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fptr.c (_dl_read_access_allowed): Change argument to unsigned int.

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* config/pa/fptr.c (_dl_read_access_allowed): Change argument to
	unsigned int.  Adjust callers.
	(__canonicalize_funcptr_for_compare): Change plabel type to volatile
	unsigned int *.  Load relocation offset before function pointer.
	Add barrier to ensure ordering.

From-SVN: r277016
This commit is contained in:
John David Anglin 2019-10-15 22:20:12 +00:00
parent cecc781c19
commit 68397a8ff9
2 changed files with 18 additions and 6 deletions
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8
libgcc/ChangeLog
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@ -1,3 +1,11 @@
2019-10-15 John David Anglin <danglin@gcc.gnu.org>
* config/pa/fptr.c (_dl_read_access_allowed): Change argument to
unsigned int. Adjust callers.
(__canonicalize_funcptr_for_compare): Change plabel type to volatile
unsigned int *. Load relocation offset before function pointer.
Add barrier to ensure ordering.
2019-10-12 John David Anglin <danglin@gcc.gnu.org>
* config/pa/lib2funcs.S (__gcc_plt_call): Load branch target to %r21.

16
libgcc/config/pa/fptr.c
View File

@ -53,7 +53,7 @@ typedef int (*fixup_t) (struct link_map *, unsigned int);
extern unsigned int _GLOBAL_OFFSET_TABLE_;
static inline int
_dl_read_access_allowed (unsigned int *addr)
_dl_read_access_allowed (unsigned int addr)
{
int result;
@ -76,7 +76,8 @@ __canonicalize_funcptr_for_compare (fptr_t fptr)
{
static unsigned int fixup_plabel[2] __attribute__((used));
fixup_t fixup;
unsigned int *got, *iptr, *plabel;
volatile unsigned int *plabel;
unsigned int *got, *iptr, reloc_offset;
int i;
/* -1 and page 0 are special. -1 is used in crtend to mark the end of
@ -91,17 +92,20 @@ __canonicalize_funcptr_for_compare (fptr_t fptr)
to the entry of the PLT stub just before the global offset table.
The second word in the plabel contains the relocation offset for the
function. */
plabel = (unsigned int *) ((unsigned int) fptr & ~3);
if (!_dl_read_access_allowed (plabel))
plabel = (volatile unsigned int *) ((unsigned int) fptr & ~3);
if (!_dl_read_access_allowed ((unsigned int)plabel))
return (unsigned int) fptr;
/* Load first word of candidate descriptor. It should be a pointer
with word alignment and point to memory that can be read. */
got = (unsigned int *) plabel[0];
if (((unsigned int) got & 3) != 0
|| !_dl_read_access_allowed (got))
|| !_dl_read_access_allowed ((unsigned int)got))
return (unsigned int) fptr;
/* We need to load the relocation offset before the function address. */
reloc_offset = plabel[1];
__sync_synchronize();
got = (unsigned int *) (plabel[0] + GOT_FROM_PLT_STUB);
/* Return the address of the function if the plabel has been resolved. */
@ -137,7 +141,7 @@ __canonicalize_funcptr_for_compare (fptr_t fptr)
/* Call fixup to resolve the function address. got[1] contains the
link_map pointer and plabel[1] the relocation offset. */
fixup ((struct link_map *) got[1], plabel[1]);
fixup ((struct link_map *) got[1], reloc_offset);
return plabel[0];
}