lwn.git/fs/pstore, branch standardize-docs

pstore: use memdup_user

2017-06-28T00:02:36+00:00

Use memdup_user() helper instead of open-coding to simplify the code. Signed-off-by: Geliang Tang Signed-off-by: Kees Cook

pstore: Fix format string to use %u for record id

2017-05-31T17:13:45+00:00

The format string for record->id (u64) was using %lld instead of %llu. Signed-off-by: Kees Cook

pstore: Populate pstore record->time field

2017-05-31T17:13:44+00:00

The current time will be initially available in the record->time field for all pstore_read() and pstore_write() calls. Backends can either update the field during read(), or use the field during write() instead of fetching time themselves. Signed-off-by: Kees Cook

pstore: Create common record initializer

2017-05-31T17:13:44+00:00

In preparation for setting timestamps in the pstore core, create a common initializer routine, instead of using static initializers. Signed-off-by: Kees Cook

pstore: Avoid potential infinite loop

2017-05-31T17:13:42+00:00

If a backend does not correctly iterate through its records, pstore will get stuck loading entries. Detect this with a large record count, and announce if we ever hit the limit. This will let future backend reading bugs less annoying to debug. Additionally adjust the error about pstore_mkfile() failing. Signed-off-by: Kees Cook

pstore: Fix leaked pstore_record in pstore_get_backend_records()

2017-05-31T17:10:09+00:00

When the "if (record->size <= 0)" test is true in pstore_get_backend_records() it's pretty clear that nobody holds a reference to the allocated pstore_record, yet we don't free it. Let's free it. Fixes: 2a2b0acf768c ("pstore: Allocate records on heap instead of stack") Signed-off-by: Douglas Anderson Signed-off-by: Kees Cook Cc: stable@vger.kernel.org

pstore: Don't warn if data is uncompressed and type is not PSTORE_TYPE_DMESG

2017-05-31T17:09:32+00:00

commit 9abdcccc3d5f ("pstore: Extract common arguments into structure") moved record decompression to function. decompress_record() gets called without checking type and compressed flag. Warning will be reported if data is uncompressed. Pstore type PSTORE_TYPE_PPC_OPAL, PSTORE_TYPE_PPC_COMMON doesn't contain compressed data and warning get printed part of dmesg. Partial dmesg log: [ 35.848914] pstore: ignored compressed record type 6 [ 35.848927] pstore: ignored compressed record type 8 Above warning should not get printed as it is known that data won't be compressed for above type and it is valid condition. This patch returns if data is not compressed and print warning only if data is compressed and type is not PSTORE_TYPE_DMESG. Reported-by: Anton Blanchard Signed-off-by: Ankit Kumar Reviewed-by: Mahesh Salgaonkar Signed-off-by: Kees Cook Fixes: 9abdcccc3d5f ("pstore: Extract common arguments into structure") Cc: stable@vger.kernel.org

Merge tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

2017-05-11T02:13:03+00:00

Pull hw lockdown support from David Howells: "Annotation of module parameters that configure hardware resources including ioports, iomem addresses, irq lines and dma channels. This allows a future patch to prohibit the use of such module parameters to prevent that hardware from being abused to gain access to the running kernel image as part of locking the kernel down under UEFI secure boot conditions. Annotations are made by changing: module_param(n, t, p) module_param_named(n, v, t, p) module_param_array(n, t, m, p) to: module_param_hw(n, t, hwtype, p) module_param_hw_named(n, v, t, hwtype, p) module_param_hw_array(n, t, hwtype, m, p) where the module parameter refers to a hardware setting hwtype specifies the type of the resource being configured. This can be one of: ioport Module parameter configures an I/O port iomem Module parameter configures an I/O mem address ioport_or_iomem Module parameter could be either (runtime set) irq Module parameter configures an I/O port dma Module parameter configures a DMA channel dma_addr Module parameter configures a DMA buffer address other Module parameter configures some other value Note that the hwtype is compile checked, but not currently stored (the lockdown code probably won't require it). It is, however, there for future use. A bonus is that the hwtype can also be used for grepping. The intention is for the kernel to ignore or reject attempts to set annotated module parameters if lockdown is enabled. This applies to options passed on the boot command line, passed to insmod/modprobe or direct twiddling in /sys/module/ parameter files. The module initialisation then needs to handle the parameter not being set, by (1) giving an error, (2) probing for a value or (3) using a reasonable default. What I can't do is just reject a module out of hand because it may take a hardware setting in the module parameters. Some important modules, some ipmi stuff for instance, both probe for hardware and allow hardware to be manually specified; if the driver is aborts with any error, you don't get any ipmi hardware. Further, trying to do this entirely in the module initialisation code doesn't protect against sysfs twiddling. [!] Note that in and of itself, this series of patches should have no effect on the the size of the kernel or code execution - that is left to a patch in the next series to effect. It does mark annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in an already existing field" * tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits) Annotate hardware config module parameters in sound/pci/ Annotate hardware config module parameters in sound/oss/ Annotate hardware config module parameters in sound/isa/ Annotate hardware config module parameters in sound/drivers/ Annotate hardware config module parameters in fs/pstore/ Annotate hardware config module parameters in drivers/watchdog/ Annotate hardware config module parameters in drivers/video/ Annotate hardware config module parameters in drivers/tty/ Annotate hardware config module parameters in drivers/staging/vme/ Annotate hardware config module parameters in drivers/staging/speakup/ Annotate hardware config module parameters in drivers/staging/media/ Annotate hardware config module parameters in drivers/scsi/ Annotate hardware config module parameters in drivers/pcmcia/ Annotate hardware config module parameters in drivers/pci/hotplug/ Annotate hardware config module parameters in drivers/parport/ Annotate hardware config module parameters in drivers/net/wireless/ Annotate hardware config module parameters in drivers/net/wan/ Annotate hardware config module parameters in drivers/net/irda/ Annotate hardware config module parameters in drivers/net/hamradio/ Annotate hardware config module parameters in drivers/net/ethernet/ ...

pstore: Solve lockdep warning by moving inode locks

2017-04-28T03:35:34+00:00

Lockdep complains about a possible deadlock between mount and unlink (which is technically impossible), but fixing this improves possible future multiple-backend support, and keeps locking in the right order. The lockdep warning could be triggered by unlinking a file in the pstore filesystem: -> #1 (&sb->s_type->i_mutex_key#14){++++++}: lock_acquire+0xc9/0x220 down_write+0x3f/0x70 pstore_mkfile+0x1f4/0x460 pstore_get_records+0x17a/0x320 pstore_fill_super+0xa4/0xc0 mount_single+0x89/0xb0 pstore_mount+0x13/0x20 mount_fs+0xf/0x90 vfs_kern_mount+0x66/0x170 do_mount+0x190/0xd50 SyS_mount+0x90/0xd0 entry_SYSCALL_64_fastpath+0x1c/0xb1 -> #0 (&psinfo->read_mutex){+.+.+.}: __lock_acquire+0x1ac0/0x1bb0 lock_acquire+0xc9/0x220 __mutex_lock+0x6e/0x990 mutex_lock_nested+0x16/0x20 pstore_unlink+0x3f/0xa0 vfs_unlink+0xb5/0x190 do_unlinkat+0x24c/0x2a0 SyS_unlinkat+0x16/0x30 entry_SYSCALL_64_fastpath+0x1c/0xb1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#14); lock(&psinfo->read_mutex); lock(&sb->s_type->i_mutex_key#14); lock(&psinfo->read_mutex); Reported-by: Marta Lofstedt Reported-by: Chris Wilson Signed-off-by: Kees Cook Acked-by: Namhyung Kim

pstore: Remove unused vmalloc.h in pmsg

2017-04-27T21:48:59+00:00

Since the vmalloc code has been removed from write_pmsg() in the commit "5bf6d1b pstore/pmsg: drop bounce buffer", remove the unused header vmalloc.h. Signed-off-by: Geliang Tang Signed-off-by: Kees Cook