3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Russell King <rmk+ker...@arm.linux.org.uk>

commit b255188f90e2bade1bd11a986dd1ca4861869f4d upstream.

Paolo Pisati reports that IPv6 triggers this warning:

BUG: scheduling while atomic: swapper/0/0/0x40000100
Modules linked in:
[<c001b1c4>] (unwind_backtrace+0x0/0xf0) from [<c0503c5c>] 
(__schedule_bug+0x48/0x5c)
[<c0503c5c>] (__schedule_bug+0x48/0x5c) from [<c0508608>] 
(__schedule+0x700/0x740)
[<c0508608>] (__schedule+0x700/0x740) from [<c007007c>] 
(__cond_resched+0x24/0x34)
[<c007007c>] (__cond_resched+0x24/0x34) from [<c05086dc>] 
(_cond_resched+0x3c/0x44)
[<c05086dc>] (_cond_resched+0x3c/0x44) from [<c0021f6c>] 
(do_alignment+0x178/0x78c)
[<c0021f6c>] (do_alignment+0x178/0x78c) from [<c00083e0>] 
(do_DataAbort+0x34/0x98)
[<c00083e0>] (do_DataAbort+0x34/0x98) from [<c0509a60>] (__dabt_svc+0x40/0x60)
Exception stack(0xc0763d70 to 0xc0763db8)
3d60:                                     e97e805e e97e806e 2c000000 11000000
3d80: ea86bb00 0000002c 00000011 e97e807e c076d2a8 e97e805e e97e806e 0000002c
3da0: 3d000000 c0763dbc c04b98fc c02a8490 00000113 ffffffff
[<c0509a60>] (__dabt_svc+0x40/0x60) from [<c02a8490>] 
(__csum_ipv6_magic+0x8/0xc8)

Fix this by using probe_kernel_address() stead of __get_user().

Reported-by: Paolo Pisati <p.pis...@gmail.com>
Tested-by: Paolo Pisati <p.pis...@gmail.com>
Signed-off-by: Russell King <rmk+ker...@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/arm/mm/alignment.c |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -721,7 +721,6 @@ do_alignment(unsigned long addr, unsigne
        unsigned long instr = 0, instrptr;
        int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs 
*regs);
        unsigned int type;
-       mm_segment_t fs;
        unsigned int fault;
        u16 tinstr = 0;
        int isize = 4;
@@ -729,16 +728,15 @@ do_alignment(unsigned long addr, unsigne
 
        instrptr = instruction_pointer(regs);
 
-       fs = get_fs();
-       set_fs(KERNEL_DS);
        if (thumb_mode(regs)) {
-               fault = __get_user(tinstr, (u16 *)(instrptr & ~1));
+               u16 *ptr = (u16 *)(instrptr & ~1);
+               fault = probe_kernel_address(ptr, tinstr);
                if (!fault) {
                        if (cpu_architecture() >= CPU_ARCH_ARMv7 &&
                            IS_T32(tinstr)) {
                                /* Thumb-2 32-bit */
                                u16 tinst2 = 0;
-                               fault = __get_user(tinst2, (u16 *)(instrptr+2));
+                               fault = probe_kernel_address(ptr + 1, tinst2);
                                instr = (tinstr << 16) | tinst2;
                                thumb2_32b = 1;
                        } else {
@@ -747,8 +745,7 @@ do_alignment(unsigned long addr, unsigne
                        }
                }
        } else
-               fault = __get_user(instr, (u32 *)instrptr);
-       set_fs(fs);
+               fault = probe_kernel_address(instrptr, instr);
 
        if (fault) {
                type = TYPE_FAULT;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to