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| author | bde <bde@FreeBSD.org> | 2002-05-05 03:19:48 +0000 |
|---|---|---|
| committer | bde <bde@FreeBSD.org> | 2002-05-05 03:19:48 +0000 |
| commit | e129a7f152187872c6eb5efb7ecc6c8b82013088 (patch) | |
| tree | 61a9fc3ffd6c6fedff283fff2aaf575dcaaa91eb | |
| parent | 9fdf8815bfb582cb87f0fa996a7d5f0caeceeaed (diff) | |
| download | FreeBSD-src-e129a7f152187872c6eb5efb7ecc6c8b82013088.zip FreeBSD-src-e129a7f152187872c6eb5efb7ecc6c8b82013088.tar.gz | |
Fixed checking for VM86 mode in doreti which I broke in rev.1.30. Only
the case of VM86 calls from the kernel was broken, so this bug was not
a security hole.
PR: 36710
Submitted by: David Xu <davidx@viasoft.com.cn> (version for RELENG_4)
MFC after: 3 days
| -rw-r--r-- | sys/i386/isa/ipl.s | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/sys/i386/isa/ipl.s b/sys/i386/isa/ipl.s index 78527f6..6fba56f 100644 --- a/sys/i386/isa/ipl.s +++ b/sys/i386/isa/ipl.s @@ -57,13 +57,19 @@ doreti: FAKE_MCOUNT(bintr) /* init "from" bintr -> doreti */ doreti_next: - /* Check if ASTs can be handled now. */ + /* + * Check if ASTs can be handled now. PSL_VM must be checked first + * since segment registers only have an RPL in non-VM86 mode. + */ + testl $PSL_VM,TF_EFLAGS(%esp) /* are we in vm86 mode? */ + jz doreti_notvm86 + cmpl $1,in_vm86call /* are we in a vm86 call? */ + jne doreti_ast /* can handle ASTs now if not */ + jmp doreti_exit + +doreti_notvm86: testb $SEL_RPL_MASK,TF_CS(%esp) /* are we in user mode? */ - jne doreti_ast /* yes, do it now. */ - testl $PSL_VM,TF_EFLAGS(%esp) /* kernel mode */ - je doreti_exit /* and not VM86 mode, defer */ - cmpl $1,in_vm86call /* are we in a VM86 call? */ - je doreti_exit /* no, defer */ + jz doreti_exit /* can't handle ASTs now if not */ doreti_ast: /* |
