Make sure the first argument to the user function is 16-byte aligned.

Submitted by:	tegge
This commit is contained in:
Daniel Eischen 2004-12-05 21:22:08 +00:00
parent 405a104ec0
commit 6c68cb596e
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=138403

View File

@ -93,7 +93,7 @@ __makecontext(ucontext_t *ucp, void (*start)(void), int argc, ...)
*
* _ctx_start() - context start wrapper
* start() - user start routine
* arg1
* arg1 - first argument, aligned(16)
* ...
* argn
* ucp - this context, %ebp points here
@ -110,15 +110,17 @@ __makecontext(ucontext_t *ucp, void (*start)(void), int argc, ...)
* (uc_link != 0) or exit the program (uc_link == 0).
*/
stack_top = (char *)(ucp->uc_stack.ss_sp +
ucp->uc_stack.ss_size - sizeof(double));
stack_top = (char *)ALIGN(stack_top);
ucp->uc_stack.ss_size - sizeof(intptr_t));
/*
* Adjust top of stack to allow for 3 pointers (return
* address, _ctx_start, and ucp) and argc arguments.
* We allow the arguments to be pointers also.
* We allow the arguments to be pointers also. The first
* argument to the user function must be properly aligned.
*/
stack_top = stack_top - (sizeof(intptr_t) * (3 + argc));
stack_top = stack_top - (sizeof(intptr_t) * (1 + argc));
stack_top = (char *)((unsigned)stack_top & ~15);
stack_top = stack_top - (2 * sizeof(intptr_t));
argp = (intptr_t *)stack_top;
/*