aboutsummaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorKumar Gala <galak@kernel.crashing.org>2010-11-17 07:20:32 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2010-11-18 14:54:23 +1100
commit82ae5eaffad40a6d4738e8a57e48dd0d903a9ef0 (patch)
treecae9e5c8adf721459beaad25d54cf7a2b6c30b14 /arch
parent1c2c25c78740b2796c7c06640784cb6732fa4907 (diff)
downloadlinaro-lsk-82ae5eaffad40a6d4738e8a57e48dd0d903a9ef0.tar.gz
powerpc/mm: Fix module instruction tlb fault handling on Book-E 64
We were seeing oops like the following when we did an rmmod on a module: Unable to handle kernel paging request for instruction fetch Faulting instruction address: 0x8000000000008010 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2 P5020 DS last sysfs file: /sys/devices/qman-portals.2/qman-pool.9/uevent Modules linked in: qman_tester(-) NIP: 8000000000008010 LR: c000000000074858 CTR: 8000000000008010 REGS: c00000002e29bab0 TRAP: 0400 Not tainted (2.6.34.6-00744-g2d21f14) MSR: 0000000080029000 <EE,ME,CE> CR: 24000448 XER: 00000000 TASK = c00000007a8be600[4987] 'rmmod' THREAD: c00000002e298000 CPU: 1 GPR00: 8000000000008010 c00000002e29bd30 8000000000012798 c00000000035fb28 GPR04: 0000000000000002 0000000000000002 0000000024022428 c000000000009108 GPR08: fffffffffffffffe 800000000000a618 c0000000003c13c8 0000000000000000 GPR12: 0000000022000444 c00000000fffed00 0000000000000000 0000000000000000 GPR16: 00000000100c0000 0000000000000000 00000000100dabc8 0000000010099688 GPR20: 0000000000000000 00000000100cfc28 0000000000000000 0000000010011a44 GPR24: 00000000100017b2 0000000000000000 0000000000000000 0000000000000880 GPR28: c00000000035fb28 800000000000a7b8 c000000000376d80 c0000000003cce50 NIP [8000000000008010] .test_exit+0x0/0x10 [qman_tester] LR [c000000000074858] .SyS_delete_module+0x1f8/0x2f0 Call Trace: [c00000002e29bd30] [c0000000000748b4] .SyS_delete_module+0x254/0x2f0 (unreliable) [c00000002e29be30] [c000000000000580] syscall_exit+0x0/0x2c Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX 38600000 4e800020 60000000 60000000 <4e800020> 60000000 60000000 60000000 ---[ end trace 4f57124939a84dc8 ]--- This appears to be due to checking the wrong permission bits in the instruction_tlb_miss handling if the address that faulted was in vmalloc space. We need to look at the supervisor execute (_PAGE_BAP_SX) bit and not the user bit (_PAGE_BAP_UX/_PAGE_EXEC). Also removed a branch level since it did not appear to be used. Reported-by: Jeffrey Ladouceur <Jeffrey.Ladouceur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/mm/tlb_low_64e.S5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S
index 8b04c54e596..8526bd9d2aa 100644
--- a/arch/powerpc/mm/tlb_low_64e.S
+++ b/arch/powerpc/mm/tlb_low_64e.S
@@ -138,8 +138,11 @@
cmpldi cr0,r15,0 /* Check for user region */
std r14,EX_TLB_ESR(r12) /* write crazy -1 to frame */
beq normal_tlb_miss
+
+ li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */
+ oris r11,r11,_PAGE_ACCESSED@h
/* XXX replace the RMW cycles with immediate loads + writes */
-1: mfspr r10,SPRN_MAS1
+ mfspr r10,SPRN_MAS1
cmpldi cr0,r15,8 /* Check for vmalloc region */
rlwinm r10,r10,0,16,1 /* Clear TID */
mtspr SPRN_MAS1,r10