m68k: 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 fd19b84640
commit 6563d544db

View File

@ -16,52 +16,18 @@
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;
void *lastfp, *lastsp;
};
#ifdef SHARED
static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
static _Unwind_Ptr (*unwind_getcfa) (struct _Unwind_Context *);
static _Unwind_Ptr (*unwind_getgr) (struct _Unwind_Context *, int);
static void *libgcc_handle;
static void
init (void)
{
libgcc_handle = __libc_dlopen ("libgcc_s.so.2");
if (libgcc_handle == NULL)
return;
unwind_backtrace = __libc_dlsym (libgcc_handle, "_Unwind_Backtrace");
unwind_getip = __libc_dlsym (libgcc_handle, "_Unwind_GetIP");
unwind_getcfa = __libc_dlsym (libgcc_handle, "_Unwind_GetCFA");
unwind_getgr = __libc_dlsym (libgcc_handle, "_Unwind_GetGR");
if (unwind_getip == NULL || unwind_getgr == NULL || unwind_getcfa == NULL)
{
unwind_backtrace = NULL;
__libc_dlclose (libgcc_handle);
libgcc_handle = NULL;
}
}
#else
# define unwind_backtrace _Unwind_Backtrace
# define unwind_getip _Unwind_GetIP
# define unwind_getcfa _Unwind_GetCFA
# define unwind_getgr _Unwind_GetGR
#endif
static _Unwind_Reason_Code
backtrace_helper (struct _Unwind_Context *ctx, void *a)
{
@ -70,13 +36,16 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a)
/* We are first called with address in the __backtrace function.
Skip it. */
if (arg->cnt != -1)
arg->array[arg->cnt] = (void *) unwind_getip (ctx);
arg->array[arg->cnt]
= (void *) UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetIP) (ctx);
if (++arg->cnt == arg->size)
return _URC_END_OF_STACK;
/* %fp is DWARF2 register 14 on M68K. */
arg->lastfp = (void *) unwind_getgr (ctx, 14);
arg->lastsp = (void *) unwind_getcfa (ctx);
arg->lastfp
= (void *) UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetGR) (ctx, 14);
arg->lastsp
= (void *) UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetCFA) (ctx);
return _URC_NO_REASON;
}
@ -110,20 +79,19 @@ struct layout
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;
@ -146,17 +114,3 @@ __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