| Message ID | 20200312111345.1057569-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | ACPI: sysfs: copy ACPI data using io memory copying | expand |
On Thursday, March 12, 2020 12:13:45 PM CET Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > 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: > > #include <sys/types.h> > #include <sys/stat.h> > #include <fcntl.h> > #include <unistd.h> > #include <stdio.h> > #include <string.h> > > 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; > } > > BugLink: https://bugs.launchpad.net/bugs/1866772 > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/acpi/sysfs.c | 2 +- > fs/libfs.c | 33 +++++++++++++++++++++++++++++++++ > include/linux/string.h | 2 ++ > 3 files changed, 36 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c > index c60d2c6d31d6..fb9e216cb8c0 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 c686bd9caac6..3e112c51ce7b 100644 > --- a/fs/libfs.c > +++ b/fs/libfs.c > @@ -800,6 +800,39 @@ 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 6dfbb2efa815..0c6ec2aa3909 100644 > --- a/include/linux/string.h > +++ b/include/linux/string.h > @@ -216,6 +216,8 @@ 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); > > int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); > > Applied as 5.7 material, thanks!
On 14/03/2020 10:23, Rafael J. Wysocki wrote: > On Thursday, March 12, 2020 12:13:45 PM CET Colin King wrote: >> From: Colin Ian King <colin.king@canonical.com> >> >> 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: >> >> #include <sys/types.h> >> #include <sys/stat.h> >> #include <fcntl.h> >> #include <unistd.h> >> #include <stdio.h> >> #include <string.h> >> >> 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; >> } >> >> BugLink: https://bugs.launchpad.net/bugs/1866772 >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> --- >> drivers/acpi/sysfs.c | 2 +- >> fs/libfs.c | 33 +++++++++++++++++++++++++++++++++ >> include/linux/string.h | 2 ++ >> 3 files changed, 36 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c >> index c60d2c6d31d6..fb9e216cb8c0 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 c686bd9caac6..3e112c51ce7b 100644 >> --- a/fs/libfs.c >> +++ b/fs/libfs.c >> @@ -800,6 +800,39 @@ 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 6dfbb2efa815..0c6ec2aa3909 100644 >> --- a/include/linux/string.h >> +++ b/include/linux/string.h >> @@ -216,6 +216,8 @@ 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); >> >> int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); >> >> > > Applied as 5.7 material, thanks! > > > > Hi, what's the state of this patch, it got applied but I don't see it in 5.7, 5.8 or 5.8-rc3? Colin
On Wed, Sep 2, 2020 at 12:30 PM Colin Ian King <colin.king@canonical.com> wrote: > > On 14/03/2020 10:23, Rafael J. Wysocki wrote: > > On Thursday, March 12, 2020 12:13:45 PM CET Colin King wrote: > >> From: Colin Ian King <colin.king@canonical.com> > >> > >> 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: > >> > >> #include <sys/types.h> > >> #include <sys/stat.h> > >> #include <fcntl.h> > >> #include <unistd.h> > >> #include <stdio.h> > >> #include <string.h> > >> > >> 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; > >> } > >> > >> BugLink: https://bugs.launchpad.net/bugs/1866772 > >> Signed-off-by: Colin Ian King <colin.king@canonical.com> > >> --- > >> drivers/acpi/sysfs.c | 2 +- > >> fs/libfs.c | 33 +++++++++++++++++++++++++++++++++ > >> include/linux/string.h | 2 ++ > >> 3 files changed, 36 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c > >> index c60d2c6d31d6..fb9e216cb8c0 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 c686bd9caac6..3e112c51ce7b 100644 > >> --- a/fs/libfs.c > >> +++ b/fs/libfs.c > >> @@ -800,6 +800,39 @@ 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 6dfbb2efa815..0c6ec2aa3909 100644 > >> --- a/include/linux/string.h > >> +++ b/include/linux/string.h > >> @@ -216,6 +216,8 @@ 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); > >> > >> int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); > >> > >> > > > > Applied as 5.7 material, thanks! > > > > > > > > > Hi, what's the state of this patch, it got applied but I don't see it in > 5.7, 5.8 or 5.8-rc3? > s/5.8-rc3/5.9-rc3 - Sedat -
From: Colin Ian King > Sent: 02 September 2020 11:27 > > On 14/03/2020 10:23, Rafael J. Wysocki wrote: > > On Thursday, March 12, 2020 12:13:45 PM CET Colin King wrote: > >> From: Colin Ian King <colin.king@canonical.com> > >> > >> 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. .. > >> +/** > >> + * 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. > >> + **/ Apart from the return value how is this different from the generic memcpy_from_io() ? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On 02/09/2020 12:13, David Laight wrote: > From: Colin Ian King >> Sent: 02 September 2020 11:27 >> >> On 14/03/2020 10:23, Rafael J. Wysocki wrote: >>> On Thursday, March 12, 2020 12:13:45 PM CET Colin King wrote: >>>> From: Colin Ian King <colin.king@canonical.com> >>>> >>>> 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. > .. >>>> +/** >>>> + * 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. >>>> + **/ > > Apart from the return value how is this different from the generic > memcpy_from_io() ? > > David The intention is to be semantically the same as memory_read_from_buffer(), so in that respect quite a bit different from memcpy_fromio() Colin > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales) >
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index c60d2c6d31d6..fb9e216cb8c0 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 c686bd9caac6..3e112c51ce7b 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -800,6 +800,39 @@ 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 6dfbb2efa815..0c6ec2aa3909 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -216,6 +216,8 @@ 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); int ptr_to_hashval(const void *ptr, unsigned long *hashval_out);