ReceiveTempSMS
/
Sweden-Number
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Fixed race in %gs selector restoring during vm86 mode return. 

Minor cleanups.
This commit is contained in:
Alexandre Julliard 2003-10-30 23:15:56 +00:00
parent 4f47bbc277
commit 0f95d5498d
1 changed files with 44 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

92
dlls/ntdll/signal_i386.c
View File

@ -459,6 +459,17 @@ static inline int get_error_code( const SIGCONTEXT *sigcontext )
#endif
}
/***********************************************************************
* get_signal_stack
*
* Get the base of the signal stack for the current thread.
*/
static inline void *get_signal_stack(void)
{
return NtCurrentTeb()->DeallocationStack;
}
#ifdef __HAVE_VM86
/***********************************************************************
* save_vm86_context
@ -686,24 +697,44 @@ static void restore_context( CONTEXT *context, SIGCONTEXT *sigcontext )
*
* Handler initialization when the full context is not needed.
*/
static void init_handler( const SIGCONTEXT *sigcontext )
static void *init_handler( const SIGCONTEXT *sigcontext )
{
/* restore a proper %fs for the fault handler */
void *stack = (void *)ESP_sig(sigcontext);
/* now restore a proper %fs for the fault handler */
if (!IS_SELECTOR_SYSTEM(CS_sig(sigcontext)) ||
!IS_SELECTOR_SYSTEM(SS_sig(sigcontext))) /* 16-bit mode */
{
/*
* Win16 or DOS protected mode. Note that during switch
* from 16-bit mode to linear mode, CS may be set to system
* segment before FS is restored. Fortunately, in this case
* SS is still non-system segment. This is why both CS and SS
* are checked.
*/
wine_set_fs( signal_fs );
wine_set_gs( NtCurrentTeb()->gs_sel );
stack = (void *)NtCurrentTeb()->cur_stack;
}
#ifdef __HAVE_VM86
else if ((void *)EIP_sig(sigcontext) == vm86_return) /* vm86 mode */
{
/* fetch the saved %fs on the stack */
wine_set_fs( *(unsigned int *)ESP_sig(sigcontext) );
wine_set_gs( NtCurrentTeb()->gs_sel );
unsigned int *int_stack = stack;
/* fetch the saved %fs and %gs from the stack */
wine_set_fs( int_stack[0] );
wine_set_gs( int_stack[1] );
}
#endif /* __HAVE_VM86 */
else /* 32-bit mode, get %fs at time of the fault */
else if ((char *)EIP_sig(sigcontext) == (char *)vm86_return + 2 /* popl %fs */)
{
unsigned int *int_stack = stack;
/* %fs has been popped already but %gs is still on the stack */
#ifdef FS_sig
wine_set_fs( FS_sig(sigcontext) );
#endif
wine_set_gs( int_stack[0] );
}
#endif
else /* 32-bit mode */
{
#ifdef FS_sig
wine_set_fs( FS_sig(sigcontext) );
@ -712,6 +743,7 @@ static void init_handler( const SIGCONTEXT *sigcontext )
wine_set_gs( GS_sig(sigcontext) );
#endif
}
return stack;
}
@ -786,48 +818,12 @@ static EXCEPTION_RECORD *setup_exception( SIGCONTEXT *sigcontext, raise_func fun
gs = wine_get_gs();
#endif
/* now restore a proper %fs for the fault handler */
if (!IS_SELECTOR_SYSTEM(CS_sig(sigcontext)) ||
!IS_SELECTOR_SYSTEM(SS_sig(sigcontext))) /* 16-bit mode */
{
/*
* Win16 or DOS protected mode. Note that during switch
* from 16-bit mode to linear mode, CS may be set to system
* segment before FS is restored. Fortunately, in this case
* SS is still non-system segment. This is why both CS and SS
* are checked.
*/
wine_set_fs( signal_fs );
wine_set_gs( NtCurrentTeb()->gs_sel );
stack = (struct stack_layout *)NtCurrentTeb()->cur_stack;
}
else /* 32-bit mode */
{
stack = (struct stack_layout *)ESP_sig(sigcontext);
#ifdef __HAVE_VM86
if ((void *)EIP_sig(sigcontext) == vm86_return) /* vm86 mode */
{
unsigned int *int_stack = (unsigned int *)stack;
/* fetch the saved %fs and %gs from the stack */
wine_set_fs( int_stack[0] );
wine_set_gs( int_stack[1] );
}
else
#endif
{
#ifdef FS_sig
wine_set_fs( FS_sig(sigcontext) );
#endif
#ifdef GS_sig
wine_set_gs( GS_sig(sigcontext) );
#endif
}
}
stack = init_handler( sigcontext );
/* stack sanity checks */
if ((char *)stack >= (char *)NtCurrentTeb()->DeallocationStack &&
(char *)stack < (char *)NtCurrentTeb()->DeallocationStack + SIGNAL_STACK_SIZE)
if ((char *)stack >= (char *)get_signal_stack() &&
(char *)stack < (char *)get_signal_stack() + SIGNAL_STACK_SIZE)
{
ERR( "nested exception on signal stack in thread %04lx eip %08lx esp %08lx stack %p-%p\n",
GetCurrentThreadId(), EIP_sig(sigcontext), ESP_sig(sigcontext),
@ -1292,7 +1288,7 @@ static int set_handler( int sig, int have_sigaltstack, void (*func)() )
sig_act.ksa_mask = (1 << (SIGINT-1)) |
(1 << (SIGUSR2-1));
/* point to the top of the signal stack */
sig_act.ksa_restorer = (char *)NtCurrentTeb()->DeallocationStack + SIGNAL_STACK_SIZE;
sig_act.ksa_restorer = (char *)get_signal_stack() + SIGNAL_STACK_SIZE;
return wine_sigaction( sig, &sig_act, NULL );
}
#endif /* linux */
@ -1346,7 +1342,7 @@ BOOL SIGNAL_Init(void)
#ifdef HAVE_SIGALTSTACK
struct sigaltstack ss;
ss.ss_sp = NtCurrentTeb()->DeallocationStack;
ss.ss_sp = get_signal_stack();
ss.ss_size = SIGNAL_STACK_SIZE;
ss.ss_flags = 0;
if (!sigaltstack(&ss, NULL)) have_sigaltstack = 1;