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authorLinus Torvalds <torvalds@linux-foundation.org>2019-12-01 19:05:07 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-01 19:05:07 -0800
commite5b3fc125d768eacd73bb4dc5019f0ce95635af4 (patch)
tree4f7e06f8a0493865a6b604bbcef5118c4582ebcf /arch/x86/kernel/process.c
parentb7fcf31f7036895ca8fc3a30eefffab0e82f75f6 (diff)
parent91298f1a302dad0f0f630413c812818636faa8a0 (diff)
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar: "Various fixes: - Fix the PAT performance regression that downgraded write-combining device memory regions to uncached. - There's been a number of bugs in 32-bit double fault handling - hopefully all fixed now. - Fix an LDT crash - Fix an FPU over-optimization that broke with GCC9 code optimizations. - Misc cleanups" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/pat: Fix off-by-one bugs in interval tree search x86/ioperm: Save an indentation level in tss_update_io_bitmap() x86/fpu: Don't cache access to fpu_fpregs_owner_ctx x86/entry/32: Remove unused 'restore_all_notrace' local label x86/ptrace: Document FSBASE and GSBASE ABI oddities x86/ptrace: Remove set_segment_reg() implementations for current x86/traps: die() instead of panicking on a double fault x86/doublefault/32: Rewrite the x86_32 #DF handler and unify with 64-bit x86/doublefault/32: Move #DF stack and TSS to cpu_entry_area x86/doublefault/32: Rename doublefault.c to doublefault_32.c x86/traps: Disentangle the 32-bit and 64-bit doublefault code lkdtm: Add a DOUBLE_FAULT crash type on x86 selftests/x86/single_step_syscall: Check SYSENTER directly x86/mm/32: Sync only to VMALLOC_END in vmalloc_sync_all()
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r--arch/x86/kernel/process.c52
1 files changed, 26 insertions, 26 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index bd2a11ca5dd6..61e93a318983 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -377,37 +377,37 @@ static void tss_copy_io_bitmap(struct tss_struct *tss, struct io_bitmap *iobm)
void tss_update_io_bitmap(void)
{
struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
+ struct thread_struct *t = &current->thread;
u16 *base = &tss->x86_tss.io_bitmap_base;
- if (test_thread_flag(TIF_IO_BITMAP)) {
- struct thread_struct *t = &current->thread;
-
- if (IS_ENABLED(CONFIG_X86_IOPL_IOPERM) && t->iopl_emul == 3) {
- *base = IO_BITMAP_OFFSET_VALID_ALL;
- } else {
- struct io_bitmap *iobm = t->io_bitmap;
- /*
- * Only copy bitmap data when the sequence number
- * differs. The update time is accounted to the
- * incoming task.
- */
- if (tss->io_bitmap.prev_sequence != iobm->sequence)
- tss_copy_io_bitmap(tss, iobm);
-
- /* Enable the bitmap */
- *base = IO_BITMAP_OFFSET_VALID_MAP;
- }
+ if (!test_thread_flag(TIF_IO_BITMAP)) {
+ tss_invalidate_io_bitmap(tss);
+ return;
+ }
+
+ if (IS_ENABLED(CONFIG_X86_IOPL_IOPERM) && t->iopl_emul == 3) {
+ *base = IO_BITMAP_OFFSET_VALID_ALL;
+ } else {
+ struct io_bitmap *iobm = t->io_bitmap;
+
/*
- * Make sure that the TSS limit is covering the io bitmap.
- * It might have been cut down by a VMEXIT to 0x67 which
- * would cause a subsequent I/O access from user space to
- * trigger a #GP because tbe bitmap is outside the TSS
- * limit.
+ * Only copy bitmap data when the sequence number differs. The
+ * update time is accounted to the incoming task.
*/
- refresh_tss_limit();
- } else {
- tss_invalidate_io_bitmap(tss);
+ if (tss->io_bitmap.prev_sequence != iobm->sequence)
+ tss_copy_io_bitmap(tss, iobm);
+
+ /* Enable the bitmap */
+ *base = IO_BITMAP_OFFSET_VALID_MAP;
}
+
+ /*
+ * Make sure that the TSS limit is covering the IO bitmap. It might have
+ * been cut down by a VMEXIT to 0x67 which would cause a subsequent I/O
+ * access from user space to trigger a #GP because tbe bitmap is outside
+ * the TSS limit.
+ */
+ refresh_tss_limit();
}
#else /* CONFIG_X86_IOPL_IOPERM */
static inline void switch_to_bitmap(unsigned long tifp) { }