| Message ID | 20200317152244.442912-2-colin.king@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [SRU,B,E,F] ACPI: sysfs: copy ACPI data using io memory copying | expand |
On Tue, Mar 17, 2020 at 03:22:44PM +0000, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > BugLink: https://bugs.launchpad.net/bugs/1866772 > > Reading ACPI data on ARM64 at a non-aligned offset from > /sys/firmware/acpi/tables/data/BERT will cause a splat because > the data is I/O memory mapped and being read with just a memcpy. > Fix this by introducing an I/O variant of memory_read_from_buffer > and using I/O memory mapped copies instead. > > Fixes the following splat: > > [ 439.789355] Unable to handle kernel paging request at virtual address ffff800041ac0007 > [ 439.797275] Mem abort info: > [ 439.800078] ESR = 0x96000021 > [ 439.803131] EC = 0x25: DABT (current EL), IL = 32 bits > [ 439.808437] SET = 0, FnV = 0 > [ 439.811486] EA = 0, S1PTW = 0 > [ 439.814621] Data abort info: > [ 439.817489] ISV = 0, ISS = 0x00000021 > [ 439.821319] CM = 0, WnR = 0 > [ 439.824282] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000817fc000 > [ 439.830979] [ffff800041ac0007] pgd=000000bffcfff003, pud=0000009f27cee003, pmd=000000bf4b993003, pte=0068000080280703 > [ 439.841584] Internal error: Oops: 96000021 [#1] SMP > [ 439.846449] Modules linked in: nls_iso8859_1 dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua ipmi_ssif input_leds joydev ipmi_devintf ipmi_msghandler thunderx2_pmu sch_fq_codel ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor xor_neon raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus ast i2c_algo_bit crct10dif_ce drm_vram_helper uas ttm ghash_ce drm_kms_helper sha2_ce syscopyarea sha256_arm64 qede sysfillrect mpt3sas sha1_ce sysimgblt fb_sys_fops raid_class qed drm scsi_transport_sas usb_storage ahci crc8 gpio_xlp i2c_xlp9xx hid_generic usbhid hid aes_neon_bs aes_neon_blk aes_ce_blk crypto_simd cryptd aes_ce_cipher > [ 439.908474] CPU: 2 PID: 3926 Comm: a.out Not tainted 5.4.0-14-generic #17-Ubuntu > [ 439.915855] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL027 07/01/2019 > [ 439.923844] pstate: 80400009 (Nzcv daif +PAN -UAO) > [ 439.928625] pc : __memcpy+0x90/0x180 > [ 439.932192] lr : memory_read_from_buffer+0x64/0x88 > [ 439.936968] sp : ffff8000350dbc70 > [ 439.940270] x29: ffff8000350dbc70 x28: ffff009e9c444b00 > [ 439.945568] x27: 0000000000000000 x26: 0000000000000000 > [ 439.950866] x25: 0000000056000000 x24: ffff800041ac0000 > [ 439.956164] x23: ffff009ea163f980 x22: 0000000000000007 > [ 439.961462] x21: ffff8000350dbce8 x20: 000000000000000e > [ 439.966760] x19: 0000000000000007 x18: ffff8000112f64a8 > [ 439.972058] x17: 0000000000000000 x16: 0000000000000000 > [ 439.977355] x15: 0000000080280000 x14: ffff800041aed000 > [ 439.982653] x13: ffff009ee9fa2840 x12: ffff800041ad1000 > [ 439.987951] x11: ffff8000115e1360 x10: ffff8000115e1360 > [ 439.993248] x9 : 0000000000010000 x8 : ffff800011ad2658 > [ 439.998546] x7 : ffff800041ac0000 x6 : ffff009ea163f980 > [ 440.003844] x5 : 0140000000000000 x4 : 0000000000010000 > [ 440.009141] x3 : ffff800041ac0000 x2 : 0000000000000007 > [ 440.014439] x1 : ffff800041ac0007 x0 : ffff009ea163f980 > [ 440.019737] Call trace: > [ 440.022173] __memcpy+0x90/0x180 > [ 440.025392] acpi_data_show+0x54/0x80 > [ 440.029044] sysfs_kf_bin_read+0x6c/0xa8 > [ 440.032954] kernfs_file_direct_read+0x90/0x2d0 > [ 440.037470] kernfs_fop_read+0x68/0x78 > [ 440.041210] __vfs_read+0x48/0x90 > [ 440.044511] vfs_read+0xd0/0x1a0 > [ 440.047726] ksys_read+0x78/0x100 > [ 440.051028] __arm64_sys_read+0x24/0x30 > [ 440.054852] el0_svc_common.constprop.0+0xdc/0x1d8 > [ 440.059629] el0_svc_handler+0x34/0xa0 > [ 440.063366] el0_svc+0x10/0x14 > [ 440.066411] Code: 36180062 f8408423 f80084c3 36100062 (b8404423) > [ 440.072492] ---[ end trace 45fb374e8d2d800e ]--- > > A simple reproducer is as follows: > > int main(void) > { > int fd; > char buffer[7]; > ssize_t n; > > fd = open("/sys/firmware/acpi/tables/data/BERT", O_RDONLY); > if (fd < 0) { > perror("open failed"); > return -1; > } > do { > n = read(fd, buffer, sizeof(buffer)); > } while (n > 0); > > return 0; > } > > Link: https://bugs.launchpad.net/bugs/1866772 > Signed-off-by: Colin Ian King <colin.king@canonical.com> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > (backported from upstream linux-next commit 08c07cefb3042a55bc9f8243814b504d5eff93f3) > Signed-off-by: Colin Ian King <colin.king@canonical.com> So once again I'm not seeing this sha1, or indeed this commit at all, in linux-next. What repo did you cherry pick this from? Also the syntax you should use for the "backported from" line is: (backported from commit 08c07cefb3042a55bc9f8243814b504d5eff93f3 linux-next) We have scripts which look for these strings, and throwing extra text between "from" and "commit" breaks them.
On 20/03/2020 22:04, Seth Forshee wrote: > On Tue, Mar 17, 2020 at 03:22:44PM +0000, Colin King wrote: >> From: Colin Ian King <colin.king@canonical.com> >> >> BugLink: https://bugs.launchpad.net/bugs/1866772 >> >> Reading ACPI data on ARM64 at a non-aligned offset from >> /sys/firmware/acpi/tables/data/BERT will cause a splat because >> the data is I/O memory mapped and being read with just a memcpy. >> Fix this by introducing an I/O variant of memory_read_from_buffer >> and using I/O memory mapped copies instead. >> >> Fixes the following splat: >> >> [ 439.789355] Unable to handle kernel paging request at virtual address ffff800041ac0007 >> [ 439.797275] Mem abort info: >> [ 439.800078] ESR = 0x96000021 >> [ 439.803131] EC = 0x25: DABT (current EL), IL = 32 bits >> [ 439.808437] SET = 0, FnV = 0 >> [ 439.811486] EA = 0, S1PTW = 0 >> [ 439.814621] Data abort info: >> [ 439.817489] ISV = 0, ISS = 0x00000021 >> [ 439.821319] CM = 0, WnR = 0 >> [ 439.824282] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000817fc000 >> [ 439.830979] [ffff800041ac0007] pgd=000000bffcfff003, pud=0000009f27cee003, pmd=000000bf4b993003, pte=0068000080280703 >> [ 439.841584] Internal error: Oops: 96000021 [#1] SMP >> [ 439.846449] Modules linked in: nls_iso8859_1 dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua ipmi_ssif input_leds joydev ipmi_devintf ipmi_msghandler thunderx2_pmu sch_fq_codel ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor xor_neon raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus ast i2c_algo_bit crct10dif_ce drm_vram_helper uas ttm ghash_ce drm_kms_helper sha2_ce syscopyarea sha256_arm64 qede sysfillrect mpt3sas sha1_ce sysimgblt fb_sys_fops raid_class qed drm scsi_transport_sas usb_storage ahci crc8 gpio_xlp i2c_xlp9xx hid_generic usbhid hid aes_neon_bs aes_neon_blk aes_ce_blk crypto_simd cryptd aes_ce_cipher >> [ 439.908474] CPU: 2 PID: 3926 Comm: a.out Not tainted 5.4.0-14-generic #17-Ubuntu >> [ 439.915855] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL027 07/01/2019 >> [ 439.923844] pstate: 80400009 (Nzcv daif +PAN -UAO) >> [ 439.928625] pc : __memcpy+0x90/0x180 >> [ 439.932192] lr : memory_read_from_buffer+0x64/0x88 >> [ 439.936968] sp : ffff8000350dbc70 >> [ 439.940270] x29: ffff8000350dbc70 x28: ffff009e9c444b00 >> [ 439.945568] x27: 0000000000000000 x26: 0000000000000000 >> [ 439.950866] x25: 0000000056000000 x24: ffff800041ac0000 >> [ 439.956164] x23: ffff009ea163f980 x22: 0000000000000007 >> [ 439.961462] x21: ffff8000350dbce8 x20: 000000000000000e >> [ 439.966760] x19: 0000000000000007 x18: ffff8000112f64a8 >> [ 439.972058] x17: 0000000000000000 x16: 0000000000000000 >> [ 439.977355] x15: 0000000080280000 x14: ffff800041aed000 >> [ 439.982653] x13: ffff009ee9fa2840 x12: ffff800041ad1000 >> [ 439.987951] x11: ffff8000115e1360 x10: ffff8000115e1360 >> [ 439.993248] x9 : 0000000000010000 x8 : ffff800011ad2658 >> [ 439.998546] x7 : ffff800041ac0000 x6 : ffff009ea163f980 >> [ 440.003844] x5 : 0140000000000000 x4 : 0000000000010000 >> [ 440.009141] x3 : ffff800041ac0000 x2 : 0000000000000007 >> [ 440.014439] x1 : ffff800041ac0007 x0 : ffff009ea163f980 >> [ 440.019737] Call trace: >> [ 440.022173] __memcpy+0x90/0x180 >> [ 440.025392] acpi_data_show+0x54/0x80 >> [ 440.029044] sysfs_kf_bin_read+0x6c/0xa8 >> [ 440.032954] kernfs_file_direct_read+0x90/0x2d0 >> [ 440.037470] kernfs_fop_read+0x68/0x78 >> [ 440.041210] __vfs_read+0x48/0x90 >> [ 440.044511] vfs_read+0xd0/0x1a0 >> [ 440.047726] ksys_read+0x78/0x100 >> [ 440.051028] __arm64_sys_read+0x24/0x30 >> [ 440.054852] el0_svc_common.constprop.0+0xdc/0x1d8 >> [ 440.059629] el0_svc_handler+0x34/0xa0 >> [ 440.063366] el0_svc+0x10/0x14 >> [ 440.066411] Code: 36180062 f8408423 f80084c3 36100062 (b8404423) >> [ 440.072492] ---[ end trace 45fb374e8d2d800e ]--- >> >> A simple reproducer is as follows: >> >> int main(void) >> { >> int fd; >> char buffer[7]; >> ssize_t n; >> >> fd = open("/sys/firmware/acpi/tables/data/BERT", O_RDONLY); >> if (fd < 0) { >> perror("open failed"); >> return -1; >> } >> do { >> n = read(fd, buffer, sizeof(buffer)); >> } while (n > 0); >> >> return 0; >> } >> >> Link: https://bugs.launchpad.net/bugs/1866772 >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >> (backported from upstream linux-next commit 08c07cefb3042a55bc9f8243814b504d5eff93f3) >> Signed-off-by: Colin Ian King <colin.king@canonical.com> > > So once again I'm not seeing this sha1, or indeed this commit at all, in > linux-next. What repo did you cherry pick this from? > > Also the syntax you should use for the "backported from" line is: > > (backported from commit 08c07cefb3042a55bc9f8243814b504d5eff93f3 linux-next) My Bad. Note that this got dropped from linux-next so that SHA is no longer in the tree. It got dropped from linux-next because the acpi component was being added without the fs/libfs.c part being added causing build failures in integration. Hence this now should be a SAUCE patch. Colin > > We have scripts which look for these strings, and throwing extra text > between "from" and "commit" breaks them. >
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index c60d2c6..fb9e216 100644 --- a/drivers/acpi/sysfs.c +++ b/drivers/acpi/sysfs.c @@ -446,7 +446,7 @@ static ssize_t acpi_data_show(struct file *filp, struct kobject *kobj, base = acpi_os_map_memory(data_attr->addr, data_attr->attr.size); if (!base) return -ENOMEM; - rc = memory_read_from_buffer(buf, count, &offset, base, + rc = memory_read_from_io_buffer(buf, count, &offset, base, data_attr->attr.size); acpi_os_unmap_memory(base, data_attr->attr.size); diff --git a/fs/libfs.c b/fs/libfs.c index 1463b03..96db15f 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -730,6 +730,39 @@ ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, } EXPORT_SYMBOL(memory_read_from_buffer); +/** + * memory_read_from_io_buffer - copy data from a io memory mapped buffer + * @to: the kernel space buffer to read to + * @count: the maximum number of bytes to read + * @ppos: the current position in the buffer + * @from: the buffer to read from + * @available: the size of the buffer + * + * The memory_read_from_buffer() function reads up to @count bytes from the + * io memory mappy buffer @from at offset @ppos into the kernel space address + * starting at @to. + * + * On success, the number of bytes read is returned and the offset @ppos is + * advanced by this number, or negative value is returned on error. + **/ +ssize_t memory_read_from_io_buffer(void *to, size_t count, loff_t *ppos, + const void *from, size_t available) +{ + loff_t pos = *ppos; + + if (pos < 0) + return -EINVAL; + if (pos >= available) + return 0; + if (count > available - pos) + count = available - pos; + memcpy_fromio(to, from + pos, count); + *ppos = pos + count; + + return count; +} +EXPORT_SYMBOL(memory_read_from_io_buffer); + /* * Transaction based IO. * The file expects a single write which triggers the transaction, and then diff --git a/include/linux/string.h b/include/linux/string.h index b6ccdc2..04089a9 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -215,6 +215,8 @@ int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, const void *from, size_t available); +extern ssize_t memory_read_from_io_buffer(void *to, size_t count, loff_t *ppos, + const void *from, size_t available); /** * strstarts - does @str start with @prefix?