From: Dave Hansen <dave@sr71.net>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, x86@kernel.org,
torvalds@linux-foundation.org, Dave Hansen <dave@sr71.net>,
dave.hansen@linux.intel.com
Subject: [PATCH 13/33] x86, pkeys: pass VMA down in to fault signal generation code
Date: Fri, 12 Feb 2016 13:02:11 -0800 [thread overview]
Message-ID: <20160212210211.AD3B36A3@viggo.jf.intel.com> (raw)
In-Reply-To: <20160212210152.9CAD15B0@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
During a page fault, we look up the VMA to ensure that the fault
is in a region with a valid mapping. But, in the top-level page
fault code we don't need the VMA for much else. Once we have
decided that an access is bad, we are going to send a signal no
matter what and do not need the VMA any more. So we do not pass
it down in to the signal generation code.
But, for protection keys, we need the VMA. It tells us *which*
protection key we violated if we get a PF_PK. So, we need to
pass the VMA down and fill in siginfo->si_pkey.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
b/arch/x86/mm/fault.c | 50 ++++++++++++++++++++++++++++----------------------
1 file changed, 28 insertions(+), 22 deletions(-)
diff -puN arch/x86/mm/fault.c~pkeys-08-pass-down-vma arch/x86/mm/fault.c
--- a/arch/x86/mm/fault.c~pkeys-08-pass-down-vma 2016-02-12 10:44:19.441393337 -0800
+++ b/arch/x86/mm/fault.c 2016-02-12 10:44:19.445393520 -0800
@@ -171,7 +171,8 @@ is_prefetch(struct pt_regs *regs, unsign
static void
force_sig_info_fault(int si_signo, int si_code, unsigned long address,
- struct task_struct *tsk, int fault)
+ struct task_struct *tsk, struct vm_area_struct *vma,
+ int fault)
{
unsigned lsb = 0;
siginfo_t info;
@@ -656,6 +657,8 @@ no_context(struct pt_regs *regs, unsigne
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)) {
@@ -679,7 +682,8 @@ no_context(struct pt_regs *regs, unsigne
tsk->thread.cr2 = address;
/* XXX: hwpoison faults will set the wrong code. */
- force_sig_info_fault(signal, si_code, address, tsk, 0);
+ force_sig_info_fault(signal, si_code, address,
+ tsk, vma, 0);
}
/*
@@ -756,7 +760,8 @@ show_signal_msg(struct pt_regs *regs, un
static void
__bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, int si_code)
+ unsigned long address, struct vm_area_struct *vma,
+ int si_code)
{
struct task_struct *tsk = current;
@@ -799,7 +804,7 @@ __bad_area_nosemaphore(struct pt_regs *r
tsk->thread.error_code = error_code;
tsk->thread.trap_nr = X86_TRAP_PF;
- force_sig_info_fault(SIGSEGV, si_code, address, tsk, 0);
+ force_sig_info_fault(SIGSEGV, si_code, address, tsk, vma, 0);
return;
}
@@ -812,14 +817,14 @@ __bad_area_nosemaphore(struct pt_regs *r
static noinline void
bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
- unsigned long address)
+ unsigned long address, struct vm_area_struct *vma)
{
- __bad_area_nosemaphore(regs, error_code, address, SEGV_MAPERR);
+ __bad_area_nosemaphore(regs, error_code, address, vma, SEGV_MAPERR);
}
static void
__bad_area(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, int si_code)
+ unsigned long address, struct vm_area_struct *vma, int si_code)
{
struct mm_struct *mm = current->mm;
@@ -829,25 +834,25 @@ __bad_area(struct pt_regs *regs, unsigne
*/
up_read(&mm->mmap_sem);
- __bad_area_nosemaphore(regs, error_code, address, si_code);
+ __bad_area_nosemaphore(regs, error_code, address, vma, si_code);
}
static noinline void
bad_area(struct pt_regs *regs, unsigned long error_code, unsigned long address)
{
- __bad_area(regs, error_code, address, SEGV_MAPERR);
+ __bad_area(regs, error_code, address, NULL, SEGV_MAPERR);
}
static noinline void
bad_area_access_error(struct pt_regs *regs, unsigned long error_code,
- unsigned long address)
+ unsigned long address, struct vm_area_struct *vma)
{
- __bad_area(regs, error_code, address, SEGV_ACCERR);
+ __bad_area(regs, error_code, address, vma, SEGV_ACCERR);
}
static void
do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
- unsigned int fault)
+ struct vm_area_struct *vma, unsigned int fault)
{
struct task_struct *tsk = current;
int code = BUS_ADRERR;
@@ -874,12 +879,13 @@ do_sigbus(struct pt_regs *regs, unsigned
code = BUS_MCEERR_AR;
}
#endif
- force_sig_info_fault(SIGBUS, code, address, tsk, fault);
+ force_sig_info_fault(SIGBUS, code, address, tsk, vma, fault);
}
static noinline void
mm_fault_error(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, unsigned int fault)
+ unsigned long address, struct vm_area_struct *vma,
+ unsigned int fault)
{
if (fatal_signal_pending(current) && !(error_code & PF_USER)) {
no_context(regs, error_code, address, 0, 0);
@@ -903,9 +909,9 @@ mm_fault_error(struct pt_regs *regs, uns
} else {
if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|
VM_FAULT_HWPOISON_LARGE))
- do_sigbus(regs, error_code, address, fault);
+ do_sigbus(regs, error_code, address, vma, fault);
else if (fault & VM_FAULT_SIGSEGV)
- bad_area_nosemaphore(regs, error_code, address);
+ bad_area_nosemaphore(regs, error_code, address, vma);
else
BUG();
}
@@ -1119,7 +1125,7 @@ __do_page_fault(struct pt_regs *regs, un
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock:
*/
- bad_area_nosemaphore(regs, error_code, address);
+ bad_area_nosemaphore(regs, error_code, address, NULL);
return;
}
@@ -1132,7 +1138,7 @@ __do_page_fault(struct pt_regs *regs, un
pgtable_bad(regs, error_code, address);
if (unlikely(smap_violation(error_code, regs))) {
- bad_area_nosemaphore(regs, error_code, address);
+ bad_area_nosemaphore(regs, error_code, address, NULL);
return;
}
@@ -1141,7 +1147,7 @@ __do_page_fault(struct pt_regs *regs, un
* in a region with pagefaults disabled then we must not take the fault
*/
if (unlikely(faulthandler_disabled() || !mm)) {
- bad_area_nosemaphore(regs, error_code, address);
+ bad_area_nosemaphore(regs, error_code, address, NULL);
return;
}
@@ -1185,7 +1191,7 @@ __do_page_fault(struct pt_regs *regs, un
if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
if ((error_code & PF_USER) == 0 &&
!search_exception_tables(regs->ip)) {
- bad_area_nosemaphore(regs, error_code, address);
+ bad_area_nosemaphore(regs, error_code, address, NULL);
return;
}
retry:
@@ -1233,7 +1239,7 @@ retry:
*/
good_area:
if (unlikely(access_error(error_code, vma))) {
- bad_area_access_error(regs, error_code, address);
+ bad_area_access_error(regs, error_code, address, vma);
return;
}
@@ -1271,7 +1277,7 @@ good_area:
up_read(&mm->mmap_sem);
if (unlikely(fault & VM_FAULT_ERROR)) {
- mm_fault_error(regs, error_code, address, fault);
+ mm_fault_error(regs, error_code, address, vma, fault);
return;
}
_
--
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next prev parent reply other threads:[~2016-02-12 21:02 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-12 21:01 [PATCH 00/33] x86: Memory Protection Keys (v10) Dave Hansen
2016-02-12 21:01 ` [PATCH 01/33] mm: introduce get_user_pages_remote() Dave Hansen
2016-02-15 6:09 ` Balbir Singh
2016-02-15 16:29 ` Dave Hansen
2016-02-15 6:14 ` Srikar Dronamraju
2016-02-12 21:01 ` [PATCH 02/33] mm: overload get_user_pages() functions Dave Hansen
2016-02-16 8:36 ` Ingo Molnar
2016-02-17 18:15 ` Dave Hansen
2016-02-12 21:01 ` [PATCH 03/33] mm, gup: switch callers of get_user_pages() to not pass tsk/mm Dave Hansen
2016-02-12 21:01 ` [PATCH 04/33] x86, fpu: add placeholder for Processor Trace XSAVE state Dave Hansen
2016-02-12 21:02 ` [PATCH 05/33] x86, pkeys: Add Kconfig option Dave Hansen
2016-02-12 21:02 ` [PATCH 06/33] x86, pkeys: cpuid bit definition Dave Hansen
2016-02-12 21:02 ` [PATCH 07/33] x86, pkeys: define new CR4 bit Dave Hansen
2016-02-12 21:02 ` [PATCH 08/33] x86, pkeys: add PKRU xsave fields and data structure(s) Dave Hansen
2016-02-12 21:02 ` [PATCH 09/33] x86, pkeys: PTE bits for storing protection key Dave Hansen
2016-02-12 21:02 ` [PATCH 10/33] x86, pkeys: new page fault error code bit: PF_PK Dave Hansen
2016-02-12 21:02 ` [PATCH 11/33] x86, pkeys: store protection in high VMA flags Dave Hansen
2016-02-12 21:02 ` [PATCH 12/33] x86, pkeys: arch-specific protection bits Dave Hansen
2016-02-12 21:02 ` Dave Hansen [this message]
2016-02-12 21:02 ` [PATCH 14/33] signals, pkeys: notify userspace about protection key faults Dave Hansen
2016-02-12 21:02 ` [PATCH 15/33] x86, pkeys: fill in pkey field in siginfo Dave Hansen
2016-02-12 21:02 ` [PATCH 16/33] x86, pkeys: add functions to fetch PKRU Dave Hansen
2016-02-12 21:02 ` [PATCH 17/33] mm: factor out VMA fault permission checking Dave Hansen
2016-02-12 21:02 ` [PATCH 18/33] x86, mm: simplify get_user_pages() PTE bit handling Dave Hansen
2016-02-12 21:02 ` [PATCH 19/33] x86, pkeys: check VMAs and PTEs for protection keys Dave Hansen
2016-02-12 21:02 ` [PATCH 20/33] mm: do not enforce PKEY permissions on "foreign" mm access Dave Hansen
2016-02-12 21:02 ` [PATCH 21/33] x86, pkeys: optimize fault handling in access_error() Dave Hansen
2016-02-12 21:02 ` [PATCH 22/33] x86, pkeys: differentiate instruction fetches Dave Hansen
2016-02-12 21:02 ` [PATCH 23/33] x86, pkeys: dump PKRU with other kernel registers Dave Hansen
2016-02-12 21:02 ` [PATCH 24/33] x86, pkeys: dump pkey from VMA in /proc/pid/smaps Dave Hansen
2016-02-12 21:02 ` [PATCH 25/33] x86, pkeys: add Kconfig prompt to existing config option Dave Hansen
2016-02-12 21:02 ` [PATCH 26/33] x86, pkeys: actually enable Memory Protection Keys in CPU Dave Hansen
2016-02-12 21:02 ` [PATCH 27/33] mm, multi-arch: pass a protection key in to calc_vm_flag_bits() Dave Hansen
2016-02-12 21:02 ` [PATCH 28/33] x86, pkeys: add arch_validate_pkey() Dave Hansen
2016-02-12 21:02 ` [PATCH 29/33] x86: separate out LDT init from context init Dave Hansen
2016-02-12 21:02 ` [PATCH 30/33] x86, fpu: allow setting of XSAVE state Dave Hansen
2016-02-12 21:02 ` [PATCH 31/33] x86, pkeys: allow kernel to modify user pkey rights register Dave Hansen
2016-02-12 21:02 ` [PATCH 32/33] x86, pkeys: create an x86 arch_calc_vm_prot_bits() for VMA flags Dave Hansen
2016-02-12 21:02 ` [PATCH 33/33] x86, pkeys: execute-only support Dave Hansen
2016-02-17 21:27 ` Kees Cook
2016-02-17 21:33 ` Dave Hansen
2016-02-17 21:36 ` Kees Cook
2016-02-17 22:17 ` Andy Lutomirski
2016-02-17 22:53 ` Dave Hansen
2016-02-18 0:46 ` Andy Lutomirski
2016-02-16 9:29 ` [PATCH 00/33] x86: Memory Protection Keys (v10) Ingo Molnar
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