From 7f12ebe58305d37fd1f8fb5583bf046c1f0bf51f Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Mon, 25 Jun 2018 11:29:04 +0000 Subject: [PATCH] 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 --- sys/amd64/include/asmacros.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/amd64/include/asmacros.h b/sys/amd64/include/asmacros.h index 11f500267d7e..c4042fa65602 100644 --- a/sys/amd64/include/asmacros.h +++ b/sys/amd64/include/asmacros.h @@ -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