aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/mm/fault.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-10-01 13:55:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-10-01 13:55:32 -0700
commit368f89984bb971b9f8b69eeb85ab19a89f985809 (patch)
tree4a5b4f07fed0043114ca40a64f06e9b0cdab397d /arch/x86/mm/fault.c
parentc42ed9f91fa1868db0e7748ec6d816a484b11890 (diff)
parent196bd485ee4f03ce4c690bfcf38138abfcd0a4bc (diff)
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner: "This contains the following fixes and improvements: - Avoid dereferencing an unprotected VMA pointer in the fault signal generation code - Fix inline asm call constraints for GCC 4.4 - Use existing register variable to retrieve the stack pointer instead of forcing the compiler to create another indirect access which results in excessive extra 'mov %rsp, %<dst>' instructions - Disable branch profiling for the memory encryption code to prevent an early boot crash - Fix a sparse warning caused by casting the __user annotation in __get_user_asm_u64() away - Fix an off by one error in the loop termination of the error patch in the x86 sysfs init code - Add missing CPU IDs to various Intel specific drivers to enable the functionality on recent hardware - More (init) constification in the numachip code" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Use register variable to get stack pointer value x86/mm: Disable branch profiling in mem_encrypt.c x86/asm: Fix inline asm call constraints for GCC 4.4 perf/x86/intel/uncore: Correct num_boxes for IIO and IRP perf/x86/intel/rapl: Add missing CPU IDs perf/x86/msr: Add missing CPU IDs perf/x86/intel/cstate: Add missing CPU IDs x86: Don't cast away the __user in __get_user_asm_u64() x86/sysfs: Fix off-by-one error in loop termination x86/mm: Fix fault error path using unsafe vma pointer x86/numachip: Add const and __initconst to numachip2_clockevent
Diffstat (limited to 'arch/x86/mm/fault.c')
-rw-r--r--arch/x86/mm/fault.c47
1 files changed, 24 insertions, 23 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 39567b5c33da..e2baeaa053a5 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -192,8 +192,7 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
* 6. T1 : reaches here, sees vma_pkey(vma)=5, when we really
* faulted on a pte with its pkey=4.
*/
-static void fill_sig_info_pkey(int si_code, siginfo_t *info,
- struct vm_area_struct *vma)
+static void fill_sig_info_pkey(int si_code, siginfo_t *info, u32 *pkey)
{
/* This is effectively an #ifdef */
if (!boot_cpu_has(X86_FEATURE_OSPKE))
@@ -209,7 +208,7 @@ static void fill_sig_info_pkey(int si_code, siginfo_t *info,
* valid VMA, so we should never reach this without a
* valid VMA.
*/
- if (!vma) {
+ if (!pkey) {
WARN_ONCE(1, "PKU fault with no VMA passed in");
info->si_pkey = 0;
return;
@@ -219,13 +218,12 @@ static void fill_sig_info_pkey(int si_code, siginfo_t *info,
* absolutely guranteed to be 100% accurate because of
* the race explained above.
*/
- info->si_pkey = vma_pkey(vma);
+ info->si_pkey = *pkey;
}
static void
force_sig_info_fault(int si_signo, int si_code, unsigned long address,
- struct task_struct *tsk, struct vm_area_struct *vma,
- int fault)
+ struct task_struct *tsk, u32 *pkey, int fault)
{
unsigned lsb = 0;
siginfo_t info;
@@ -240,7 +238,7 @@ force_sig_info_fault(int si_signo, int si_code, unsigned long address,
lsb = PAGE_SHIFT;
info.si_addr_lsb = lsb;
- fill_sig_info_pkey(si_code, &info, vma);
+ fill_sig_info_pkey(si_code, &info, pkey);
force_sig_info(si_signo, &info, tsk);
}
@@ -762,8 +760,6 @@ no_context(struct pt_regs *regs, unsigned long error_code,
struct task_struct *tsk = current;
unsigned long flags;
int sig;
- /* No context means no VMA to pass down */
- struct vm_area_struct *vma = NULL;
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs, X86_TRAP_PF)) {
@@ -788,7 +784,7 @@ no_context(struct pt_regs *regs, unsigned long error_code,
/* XXX: hwpoison faults will set the wrong code. */
force_sig_info_fault(signal, si_code, address,
- tsk, vma, 0);
+ tsk, NULL, 0);
}
/*
@@ -896,8 +892,7 @@ show_signal_msg(struct pt_regs *regs, unsigned long error_code,
static void
__bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, struct vm_area_struct *vma,
- int si_code)
+ unsigned long address, u32 *pkey, int si_code)
{
struct task_struct *tsk = current;
@@ -945,7 +940,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
tsk->thread.error_code = error_code;
tsk->thread.trap_nr = X86_TRAP_PF;
- force_sig_info_fault(SIGSEGV, si_code, address, tsk, vma, 0);
+ force_sig_info_fault(SIGSEGV, si_code, address, tsk, pkey, 0);
return;
}
@@ -958,9 +953,9 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
static noinline void
bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, struct vm_area_struct *vma)
+ unsigned long address, u32 *pkey)
{
- __bad_area_nosemaphore(regs, error_code, address, vma, SEGV_MAPERR);
+ __bad_area_nosemaphore(regs, error_code, address, pkey, SEGV_MAPERR);
}
static void
@@ -968,6 +963,10 @@ __bad_area(struct pt_regs *regs, unsigned long error_code,
unsigned long address, struct vm_area_struct *vma, int si_code)
{
struct mm_struct *mm = current->mm;
+ u32 pkey;
+
+ if (vma)
+ pkey = vma_pkey(vma);
/*
* Something tried to access memory that isn't in our memory map..
@@ -975,7 +974,8 @@ __bad_area(struct pt_regs *regs, unsigned long error_code,
*/
up_read(&mm->mmap_sem);
- __bad_area_nosemaphore(regs, error_code, address, vma, si_code);
+ __bad_area_nosemaphore(regs, error_code, address,
+ (vma) ? &pkey : NULL, si_code);
}
static noinline void
@@ -1018,7 +1018,7 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code,
static void
do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
- struct vm_area_struct *vma, unsigned int fault)
+ u32 *pkey, unsigned int fault)
{
struct task_struct *tsk = current;
int code = BUS_ADRERR;
@@ -1045,13 +1045,12 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
code = BUS_MCEERR_AR;
}
#endif
- force_sig_info_fault(SIGBUS, code, address, tsk, vma, fault);
+ force_sig_info_fault(SIGBUS, code, address, tsk, pkey, fault);
}
static noinline void
mm_fault_error(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, struct vm_area_struct *vma,
- unsigned int fault)
+ unsigned long address, u32 *pkey, unsigned int fault)
{
if (fatal_signal_pending(current) && !(error_code & PF_USER)) {
no_context(regs, error_code, address, 0, 0);
@@ -1075,9 +1074,9 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
} else {
if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|
VM_FAULT_HWPOISON_LARGE))
- do_sigbus(regs, error_code, address, vma, fault);
+ do_sigbus(regs, error_code, address, pkey, fault);
else if (fault & VM_FAULT_SIGSEGV)
- bad_area_nosemaphore(regs, error_code, address, vma);
+ bad_area_nosemaphore(regs, error_code, address, pkey);
else
BUG();
}
@@ -1267,6 +1266,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
struct mm_struct *mm;
int fault, major = 0;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+ u32 pkey;
tsk = current;
mm = tsk->mm;
@@ -1467,9 +1467,10 @@ good_area:
return;
}
+ pkey = vma_pkey(vma);
up_read(&mm->mmap_sem);
if (unlikely(fault & VM_FAULT_ERROR)) {
- mm_fault_error(regs, error_code, address, vma, fault);
+ mm_fault_error(regs, error_code, address, &pkey, fault);
return;
}

Privacy Policy