h>
#include <unwind.h>
#include <unwind-link.h>
struct trace_arg
{
void **array;
struct unwind_link *unwind_link;
int cnt, size;
};
#ifdef SHARED
static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
static _Unwind_VRS_Result (*unwind_vrs_get) (_Unwind_Context *,
_Unwind_VRS_RegClass,
_uw,
_Unwind_VRS_DataRepresentation,
void *);
static void *libgcc_handle;
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_vrs_get = __libc_dlsym (libgcc_handle, "_Unwind_VRS_Get");
if (unwind_vrs_get == NULL)
unwind_backtrace = NULL;
}
/* This function is identical to "_Unwind_GetGR", except that it uses
"unwind_vrs_get" instead of "_Unwind_VRS_Get". */
static inline _Unwind_Word
unwind_getgr (_Unwind_Context *context, int regno)
unwind_getgr (struct unwind_link *unwind_link,
_Unwind_Context *context, int regno)
{
_uw val;
unwind_vrs_get (context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
UNWIND_LINK_PTR (unwind_link, _Unwind_VRS_Get)
(context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
return val;
}
/* This macro is identical to the _Unwind_GetIP macro, except that it
uses "unwind_getgr" instead of "_Unwind_GetGR". */
# define unwind_getip(context) \
(unwind_getgr (context, 15) & ~(_Unwind_Word)1)
#else
# define unwind_backtrace _Unwind_Backtrace
#define unwind_getip(context) \
(unwind_getgr (arg->unwind_link, context, 15) & ~(_Unwind_Word)1)
#else /* !SHARED */
# define unwind_getip _Unwind_GetIP
#endif
@ -89,20 +67,19 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a)
int
__backtrace (void **array, int size)
{
struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
struct trace_arg arg =
{
.array = array,
.unwind_link = __libc_unwind_link_get (),
.size = size,
.cnt = -1
};
if (size <= 0)
if (size <= 0 || arg.unwind_link == NULL)
return 0;
#ifdef SHARED
__libc_once_define (static, once);
__libc_once (once, init);
if (unwind_backtrace == NULL)
return 0;
#endif
unwind_backtrace (backtrace_helper, &arg);
UNWIND_LINK_PTR (arg.unwind_link, _Unwind_Backtrace)
(backtrace_helper, &arg);
if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
--arg.cnt;
@ -110,17 +87,3 @@ __backtrace (void **array, int size)
}
weak_alias (__backtrace, backtrace)
libc_hidden_def (__backtrace)
#ifdef SHARED
/* Free all resources if necessary. */
libc_freeres_fn (free_mem)
{
unwind_backtrace = NULL;
if (libgcc_handle != NULL)
{
__libc_dlclose (libgcc_handle);
libgcc_handle = NULL;
}
}
#endif