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Groups > linux.kernel > #1333126
| From | Dave Hansen <dave@sr71.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 13/33] x86, pkeys: pass VMA down in to fault signal generation code |
| Date | 2016-02-12 22:10 +0100 |
| Message-ID | <r1t8x-3TO-67@gated-at.bofh.it> (permalink) |
| References | <r1t8t-3TO-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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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[PATCH 00/33] x86: Memory Protection Keys (v10) Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[PATCH 18/33] x86, mm: simplify get_user_pages() PTE bit handling Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] x86/mm/gup: Simplify get_user_pages() PTE bit handling tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
[PATCH 23/33] x86, pkeys: dump PKRU with other kernel registers Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] x86/mm/pkeys: Dump PKRU with other kernel registers tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
[PATCH 30/33] x86, fpu: allow setting of XSAVE state Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] x86/fpu: Allow setting of XSAVE state tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
[PATCH 03/33] mm, gup: switch callers of get_user_pages() to not pass tsk/mm Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
[PATCH 19/33] x86, pkeys: check VMAs and PTEs for protection keys Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
[PATCH 26/33] x86, pkeys: actually enable Memory Protection Keys in CPU Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
[PATCH 07/33] x86, pkeys: define new CR4 bit Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] x86/cpu, x86/mm/pkeys: Define new CR4 bit tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
[PATCH 13/33] x86, pkeys: pass VMA down in to fault signal generation code Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
[tip:mm/pkeys] x86/mm/pkeys: Pass VMA down in to fault signal generation code tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
[PATCH 11/33] x86, pkeys: store protection in high VMA flags Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
[tip:mm/pkeys] mm/core, x86/mm/pkeys: Store protection bits in high VMA flags tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
[PATCH 10/33] x86, pkeys: new page fault error code bit: PF_PK Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
[tip:mm/pkeys] x86/mm/pkeys: Add new 'PF_PK' page fault error code bit tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
[PATCH 09/33] x86, pkeys: PTE bits for storing protection key Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
[tip:mm/pkeys] x86/mm/pkeys: Add PTE bits for storing protection key tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
[PATCH 06/33] x86, pkeys: cpuid bit definition Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
[tip:mm/pkeys] x86/cpufeature, x86/mm/pkeys: Add protection keys related CPUID definitions tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
[PATCH 02/33] mm: overload get_user_pages() functions Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
Re: [PATCH 02/33] mm: overload get_user_pages() functions Ingo Molnar <mingo@kernel.org> - 2016-02-16 09:40 +0100
Re: [PATCH 02/33] mm: overload get_user_pages() functions Dave Hansen <dave@sr71.net> - 2016-02-17 19:20 +0100
[tip:mm/pkeys] mm/gup: Overload get_user_pages() functions tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
[PATCH 01/33] mm: introduce get_user_pages_remote() Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
Re: [PATCH 01/33] mm: introduce get_user_pages_remote() Balbir Singh <bsingharora@gmail.com> - 2016-02-15 07:10 +0100
Re: [PATCH 01/33] mm: introduce get_user_pages_remote() Dave Hansen <dave@sr71.net> - 2016-02-15 17:30 +0100
Re: [PATCH 01/33] mm: introduce get_user_pages_remote() Srikar Dronamraju <srikar@linux.vnet.ibm.com> - 2016-02-15 07:20 +0100
[tip:x86/pkeys] mm/gup: Introduce get_user_pages_remote() tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-16 13:20 +0100
Re: [tip:x86/pkeys] mm/gup: Introduce get_user_pages_remote() Konstantin Khlebnikov <koct9i@gmail.com> - 2016-02-20 07:30 +0100
[PATCH 05/33] x86, pkeys: Add Kconfig option Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
[tip:mm/pkeys] x86/mm/pkeys: Add Kconfig option tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
[PATCH] x86/mm/pkeys: Do not enable them by default Borislav Petkov <bp@alien8.de> - 2016-02-19 12:30 +0100
Re: [PATCH] x86/mm/pkeys: Do not enable them by default Dave Hansen <dave@sr71.net> - 2016-02-19 18:20 +0100
Re: [PATCH] x86/mm/pkeys: Do not enable them by default Borislav Petkov <bp@alien8.de> - 2016-02-19 18:30 +0100
Re: [PATCH] x86/mm/pkeys: Do not enable them by default Dave Hansen <dave@sr71.net> - 2016-02-19 18:50 +0100
Re: [PATCH] x86/mm/pkeys: Do not enable them by default Borislav Petkov <bp@alien8.de> - 2016-02-19 19:40 +0100
Re: [PATCH 00/33] x86: Memory Protection Keys (v10) Ingo Molnar <mingo@kernel.org> - 2016-02-16 10:30 +0100
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