From dff2aa7af8c96a11f75d858859f0e0c78b193d12 Mon Sep 17 00:00:00 2001 From: Kautuk Consul Date: Mon, 2 Apr 2012 18:19:49 +0100 Subject: ARM: 7368/1: fault.c: correct how the tsk->[maj|min]_flt gets incremented commit 8878a539ff19a43cf3729e7562cd528f490246ae was done by me to make the page fault handler retryable as well as interruptible. Due to this commit, there is a mistake in the way in which tsk->[maj|min]_flt counter gets incremented for VM_FAULT_ERROR: If VM_FAULT_ERROR is returned in the fault flags by handle_mm_fault, then either maj_flt or min_flt will get incremented. This is wrong as in the case of a VM_FAULT_ERROR we need to be skip ahead to the error handling code in do_page_fault. Added a check after the call to __do_page_fault() to check for (fault & VM_FAULT_ERROR). Signed-off-by: Kautuk Consul Signed-off-by: Russell King --- arch/arm/mm/fault.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mm/fault.c') diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 9055b5a84ec5..f07467533365 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -320,7 +320,7 @@ retry: */ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); - if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) { if (fault & VM_FAULT_MAJOR) { tsk->maj_flt++; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, -- cgit v1.2.3 From 9b61a4d1b2064dbd0c9e61754305ac852170509f Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 16 May 2012 15:19:20 +0100 Subject: ARM: prevent VM_GROWSDOWN mmaps extending below FIRST_USER_ADDRESS Cc: Reported-by: Al Viro Signed-off-by: Russell King --- arch/arm/mm/fault.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm/mm/fault.c') diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index f07467533365..5bb48356d217 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -247,7 +247,9 @@ good_area: return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags); check_stack: - if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) + /* Don't allow expansion below FIRST_USER_ADDRESS */ + if (vma->vm_flags & VM_GROWSDOWN && + addr >= FIRST_USER_ADDRESS && !expand_stack(vma, addr)) goto good_area; out: return fault; -- cgit v1.2.3