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[BZ #9750]

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* nscd/mem.c (gc): Use alloca_count to get the real stack usage.
	* include/alloca.h (alloca_account): Define.
	* sysdeps/x86_64/stackinfo.h (stackinfo_get_sp): Define.
	(stackinfo_sub_sp): Define.
This commit is contained in:
Ulrich Drepper 2009-01-29 00:17:57 +00:00
parent 31d322a214
commit fd537e535f
4 changed files with 38 additions and 14 deletions
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6
ChangeLog
View File

@ -1,5 +1,11 @@
2009-01-28 Ulrich Drepper <drepper@redhat.com>
[BZ #9750]
* nscd/mem.c (gc): Use alloca_count to get the real stack usage.
* include/alloca.h (alloca_account): Define.
* sysdeps/x86_64/stackinfo.h (stackinfo_get_sp): Define.
(stackinfo_sub_sp): Define.
* nscd/connections.c (nscd_init): If database file access be
opened check whether this is due to permission problems and bail
in that case.

13
include/alloca.h
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@ -46,4 +46,17 @@ extern int __libc_alloca_cutoff (size_t size) __attribute__ ((const));
__alloca (((len) = (newlen)))
#endif
#if defined stackinfo_get_sp && defined stackinfo_sub_sp
# define alloca_account(size, avar) \
({ void *old__ = stackinfo_get_sp (); \
void *m__ = __alloca (size); \
avar += stackinfo_sub_sp (old__); \
m__; })
#else
# define alloca_account(size, avar) \
({ size_t s__ = (size); \
avar += size__; \
__alloca (size__); })
#endif
#endif

21
nscd/mem.c
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@ -134,12 +134,11 @@ gc (struct database_dyn *db)
stack_used = 0;
size_t nmark = (db->head->first_free / BLOCK_ALIGN + BITS - 1) / BITS;
size_t memory_needed = nmark * sizeof (BITMAP_T);
if (stack_used + memory_needed <= MAX_STACK_USE)
if (__builtin_expect (stack_used + memory_needed <= MAX_STACK_USE, 1))
{
mark = (BITMAP_T *) alloca (memory_needed);
mark = (BITMAP_T *) alloca_account (memory_needed, stack_used);
mark_use_malloc = false;
memset (mark, '\0', memory_needed);
stack_used += memory_needed;
}
else
{
@ -153,19 +152,17 @@ gc (struct database_dyn *db)
struct hashentry **he;
struct hashentry **he_data;
bool he_use_malloc;
if (stack_used + memory_needed <= MAX_STACK_USE)
if (__builtin_expect (stack_used + memory_needed <= MAX_STACK_USE, 1))
{
he = alloca (db->head->nentries * sizeof (struct hashentry *));
he_data = alloca (db->head->nentries * sizeof (struct hashentry *));
he = alloca_account (memory_needed, stack_used);
he_use_malloc = false;
stack_used += memory_needed;
}
else
{
he = xmalloc (memory_needed);
he_data = &he[db->head->nentries];
he_use_malloc = true;
}
he_data = &he[db->head->nentries];
size_t cnt = 0;
for (size_t idx = 0; idx < db->head->module; ++idx)
@ -373,11 +370,9 @@ gc (struct database_dyn *db)
ref_t disp = off_alloc - off_free;
struct moveinfo *new_move;
if (stack_used + sizeof (*new_move) <= MAX_STACK_USE)
{
new_move = alloca (sizeof (*new_move));
stack_used += sizeof (*new_move);
}
if (__builtin_expect (stack_used + sizeof (*new_move) <= MAX_STACK_USE,
1))
new_move = alloca_account (sizeof (*new_move), stack_used);
else
new_move = obstack_alloc (&ob, sizeof (*new_move));
new_move->from = db->data + off_alloc;

12
sysdeps/x86_64/stackinfo.h
View File

@ -1,4 +1,4 @@
/* Copyright (C) 2001 Free Software Foundation, Inc.
/* Copyright (C) 2001, 2009 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -25,4 +25,14 @@
/* On x86_64 the stack grows down. */
#define _STACK_GROWS_DOWN 1
/* Access to the stack pointer. The macros are used in alloca_account
for which they need to act as barriers as well, hence the additional
(unnecessary) parameters. */
#define stackinfo_get_sp() \
({ void *p__; asm volatile ("mov %%rsp, %0" : "=r" (p__)); p__; })
#define stackinfo_sub_sp(ptr) \
({ ptrdiff_t d__; \
asm volatile ("sub %%rsp, %0" : "=r" (d__) : "0" (ptr)); \
d__; })
#endif /* stackinfo.h */