On Wed, 1 Feb 2012 18:42:52 +0000 Dave Airlie airlied@gmail.com wrote:

On Tue, Jan 24, 2012 at 2:10 PM, Alex Deucher alexdeucher@gmail.com wrote:

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On Sun, Jan 22, 2012 at 9:43 AM, Igor Murzov intergalactic.anonymous@gmail.com wrote:

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From 77c912ea1eca50a93a34d5be69f9dc96a8bef0d8 Mon Sep 17 00:00:00 2001 From: Igor Murzov e-mail@date.by Date: Sun, 22 Jan 2012 19:02:27 +0400 Subject: [PATCH 1/2] drm/radeon: fix invalid memory access in radeon_atrm_get_bios()

At a boot time I observed following bug:

BUG: unable to handle kernel paging request at ffff8800a4244000  IP: [<ffffffff81275b5b>] memcpy+0xb/0x120  PGD 1816063 PUD 1fe7d067 PMD 1ff9f067 PTE 80000000a4244160  Oops: 0000 [#1] SMP DEBUG_PAGEALLOC  CPU 0  Modules linked in: btusb bluetooth brcmsmac brcmutil crc8 cordic b43 radeon(+)  mac80211 cfg80211 ttm ohci_hcd drm_kms_helper rfkill drm ssb agpgart mmc_core  sp5100_tco video battery ac thermal processor rtc_cmos thermal_sys snd_hda_codec_hdmi  joydev snd_hda_codec_conexant button bcma pcmcia snd_hda_intel snd_hda_codec  snd_hwdep snd_pcm shpchp pcmcia_core k8temp snd_timer atl1c snd psmouse hwmon  i2c_piix4 i2c_algo_bit soundcore evdev i2c_core ehci_hcd sg serio_raw snd_page_alloc  loop btrfs

Pid: 1008, comm: modprobe Not tainted 3.3.0-rc1 #21 LENOVO 20046                           /AMD CRB  RIP: 0010:[<ffffffff81275b5b>]  [<ffffffff81275b5b>] memcpy+0xb/0x120  RSP: 0018:ffff8800aa72db00  EFLAGS: 00010246  RAX: ffff8800a4150000 RBX: 0000000000001000 RCX: 0000000000000087  RDX: 0000000000000000 RSI: ffff8800a4244000 RDI: ffff8800a4150bc8  RBP: ffff8800aa72db78 R08: 0000000000000010 R09: ffffffff8174bbec  R10: ffffffff812ee010 R11: 0000000000000001 R12: 0000000000001000  R13: 0000000000010000 R14: ffff8800a4140000 R15: ffff8800aaba1800  FS:  00007ff9a3bd4720(0000) GS:ffff8800afa00000(0000) knlGS:0000000000000000  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b  CR2: ffff8800a4244000 CR3: 00000000a9c18000 CR4: 00000000000006f0  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400  Process modprobe (pid: 1008, threadinfo ffff8800aa72c000, task ffff8800aa0e4000)  Stack:  ffffffffa04e7c7b 0000000000000001 0000000000010000 ffff8800aa72db28  ffffffff00000001 0000000000001000 ffffffff8113cbef 0000000000000020  ffff8800a4243420 ffff880000000002 ffff8800aa72db08 ffff8800a9d42000  Call Trace:  [<ffffffffa04e7c7b>] ? radeon_atrm_get_bios_chunk+0x8b/0xd0 [radeon]  [<ffffffff8113cbef>] ? kmalloc_order_trace+0x3f/0xb0  [<ffffffffa04a9298>] radeon_get_bios+0x68/0x2f0 [radeon]  [<ffffffffa04c7a30>] rv770_init+0x40/0x280 [radeon]  [<ffffffffa047d740>] radeon_device_init+0x560/0x600 [radeon]  [<ffffffffa047ef4f>] radeon_driver_load_kms+0xaf/0x170 [radeon]  [<ffffffffa043cdde>] drm_get_pci_dev+0x18e/0x2c0 [drm]  [<ffffffffa04e7e95>] radeon_pci_probe+0xad/0xb5 [radeon]  [<ffffffff81296c5f>] local_pci_probe+0x5f/0xd0  [<ffffffff81297418>] pci_device_probe+0x88/0xb0  [<ffffffff813417aa>] ? driver_sysfs_add+0x7a/0xb0  [<ffffffff813418d8>] really_probe+0x68/0x180  [<ffffffff81341be5>] driver_probe_device+0x45/0x70  [<ffffffff81341cb3>] __driver_attach+0xa3/0xb0  [<ffffffff81341c10>] ? driver_probe_device+0x70/0x70  [<ffffffff813400ce>] bus_for_each_dev+0x5e/0x90  [<ffffffff8134172e>] driver_attach+0x1e/0x20  [<ffffffff81341298>] bus_add_driver+0xc8/0x280  [<ffffffff813422c6>] driver_register+0x76/0x140  [<ffffffff812976d6>] __pci_register_driver+0x66/0xe0  [<ffffffffa043d021>] drm_pci_init+0x111/0x120 [drm]  [<ffffffff8133c67a>] ? vga_switcheroo_register_handler+0x3a/0x60  [<ffffffffa0229000>] ? 0xffffffffa0228fff  [<ffffffffa02290ec>] radeon_init+0xec/0xee [radeon]  [<ffffffff810002f2>] do_one_initcall+0x42/0x180  [<ffffffff8109d8d2>] sys_init_module+0x92/0x1e0  [<ffffffff815407a9>] system_call_fastpath+0x16/0x1b  Code: 58 2a 43 50 88 43 4e 48 83 c4 08 5b c9 c3 66 90 e8 cb fd ff ff eb  e6 90 90 90 90 90 90 90 90 90 48 89 f8 89 d1 c1 e9 03 83 e2 07 <f3> 48  a5 89 d1 f3 a4 c3 20 48 83 ea 20 4c 8b 06 4c 8b 4e 08 4c  RIP  [<ffffffff81275b5b>] memcpy+0xb/0x120  RSP <ffff8800aa72db00>  CR2: ffff8800a4244000  ---[ end trace fcffa1599cf56382 ]---

Call to acpi_evaluate_object() not always returns 4096 bytes chunks, on my system it can return 2048 bytes chunk, so pass the length of retrieved chunk to memcpy(), not the length of the recieving buffer.

Signed-off-by: Igor Murzov e-mail@date.by

Hi Igor,

I'm not sure I understand, does your BIOS return 2K chunks always or just for the last chunks?

Only for the last chunk. acpi_evaluate_object() returns 16 x 4Kb chunks and then 1 x 2Kb on my laptop. If I revert both my patches (211fa4fc4e13492151e698d92b0dff56b29928ec and a3f83ab1a717c0e6c2f59a4cfdaa10707cc35c55), applying following patch: ----------------------------------------- diff --git a/drivers/gpu/drm/radeon/radeon_atpx_handler.c b/drivers/gpu/drm/radeon/radeon_atpx_handler.c index 9d95792..1376b94 100644 --- a/drivers/gpu/drm/radeon/radeon_atpx_handler.c +++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c @@ -58,6 +58,7 @@ static int radeon_atrm_call(acpi_handle atrm_handle, uint8_t *bios, }

obj = (union acpi_object *)buffer.pointer; + printk(KERN_DEBUG "XXX len: %u, obj->buffer.length: %u", len, obj->buffer.length); memcpy(bios+offset, obj->buffer.pointer, len); kfree(buffer.pointer); return len; -----------------------------------------

gave me following result: ----------------------------------------- # dmesg | grep XXX [ 10.895068] XXX len: 4096, obj->buffer.length: 4096 [ 10.998068] XXX len: 4096, obj->buffer.length: 4096 [ 11.101065] XXX len: 4096, obj->buffer.length: 4096 [ 11.204064] XXX len: 4096, obj->buffer.length: 4096 [ 11.307063] XXX len: 4096, obj->buffer.length: 4096 [ 11.410065] XXX len: 4096, obj->buffer.length: 4096 [ 11.513064] XXX len: 4096, obj->buffer.length: 4096 [ 11.616066] XXX len: 4096, obj->buffer.length: 4096 [ 11.722072] XXX len: 4096, obj->buffer.length: 4096 [ 11.826065] XXX len: 4096, obj->buffer.length: 4096 [ 11.929065] XXX len: 4096, obj->buffer.length: 4096 [ 12.032065] XXX len: 4096, obj->buffer.length: 4096 [ 12.135101] XXX len: 4096, obj->buffer.length: 4096 [ 12.239100] XXX len: 4096, obj->buffer.length: 4096 [ 12.343098] XXX len: 4096, obj->buffer.length: 4096 [ 12.468101] XXX len: 4096, obj->buffer.length: 2048 [ 12.552086] XXX len: 4096, obj->buffer.length: 1 [ 12.636085] XXX len: 4096, obj->buffer.length: 1 [ 12.720089] XXX len: 4096, obj->buffer.length: 1 [ 12.804085] XXX len: 4096, obj->buffer.length: 1 [ 12.888086] XXX len: 4096, obj->buffer.length: 1 [ 12.972088] XXX len: 4096, obj->buffer.length: 1 [ 13.056096] XXX len: 4096, obj->buffer.length: 1 [ 13.140085] XXX len: 4096, obj->buffer.length: 1 [ 13.224088] XXX len: 4096, obj->buffer.length: 1 [ 13.308084] XXX len: 4096, obj->buffer.length: 1 [ 13.392086] XXX len: 4096, obj->buffer.length: 1 [ 13.476089] XXX len: 4096, obj->buffer.length: 1 [ 13.560085] XXX len: 4096, obj->buffer.length: 1 [ 13.644085] XXX len: 4096, obj->buffer.length: 1 [ 13.728090] XXX len: 4096, obj->buffer.length: 1 [ 13.812085] XXX len: 4096, obj->buffer.length: 1 [ 13.896086] XXX len: 4096, obj->buffer.length: 1 [ 13.980088] XXX len: 4096, obj->buffer.length: 1 [ 14.064085] XXX len: 4096, obj->buffer.length: 1 [ 14.148085] XXX len: 4096, obj->buffer.length: 1 [ 14.232089] XXX len: 4096, obj->buffer.length: 1 [ 14.316084] XXX len: 4096, obj->buffer.length: 1 [ 14.400085] XXX len: 4096, obj->buffer.length: 1 [ 14.484089] XXX len: 4096, obj->buffer.length: 1 [ 14.568085] XXX len: 4096, obj->buffer.length: 1 [ 14.652085] XXX len: 4096, obj->buffer.length: 1 [ 14.736089] XXX len: 4096, obj->buffer.length: 1 [ 14.820084] XXX len: 4096, obj->buffer.length: 1 [ 14.905084] XXX len: 4096, obj->buffer.length: 1 [ 14.989088] XXX len: 4096, obj->buffer.length: 1 [ 15.073082] XXX len: 4096, obj->buffer.length: 1 [ 15.158086] XXX len: 4096, obj->buffer.length: 1 [ 15.242089] XXX len: 4096, obj->buffer.length: 1 [ 15.326087] XXX len: 4096, obj->buffer.length: 1 [ 15.410085] XXX len: 4096, obj->buffer.length: 1 [ 15.494088] XXX len: 4096, obj->buffer.length: 1 [ 15.578087] XXX len: 4096, obj->buffer.length: 1 [ 15.662086] XXX len: 4096, obj->buffer.length: 1 [ 15.746088] XXX len: 4096, obj->buffer.length: 1 [ 15.830086] XXX len: 4096, obj->buffer.length: 1 [ 15.914084] XXX len: 4096, obj->buffer.length: 1 [ 15.998087] XXX len: 4096, obj->buffer.length: 1 [ 16.082086] XXX len: 4096, obj->buffer.length: 1 [ 16.166086] XXX len: 4096, obj->buffer.length: 1 [ 16.250087] XXX len: 4096, obj->buffer.length: 1 [ 16.334084] XXX len: 4096, obj->buffer.length: 1 [ 16.418086] XXX len: 4096, obj->buffer.length: 1 [ 16.502088] XXX len: 4096, obj->buffer.length: 1 -----------------------------------------

-- Igor