From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@lists.ozlabs.org
Cc: aneesh.kumar@linux.vnet.ibm.com,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [PATCH 18/24] powerpc/mm: Move/simplify faulthandler_disabled() and !mm check
Date: Wed, 19 Jul 2017 14:49:40 +1000 [thread overview]
Message-ID: <20170719044946.22030-18-benh@kernel.crashing.org> (raw)
In-Reply-To: <20170719044946.22030-1-benh@kernel.crashing.org>
Do the check before we re-enable interrupts and clean the code
up a bit.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/mm/fault.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 6f3a2437008a..c5859ffd3a96 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -355,24 +355,23 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
if (unlikely(!is_user && bad_kernel_fault(is_exec, error_code, address)))
return SIGSEGV;
+ /*
+ * If we're in an interrupt, have no user context or are running
+ * in a region with pagefaults disabled then we must not take the fault
+ */
+ if (unlikely(faulthandler_disabled() || !mm)) {
+ if (is_user)
+ printk_ratelimited(KERN_ERR "Page fault in user mode"
+ " with faulthandler_disabled()=%d"
+ " mm=%=p\n",
+ faulthandler_disabled(), mm);
+ return bad_area_nosemaphore(regs, address);
+ }
+
/* We restore the interrupt state now */
if (!arch_irq_disabled_regs(regs))
local_irq_enable();
- if (faulthandler_disabled() || mm == NULL) {
- if (!is_user)
- return SIGSEGV;
-
- /* faulthandler_disabled() in user mode is really bad,
- as is current->mm == NULL. */
- printk(KERN_EMERG "Page fault in user mode with "
- "faulthandler_disabled() = %d mm = %p\n",
- faulthandler_disabled(), mm);
- printk(KERN_EMERG "NIP = %lx MSR = %lx\n",
- regs->nip, regs->msr);
- die("Weird page fault", regs, SIGSEGV);
- }
-
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
/*
--
2.13.3
next prev parent reply other threads:[~2017-07-19 4:57 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-19 4:49 [PATCH 01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 02/24] powerpc/mm: Pre-filter SRR1 bits before do_page_fault() Benjamin Herrenschmidt
2017-07-22 16:43 ` LEROY Christophe
2017-07-23 1:10 ` Benjamin Herrenschmidt
2017-07-24 13:48 ` Michael Ellerman
2017-07-19 4:49 ` [PATCH 03/24] powerpc/6xx: Handle DABR match before calling do_page_fault Benjamin Herrenschmidt
2017-08-03 0:19 ` Michael Ellerman
2017-08-03 1:00 ` Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 04/24] powerpc/mm: Update definitions of DSISR bits Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 05/24] powerpc/mm: Update bits used to skip hash_page Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 06/24] powerpc/mm: Use symbolic constants for filtering SRR1 bits on ISIs Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 07/24] powerpc/mm: Move out definition of CPU specific is_write bits Benjamin Herrenschmidt
2017-07-22 16:40 ` LEROY Christophe
2017-07-23 1:06 ` Benjamin Herrenschmidt
2017-07-24 11:58 ` Michael Ellerman
2017-07-19 4:49 ` [PATCH 08/24] powerpc/mm: Move error_code checks for bad faults earlier Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 09/24] powerpc/mm: Overhaul handling of bad page faults Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 10/24] powerpc/mm: Move debugger check to notify_page_fault() Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 11/24] powerpc/mm: Simplify returns from __do_page_fault Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 12/24] powerpc/mm: Fix reporting of kernel execute faults Benjamin Herrenschmidt
2018-11-07 8:35 ` Christophe LEROY
2018-11-07 10:39 ` Benjamin Herrenschmidt
[not found] ` <87zhtr5d1v.fsf@linux.ibm.com>
2018-11-30 6:08 ` Christophe LEROY
2017-07-19 4:49 ` [PATCH 13/24] powerpc/mm: Make bad_area* helper functions Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 14/24] powerpc/mm: Rework mm_fault_error() Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 15/24] powerpc/mm: Move CMO accounting out of do_page_fault into a helper Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 16/24] powerpc/mm: Cosmetic fix to page fault accounting Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 17/24] powerpc/mm: Move the DSISR_PROTFAULT sanity check Benjamin Herrenschmidt
2017-07-19 4:49 ` Benjamin Herrenschmidt [this message]
2017-07-19 4:49 ` [PATCH 19/24] powerpc/mm: Add a bunch of (un)likely annotations to do_page_fault Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 20/24] powerpc/mm: Set fault flags earlier Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 21/24] powerpc/mm: Move page fault VMA access checks to a helper Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 22/24] powerpc/mm: Don't lose "major" fault indication on retry Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 23/24] powerpc/mm: Cleanup check for stack expansion Benjamin Herrenschmidt
2017-07-21 16:59 ` LEROY Christophe
2017-07-24 10:47 ` Michael Ellerman
2017-07-24 17:34 ` LEROY Christophe
2017-07-25 11:19 ` Michael Ellerman
2017-07-31 11:37 ` Christophe LEROY
2017-07-19 4:49 ` [PATCH 24/24] powerpc: Remove old unused icswx based coprocessor support Benjamin Herrenschmidt
2017-08-07 10:41 ` [01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Michael Ellerman
2017-08-07 16:37 ` Christophe LEROY
2017-08-08 2:16 ` Michael Ellerman
2017-08-08 6:45 ` Christophe LEROY
2017-08-08 10:00 ` Michael Ellerman
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