[03/10] arm: Implement backtrace on top of <unwind-link.h>
Commit Message
---
sysdeps/arm/backtrace.c | 77 +++++++++++------------------------------
1 file changed, 20 insertions(+), 57 deletions(-)
Comments
On 2/17/21 11:02 AM, Florian Weimer via Libc-alpha wrote:
LGTM. The arm version.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> ---
> sysdeps/arm/backtrace.c | 77 +++++++++++------------------------------
> 1 file changed, 20 insertions(+), 57 deletions(-)
>
> diff --git a/sysdeps/arm/backtrace.c b/sysdeps/arm/backtrace.c
> index 3ed975fb96..193f2410ba 100644
> --- a/sysdeps/arm/backtrace.c
> +++ b/sysdeps/arm/backtrace.c
> @@ -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 };
> -
> - if (size <= 0)
> - return 0;
> -
> -#ifdef SHARED
> - __libc_once_define (static, once);
> + struct trace_arg arg =
> + {
> + .array = array,
> + .unwind_link = __libc_unwind_link_get (),
> + .size = size,
> + .cnt = -1
> + };
>
> - __libc_once (once, init);
> - if (unwind_backtrace == NULL)
> + if (size <= 0 || arg.unwind_link == 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
>
@@ -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 };
-
- if (size <= 0)
- return 0;
-
-#ifdef SHARED
- __libc_once_define (static, once);
+ struct trace_arg arg =
+ {
+ .array = array,
+ .unwind_link = __libc_unwind_link_get (),
+ .size = size,
+ .cnt = -1
+ };
- __libc_once (once, init);
- if (unwind_backtrace == NULL)
+ if (size <= 0 || arg.unwind_link == 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