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authorLinus Torvalds2016-05-25 17:37:33 -0700
committerLinus Torvalds2016-05-25 17:37:33 -0700
commit2f7c3a18a2dc79ddf7b83ae199b099a675e1adb2 (patch)
treec43795eb48dc102b25ef2bfd78dfc075ff93feaa /arch/x86/mm
parentf89eae4ee7e075e576bd4b4d2db901023421a3be (diff)
parentdc4fac84f8e66b147921ebdc385e767d5def7422 (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: "Misc fixes: EFI, entry code, pkeys and MPX fixes, TASK_SIZE cleanups and a tsc frequency table fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Switch from TASK_SIZE to TASK_SIZE_MAX in the page fault code x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits x86/mm/mpx: Work around MPX erratum SKD046 x86/entry/64: Fix stack return address retrieval in thunk x86/efi: Fix 7-parameter efi_call()s x86/cpufeature, x86/mm/pkeys: Fix broken compile-time disabling of pkeys x86/tsc: Add missing Cherrytrail frequency to the table
Diffstat (limited to 'arch/x86/mm')
-rw-r--r--arch/x86/mm/fault.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 5ce1ed02f7e8..7d1fa7cd2374 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -292,7 +292,7 @@ void vmalloc_sync_all(void)
return;
for (address = VMALLOC_START & PMD_MASK;
- address >= TASK_SIZE && address < FIXADDR_TOP;
+ address >= TASK_SIZE_MAX && address < FIXADDR_TOP;
address += PMD_SIZE) {
struct page *page;
@@ -854,8 +854,13 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
return;
}
#endif
- /* Kernel addresses are always protection faults: */
- if (address >= TASK_SIZE)
+
+ /*
+ * To avoid leaking information about the kernel page table
+ * layout, pretend that user-mode accesses to kernel addresses
+ * are always protection faults.
+ */
+ if (address >= TASK_SIZE_MAX)
error_code |= PF_PROT;
if (likely(show_unhandled_signals))