Module Name: src
Committed By: maxv
Date: Wed Aug 21 12:33:12 UTC 2019
Modified Files:
src/sys/arch/amd64/amd64: netbsd32_machdep.c
Log Message:
Don't depend on #ifdef USER_LDT in cpu_mcontext32_validate(), but rather on
whether the proc uses a user-set LDT. Same as check_sigcontext32().
To generate a diff of this commit:
cvs rdiff -u -r1.125 -r1.126 src/sys/arch/amd64/amd64/netbsd32_machdep.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/amd64/amd64/netbsd32_machdep.c
diff -u src/sys/arch/amd64/amd64/netbsd32_machdep.c:1.125 src/sys/arch/amd64/amd64/netbsd32_machdep.c:1.126
--- src/sys/arch/amd64/amd64/netbsd32_machdep.c:1.125 Sat Jul 20 18:25:11 2019
+++ src/sys/arch/amd64/amd64/netbsd32_machdep.c Wed Aug 21 12:33:12 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: netbsd32_machdep.c,v 1.125 2019/07/20 18:25:11 christos Exp $ */
+/* $NetBSD: netbsd32_machdep.c,v 1.126 2019/08/21 12:33:12 maxv Exp $ */
/*
* Copyright (c) 2001 Wasabi Systems, Inc.
@@ -36,7 +36,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.125 2019/07/20 18:25:11 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_machdep.c,v 1.126 2019/08/21 12:33:12 maxv Exp $");
#ifdef _KERNEL_OPT
#include "opt_compat_netbsd.h"
@@ -903,12 +903,6 @@ startlwp32(void *arg)
userret(l);
}
-/*
- * For various reasons, the amd64 port can't do what the i386 port does,
- * and relies on catching invalid user contexts on exit from the kernel.
- * These functions perform the needed checks.
- */
-
int
check_sigcontext32(struct lwp *l, const struct netbsd32_sigcontext *scp)
{
@@ -923,21 +917,22 @@ check_sigcontext32(struct lwp *l, const
return EINVAL;
if (__predict_false(pmap->pm_ldt != NULL)) {
- /* Only when the LDT is user-set (with USER_LDT) */
+ /* Allow unfamiliar segment register values (USER_LDT). */
if (!USERMODE(scp->sc_cs))
return EINVAL;
} else {
if (!VALID_USER_CSEL32(scp->sc_cs))
return EINVAL;
if (scp->sc_fs != 0 && !VALID_USER_DSEL32(scp->sc_fs) &&
- !(VALID_USER_FSEL32(scp->sc_fs) && pcb->pcb_fs != 0))
+ !(VALID_USER_FSEL32(scp->sc_fs) && pcb->pcb_fs != 0))
return EINVAL;
if (scp->sc_gs != 0 && !VALID_USER_DSEL32(scp->sc_gs) &&
- !(VALID_USER_GSEL32(scp->sc_gs) && pcb->pcb_gs != 0))
+ !(VALID_USER_GSEL32(scp->sc_gs) && pcb->pcb_gs != 0))
return EINVAL;
if (scp->sc_es != 0 && !VALID_USER_DSEL32(scp->sc_es))
return EINVAL;
- if (!VALID_USER_DSEL32(scp->sc_ds) || !VALID_USER_DSEL32(scp->sc_ss))
+ if (!VALID_USER_DSEL32(scp->sc_ds) ||
+ !VALID_USER_DSEL32(scp->sc_ss))
return EINVAL;
}
@@ -950,36 +945,37 @@ check_sigcontext32(struct lwp *l, const
int
cpu_mcontext32_validate(struct lwp *l, const mcontext32_t *mcp)
{
+ struct pmap *pmap = l->l_proc->p_vmspace->vm_map.pmap;
const __greg32_t *gr;
struct trapframe *tf;
+ struct pcb *pcb;
gr = mcp->__gregs;
tf = l->l_md.md_regs;
+ pcb = lwp_getpcb(l);
if (((gr[_REG32_EFL] ^ tf->tf_rflags) & PSL_USERSTATIC) != 0)
return EINVAL;
-#ifdef USER_LDT
- /* Userland is allowed to have unfamiliar segment register values */
- if (!USERMODE(gr[_REG32_CS]))
- return EINVAL;
-#else
- struct pcb *pcb = lwp_getpcb(l);
-
- if (!VALID_USER_CSEL32(gr[_REG32_CS]))
- return EINVAL;
- if (gr[_REG32_FS] != 0 && !VALID_USER_DSEL32(gr[_REG32_FS]) &&
- !(VALID_USER_FSEL32(gr[_REG32_FS]) && pcb->pcb_fs != 0))
- return EINVAL;
- if (gr[_REG32_GS] != 0 && !VALID_USER_DSEL32(gr[_REG32_GS]) &&
- !(VALID_USER_GSEL32(gr[_REG32_GS]) && pcb->pcb_gs != 0))
- return EINVAL;
- if (gr[_REG32_ES] != 0 && !VALID_USER_DSEL32(gr[_REG32_ES]))
- return EINVAL;
- if (!VALID_USER_DSEL32(gr[_REG32_DS]) ||
- !VALID_USER_DSEL32(gr[_REG32_SS]))
- return EINVAL;
-#endif
+ if (__predict_false(pmap->pm_ldt != NULL)) {
+ /* Allow unfamiliar segment register values (USER_LDT). */
+ if (!USERMODE(gr[_REG32_CS]))
+ return EINVAL;
+ } else {
+ if (!VALID_USER_CSEL32(gr[_REG32_CS]))
+ return EINVAL;
+ if (gr[_REG32_FS] != 0 && !VALID_USER_DSEL32(gr[_REG32_FS]) &&
+ !(VALID_USER_FSEL32(gr[_REG32_FS]) && pcb->pcb_fs != 0))
+ return EINVAL;
+ if (gr[_REG32_GS] != 0 && !VALID_USER_DSEL32(gr[_REG32_GS]) &&
+ !(VALID_USER_GSEL32(gr[_REG32_GS]) && pcb->pcb_gs != 0))
+ return EINVAL;
+ if (gr[_REG32_ES] != 0 && !VALID_USER_DSEL32(gr[_REG32_ES]))
+ return EINVAL;
+ if (!VALID_USER_DSEL32(gr[_REG32_DS]) ||
+ !VALID_USER_DSEL32(gr[_REG32_SS]))
+ return EINVAL;
+ }
if (gr[_REG32_EIP] >= VM_MAXUSER_ADDRESS32)
return EINVAL;
