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For the amd64 we need to do some extra stack alignment fixups. Otherwise

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we can end up with some threads with a non-16-byte-aligned stack.  This
causes some interesting side effects, including general protection
faults leading to a SIGBUS when doing floating point or varargs.  This
should be just a verbose NOP for the other platforms.

Approved by:  re (scottl)
This commit is contained in:
Peter Wemm 2003-12-03 06:54:40 +00:00
parent 20109fa046
commit 29f2f145e4
3 changed files with 27 additions and 6 deletions
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11
lib/libc_r/uthread/uthread_create.c
View File

@ -73,6 +73,9 @@ _pthread_create(pthread_t *thread, const pthread_attr_t *attr,
pthread_t new_thread;
pthread_attr_t pattr;
void *stack;
#if !defined(__ia64__)
u_long stackp;
#endif
if (thread == NULL)
return(EINVAL);
@ -145,10 +148,12 @@ _pthread_create(pthread_t *thread, const pthread_attr_t *attr,
SET_RETURN_ADDR_JB(new_thread->ctx.jb, _thread_start);
#if !defined(__ia64__)
stackp = (long)new_thread->stack + pattr->stacksize_attr - sizeof(double);
#if defined(__amd64__)
stackp &= ~0xFUL;
#endif
/* The stack starts high and builds down: */
SET_STACK_JB(new_thread->ctx.jb,
(long)new_thread->stack + pattr->stacksize_attr
- sizeof(double));
SET_STACK_JB(new_thread->ctx.jb, stackp);
#else
SET_STACK_JB(new_thread->ctx.jb,
(long)new_thread->stack, pattr->stacksize_attr);

10
lib/libc_r/uthread/uthread_init.c
View File

@ -208,6 +208,9 @@ _thread_init(void)
size_t len;
int mib[2];
int sched_stack_size; /* Size of scheduler stack. */
#if !defined(__ia64__)
u_long stackp;
#endif
struct clockinfo clockinfo;
struct sigaction act;
@ -374,8 +377,11 @@ _thread_init(void)
/* Setup the context for the scheduler: */
_setjmp(_thread_kern_sched_jb);
#if !defined(__ia64__)
SET_STACK_JB(_thread_kern_sched_jb, _thread_kern_sched_stack +
sched_stack_size - sizeof(double));
stackp = (long)_thread_kern_sched_stack + sched_stack_size - sizeof(double);
#if defined(__amd64__)
stackp &= ~0xFUL;
#endif
SET_STACK_JB(_thread_kern_sched_jb, stackp);
#else
SET_STACK_JB(_thread_kern_sched_jb, _thread_kern_sched_stack,
sched_stack_size);

12
lib/libc_r/uthread/uthread_sig.c
View File

@ -1048,13 +1048,20 @@ thread_sigframe_add(struct pthread *thread, int sig, int has_args)
* Leave a little space on the stack and round down to the
* nearest aligned word:
*/
#if defined(__amd64__)
stackp -= 128; /* Skip over 128 byte red-zone */
#endif
stackp -= sizeof(double);
#if defined(__amd64__)
stackp &= ~0xFUL;
#else
stackp &= ~0x3UL;
#endif
#endif
/* Allocate room on top of the stack for a new signal frame: */
stackp -= sizeof(struct pthread_signal_frame);
#if defined(__ia64__)
#if defined(__ia64__) || defined(__amd64__)
stackp &= ~0xFUL;
#endif
@ -1087,6 +1094,9 @@ thread_sigframe_add(struct pthread *thread, int sig, int has_args)
*/
#if !defined(__ia64__)
stackp -= sizeof(double);
#if defined(__amd64__)
stackp &= ~0xFUL;
#endif
#endif
_setjmp(thread->ctx.jb);
#if !defined(__ia64__)