[PATCH v2 1/2] pci: imx6: avoid dereferencing program counter from user mode

[Stefan Agner]

The custom fault handler is currently only meant to handle kernel
mode bus faults. Exit in case the abort happened in user mode.

Signed-off-by: Stefan Agner <ste...@agner.ch>
---
 drivers/pci/controller/dwc/pci-imx6.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c 
b/drivers/pci/controller/dwc/pci-imx6.c
index 69f86234f7c0..54a29e441303 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -270,8 +270,14 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
                unsigned int fsr, struct pt_regs *regs)
 {
        unsigned long pc = instruction_pointer(regs);
-       unsigned long instr = *(unsigned long *)pc;
-       int reg = (instr >> 12) & 15;
+       unsigned long instr;
+       int reg;
+
+       if (user_mode(regs))
+               return 1;
+
+       instr = *(unsigned long *)pc;
+       reg = (instr >> 12) & 15;
 
        /*
         * If the instruction being executed was a read,
-- 
2.19.1