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authorAndy Lutomirski <luto@kernel.org>2020-07-17 16:53:55 -0700
committerThomas Gleixner <tglx@linutronix.de>2020-07-18 12:31:49 +0200
commitcadfad870154e14f745ec845708bc17d166065f2 (patch)
tree879e0402ec50885291708e574e56830130f424fb /arch/x86/kernel/process.c
parent81e96851ea32deb2c921c870eecabf335f598aeb (diff)
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x86/ioperm: Fix io bitmap invalidation on Xen PV
tss_invalidate_io_bitmap() wasn't wired up properly through the pvop machinery, so the TSS and Xen's io bitmap would get out of sync whenever disabling a valid io bitmap. Add a new pvop for tss_invalidate_io_bitmap() to fix it. This is XSA-329. Fixes: 22fe5b0439dd ("x86/ioperm: Move TSS bitmap update to exit to user work") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/d53075590e1f91c19f8af705059d3ff99424c020.1595030016.git.luto@kernel.org
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r--arch/x86/kernel/process.c18
1 files changed, 2 insertions, 16 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index f362ce0d5ac0..fe67dbd76e51 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -322,20 +322,6 @@ void arch_setup_new_exec(void)
}
#ifdef CONFIG_X86_IOPL_IOPERM
-static inline void tss_invalidate_io_bitmap(struct tss_struct *tss)
-{
- /*
- * Invalidate the I/O bitmap by moving io_bitmap_base outside the
- * TSS limit so any subsequent I/O access from user space will
- * trigger a #GP.
- *
- * This is correct even when VMEXIT rewrites the TSS limit
- * to 0x67 as the only requirement is that the base points
- * outside the limit.
- */
- tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_INVALID;
-}
-
static inline void switch_to_bitmap(unsigned long tifp)
{
/*
@@ -346,7 +332,7 @@ static inline void switch_to_bitmap(unsigned long tifp)
* user mode.
*/
if (tifp & _TIF_IO_BITMAP)
- tss_invalidate_io_bitmap(this_cpu_ptr(&cpu_tss_rw));
+ tss_invalidate_io_bitmap();
}
static void tss_copy_io_bitmap(struct tss_struct *tss, struct io_bitmap *iobm)
@@ -380,7 +366,7 @@ void native_tss_update_io_bitmap(void)
u16 *base = &tss->x86_tss.io_bitmap_base;
if (!test_thread_flag(TIF_IO_BITMAP)) {
- tss_invalidate_io_bitmap(tss);
+ native_tss_invalidate_io_bitmap();
return;
}