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PPC64: fix TOC behavior on process initialization

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Set stack pointer to correct value after thread's stack pointer restore

Restoring new thread's stack pointer caused stack corruption because
restored stack pointer didn't point to callee (cpu_switch) stack frame but
caller stack frame.

As a result we had mysterious errors in caller function (sched_switch).

Solution: simply set stack pointer to correct value

Also, initialize TOC to a valid pointer once the thread is being
created.

Created by:            Patryk Duda <pdk@semihalf.com>
Submitted by:          Wojciech Macek <wma@semihalf.com>
Obtained from:         Semihalf
Reviewed by:           nwhitehorn
Differential revision: https://reviews.freebsd.org/D13947
Sponsored by:          QCM Technologies
This commit is contained in:
wma 2018-01-18 07:42:51 +00:00
parent 6362070dc8
commit b6338c1a07
2 changed files with 4 additions and 0 deletions
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1
sys/powerpc/powerpc/swtch64.S
View File

@ -160,6 +160,7 @@ blocked_loop:
ld %r17,TD_PCB(%r13) /* Get new PCB */
ld %r1,PCB_SP(%r17) /* Load the stack pointer */
addi %r1,%r1,-48 /* Remember about cpu_switch stack frame */
/* Release old thread now that we have a stack pointer set up */
cmpdi %r14,0

3
sys/powerpc/powerpc/vm_machdep.c
View File

@ -190,6 +190,9 @@ cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
cf = (struct callframe *)td->td_pcb->pcb_sp;
#if defined(__powerpc64__) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
cf->cf_toc = ((register_t *)func)[1];
#endif
cf->cf_func = (register_t)func;
cf->cf_arg0 = (register_t)arg;
}