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Ensure the userland thread and floating-point state has been saved before

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copying the pcb. These values may have been changed just before the call
to fork and without a call to cpu_switch, where they would have been saved.

Sponsored by:	The FreeBSD Foundation
This commit is contained in:
Andrew Turner 2015-04-15 14:18:25 +00:00
parent 4ee4d5917b
commit 2db317ca85
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=281554
1 changed files with 17 additions and 0 deletions
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17
sys/arm64/arm64/vm_machdep.c
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@ -47,6 +47,10 @@ __FBSDID("$FreeBSD$");
#include <machine/pcb.h>
#include <machine/frame.h>
#ifdef VFP
#include <machine/vfp.h>
#endif
/*
* Finish a fork operation, with process p2 nearly set up.
* Copy and update the pcb, set up the stack so that the child
@ -61,6 +65,19 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
if ((flags & RFPROC) == 0)
return;
if (td1 == curthread) {
/*
* Save the tpidr_el0 and the vfp state, these normally happen
* in cpu_switch, but if userland changes these then forks
* this may not have happened.
*/
td1->td_pcb->pcb_tpidr_el0 = READ_SPECIALREG(tpidr_el0);
#ifdef VFP
if ((td1->td_pcb->pcb_fpflags & PCB_FP_STARTED) != 0)
vfp_save_state(td1);
#endif
}
pcb2 = (struct pcb *)(td2->td_kstack +
td2->td_kstack_pages * PAGE_SIZE) - 1;