Do not leave stray qword on top of stack for interrupts and exceptions

without error code.  Doing so it mis-aligned the stack.

Since the only consumer of the SSE instructions with the alignment
requirements is AES-NI module, and since the FPU context cannot be
accessed in interrupts, the only situation where the alignment matter
are the compat32 syscalls, as reported in the PR.

PR:	229222
Reported and tested by:	 dewayne@heuristicsystems.com.au
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
This commit is contained in:
kib 2018-06-25 11:29:04 +00:00
parent 9dcf52daee
commit e513711c99

View File

@ -187,7 +187,7 @@
movq PCPU(KCR3),%rax
movq %rax,%cr3
movq PCPU(RSP0),%rax
subq $PTI_SIZE,%rax
subq $PTI_SIZE - 8 * (1 - \has_err),%rax
MOVE_STACKS ((PTI_SIZE / 8) - 1 + \has_err)
movq %rax,%rsp
popq %rdx