Clean up setjmp use in dl-error.c.

This commit is contained in:
Roland McGrath 2013-12-16 14:09:52 -08:00
parent ff362e5b93
commit eacfdfbfad
2 changed files with 50 additions and 32 deletions

View File

@ -1,3 +1,13 @@
2013-12-16 Roland McGrath <roland@hack.frob.com>
* elf/dl-error.c (struct catch): Add new member `errcode'. Add a
level of indirection to members `objname', `errstring', `malloced'.
(_dl_signal_error): Store through pointers in *LCATCH rather modifying
*LCATCH itself. Set *LCATCH->errcode to ERRCODE rather than passing
it as the __longjmp argument (just pass 1 instead).
(_dl_catch_error): Initialize C with argument pointers and address of
volatile local ERRCODE rather than copying values out of C at return.
2013-12-16 Joseph Myers <joseph@codesourcery.com>
* math/auto-libm-test-in: Add tests of atan2, hypot and pow.

View File

@ -28,10 +28,11 @@
_dl_signal_error. */
struct catch
{
const char *objname; /* Object/File name. */
const char *errstring; /* Error detail filled in here. */
bool malloced; /* Nonzero if the string is malloced
const char **objname; /* Object/File name. */
const char **errstring; /* Error detail filled in here. */
bool *malloced; /* Nonzero if the string is malloced
by the libc malloc. */
volatile int *errcode; /* Return value of _dl_signal_error. */
jmp_buf env; /* longjmp here on error. */
};
@ -86,33 +87,36 @@ _dl_signal_error (int errcode, const char *objname, const char *occation,
size_t len_objname = strlen (objname) + 1;
size_t len_errstring = strlen (errstring) + 1;
lcatch->errstring = (char *) malloc (len_objname + len_errstring);
if (lcatch->errstring != NULL)
char *errstring_copy = malloc (len_objname + len_errstring);
if (errstring_copy != NULL)
{
/* Make a copy of the object file name and the error string. */
lcatch->objname = memcpy (__mempcpy ((char *) lcatch->errstring,
errstring, len_errstring),
objname, len_objname);
*lcatch->objname = memcpy (__mempcpy (errstring_copy,
errstring, len_errstring),
objname, len_objname);
*lcatch->errstring = errstring_copy;
/* If the main executable is relocated it means the libc's malloc
is used. */
bool malloced = true;
#ifdef SHARED
lcatch->malloced = (GL(dl_ns)[LM_ID_BASE]._ns_loaded != NULL
&& (GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_relocated
!= 0));
#else
lcatch->malloced = true;
malloced = (GL(dl_ns)[LM_ID_BASE]._ns_loaded != NULL
&& (GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_relocated != 0));
#endif
*lcatch->malloced = malloced;
}
else
{
/* This is better than nothing. */
lcatch->objname = "";
lcatch->errstring = _dl_out_of_memory;
lcatch->malloced = false;
*lcatch->objname = "";
*lcatch->errstring = _dl_out_of_memory;
*lcatch->malloced = false;
}
*lcatch->errcode = errcode;
/* We do not restore the signal mask because none was saved. */
__longjmp (lcatch->env[0].__jmpbuf, errcode ?: -1);
__longjmp (lcatch->env[0].__jmpbuf, 1);
}
else
{
@ -157,23 +161,29 @@ internal_function
_dl_catch_error (const char **objname, const char **errstring,
bool *mallocedp, void (*operate) (void *), void *args)
{
int errcode;
struct catch *volatile old;
struct catch c;
/* We need not handle `receiver' since setting a `catch' is handled
before it. */
/* Some systems (e.g., SPARC) handle constructors to local variables
inefficient. So we initialize `c' by hand. */
c.errstring = NULL;
/* Only this needs to be marked volatile, because it is the only local
variable that gets changed between the setjmp invocation and the
longjmp call. All others are just set here (before setjmp) and read
in _dl_signal_error (before longjmp). */
volatile int errcode;
struct catch c;
/* Don't use an initializer since we don't need to clear C.env. */
c.objname = objname;
c.errstring = errstring;
c.malloced = mallocedp;
c.errcode = &errcode;
struct catch **const catchp = &CATCH_HOOK;
old = *catchp;
struct catch *const old = *catchp;
*catchp = &c;
/* Do not save the signal mask. */
errcode = __sigsetjmp (c.env, 0);
if (__builtin_expect (errcode, 0) == 0)
if (__builtin_expect (__sigsetjmp (c.env, 0), 0) == 0)
{
*catchp = &c;
(*operate) (args);
*catchp = old;
*objname = NULL;
@ -182,12 +192,10 @@ _dl_catch_error (const char **objname, const char **errstring,
return 0;
}
/* We get here only if we longjmp'd out of OPERATE. */
/* We get here only if we longjmp'd out of OPERATE. _dl_signal_error has
already stored values into *OBJNAME, *ERRSTRING, and *MALLOCEDP. */
*catchp = old;
*objname = c.objname;
*errstring = c.errstring;
*mallocedp = c.malloced;
return errcode == -1 ? 0 : errcode;
return errcode;
}