From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Catalin Marinas , Tim Northover Subject: [ 29/73] arm64: Ignore the write ESR flag on cache maintenance faults Date: Thu, 9 May 2013 15:31:52 -0700 Message-Id: <20130509222801.151723687@linuxfoundation.org> In-Reply-To: <20130509222757.917088509@linuxfoundation.org> References: <20130509222757.917088509@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Catalin Marinas commit 0e7f7bcc3fc87489cda5aa6aff8ce40eed912279 upstream. ESR.WnR bit is always set on data cache maintenance faults even though the page is not required to have write permission. If a translation fault (page not yet mapped) happens for read-only user address range, Linux incorrectly assumes a permission fault. This patch adds the check of the ESR.CM bit during the page fault handling to ignore the 'write' flag. Signed-off-by: Catalin Marinas Reported-by: Tim Northover Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/fault.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -148,6 +148,7 @@ void do_bad_area(unsigned long addr, uns #define VM_FAULT_BADACCESS 0x020000 #define ESR_WRITE (1 << 6) +#define ESR_CM (1 << 8) #define ESR_LNX_EXEC (1 << 24) /* @@ -206,7 +207,7 @@ static int __kprobes do_page_fault(unsig struct task_struct *tsk; struct mm_struct *mm; int fault, sig, code; - int write = esr & ESR_WRITE; + bool write = (esr & ESR_WRITE) && !(esr & ESR_CM); unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | (write ? FAULT_FLAG_WRITE : 0);