4.9-stable review patch. If anyone has any objections, please let me know.
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From: Stanislaw Gruszka sgruszka@redhat.com
commit 4e50ce03976fbc8ae995a000c4b10c737467beaa upstream.
Take into account that sg->offset can be bigger than PAGE_SIZE when setting segment sg->dma_address. Otherwise sg->dma_address will point at diffrent page, what makes DMA not possible with erros like this:
xhci_hcd 0000:38:00.3: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0000 address=0x00000000fdaa70c0 flags=0x0020] xhci_hcd 0000:38:00.3: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0000 address=0x00000000fdaa7040 flags=0x0020] xhci_hcd 0000:38:00.3: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0000 address=0x00000000fdaa7080 flags=0x0020] xhci_hcd 0000:38:00.3: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0000 address=0x00000000fdaa7100 flags=0x0020] xhci_hcd 0000:38:00.3: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0000 address=0x00000000fdaa7000 flags=0x0020]
Additinally with wrong sg->dma_address unmap_sg will free wrong pages, what what can cause crashes like this:
Feb 28 19:27:45 kernel: BUG: Bad page state in process cinnamon pfn:39e8b1 Feb 28 19:27:45 kernel: Disabling lock debugging due to kernel taint Feb 28 19:27:45 kernel: flags: 0x2ffff0000000000() Feb 28 19:27:45 kernel: raw: 02ffff0000000000 0000000000000000 ffffffff00000301 0000000000000000 Feb 28 19:27:45 kernel: raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 Feb 28 19:27:45 kernel: page dumped because: nonzero _refcount Feb 28 19:27:45 kernel: Modules linked in: ccm fuse arc4 nct6775 hwmon_vid amdgpu nls_iso8859_1 nls_cp437 edac_mce_amd vfat fat kvm_amd ccp rng_core kvm mt76x0u mt76x0_common mt76x02_usb irqbypass mt76_usb mt76x02_lib mt76 crct10dif_pclmul crc32_pclmul chash mac80211 amd_iommu_v2 ghash_clmulni_intel gpu_sched i2c_algo_bit ttm wmi_bmof snd_hda_codec_realtek snd_hda_codec_generic drm_kms_helper snd_hda_codec_hdmi snd_hda_intel drm snd_hda_codec aesni_intel snd_hda_core snd_hwdep aes_x86_64 crypto_simd snd_pcm cfg80211 cryptd mousedev snd_timer glue_helper pcspkr r8169 input_leds realtek agpgart libphy rfkill snd syscopyarea sysfillrect sysimgblt fb_sys_fops soundcore sp5100_tco k10temp i2c_piix4 wmi evdev gpio_amdpt pinctrl_amd mac_hid pcc_cpufreq acpi_cpufreq sg ip_tables x_tables ext4(E) crc32c_generic(E) crc16(E) mbcache(E) jbd2(E) fscrypto(E) sd_mod(E) hid_generic(E) usbhid(E) hid(E) dm_mod(E) serio_raw(E) atkbd(E) libps2(E) crc32c_intel(E) ahci(E) libahci(E) libata(E) xhci_pci(E) xhci_hcd(E) Feb 28 19:27:45 kernel: scsi_mod(E) i8042(E) serio(E) bcache(E) crc64(E) Feb 28 19:27:45 kernel: CPU: 2 PID: 896 Comm: cinnamon Tainted: G B W E 4.20.12-arch1-1-custom #1 Feb 28 19:27:45 kernel: Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./B450M Pro4, BIOS P1.20 06/26/2018 Feb 28 19:27:45 kernel: Call Trace: Feb 28 19:27:45 kernel: dump_stack+0x5c/0x80 Feb 28 19:27:45 kernel: bad_page.cold.29+0x7f/0xb2 Feb 28 19:27:45 kernel: __free_pages_ok+0x2c0/0x2d0 Feb 28 19:27:45 kernel: skb_release_data+0x96/0x180 Feb 28 19:27:45 kernel: __kfree_skb+0xe/0x20 Feb 28 19:27:45 kernel: tcp_recvmsg+0x894/0xc60 Feb 28 19:27:45 kernel: ? reuse_swap_page+0x120/0x340 Feb 28 19:27:45 kernel: ? ptep_set_access_flags+0x23/0x30 Feb 28 19:27:45 kernel: inet_recvmsg+0x5b/0x100 Feb 28 19:27:45 kernel: __sys_recvfrom+0xc3/0x180 Feb 28 19:27:45 kernel: ? handle_mm_fault+0x10a/0x250 Feb 28 19:27:45 kernel: ? syscall_trace_enter+0x1d3/0x2d0 Feb 28 19:27:45 kernel: ? __audit_syscall_exit+0x22a/0x290 Feb 28 19:27:45 kernel: __x64_sys_recvfrom+0x24/0x30 Feb 28 19:27:45 kernel: do_syscall_64+0x5b/0x170 Feb 28 19:27:45 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xa9
Cc: stable@vger.kernel.org Reported-and-tested-by: Jan Viktorin jan.viktorin@gmail.com Reviewed-by: Alexander Duyck alexander.h.duyck@linux.intel.com Signed-off-by: Stanislaw Gruszka sgruszka@redhat.com Fixes: 80187fd39dcb ('iommu/amd: Optimize map_sg and unmap_sg') Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iommu/amd_iommu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -2599,7 +2599,12 @@ static int map_sg(struct device *dev, st
/* Everything is mapped - write the right values into s->dma_address */ for_each_sg(sglist, s, nelems, i) { - s->dma_address += address + s->offset; + /* + * Add in the remaining piece of the scatter-gather offset that + * was masked out when we were determining the physical address + * via (sg_phys(s) & PAGE_MASK) earlier. + */ + s->dma_address += address + (s->offset & ~PAGE_MASK); s->dma_length = s->length; }