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path: root/drivers/firmware/efi/efivars.c
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* efi: Don't use spinlocks for efi varsSylvain Chouleur2016-09-091-4/+18
| | | | | | | | | | | | | | | | | | | | | All efivars operations are protected by a spinlock which prevents interruptions and preemption. This is too restricted, we just need a lock preventing concurrency. The idea is to use a semaphore of count 1 and to have two ways of locking, depending on the context: - In interrupt context, we call down_trylock(), if it fails we return an error - In normal context, we call down_interruptible() We don't use a mutex here because the mutex_trylock() function must not be called from interrupt context, whereas the down_trylock() can. Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
* efi: Merge boolean flag argumentsJulia Lawall2016-05-071-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The parameters atomic and duplicates of efivar_init always have opposite values. Drop the parameter atomic, replace the uses of !atomic with duplicates, and update the call sites accordingly. The code using duplicates is slightly reorganized with an 'else', to avoid duplicating the lock code. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Saurabh Sengar <saurabh.truth@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vaishali Thakkar <vaishali.thakkar@oracle.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462570771-13324-5-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* drivers/firmware/efi/efivars.c: use in_compat_syscall() to check for compat ↵Andy Lutomirski2016-03-221-1/+1
| | | | | | | | | | | | | callers This should make no difference on any architecture, as x86's historical is_compat_task behavior really did check whether the calling syscall was a compat syscall. x86's is_compat_task is going away, though. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'v4.5-rc5' into efi/core, before queueing up new changesIngo Molnar2016-02-221-21/+14
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * efi: Make our variable validation list include the guidPeter Jones2016-02-101-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All the variables in this list so far are defined to be in the global namespace in the UEFI spec, so this just further ensures we're validating the variables we think we are. Including the guid for entries will become more important in future patches when we decide whether or not to allow deletion of variables based on presence in this list. Signed-off-by: Peter Jones <pjones@redhat.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
| * efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad versionPeter Jones2016-02-101-19/+11
| | | | | | | | | | | | | | | | | | | | Translate EFI's UCS-2 variable names to UTF-8 instead of just assuming all variable names fit in ASCII. Signed-off-by: Peter Jones <pjones@redhat.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
* | efivars: Use to_efivar_entryGeliang Tang2016-02-031-1/+1
|/ | | | | | | | | Use to_efivar_entry() instead of open-coding it. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Link: http://lkml.kernel.org/r/1454364428-494-9-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* efi: efivar_create_sysfs_entry() should return negative error codesDan Carpenter2015-04-301-5/+6
| | | | | | | | | It's not very normal to return 1 on failure and 0 on success. There isn't a reason for it here, the callers don't care so long as it's non-zero on failure. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efi: Rename efi_guid_unparse to efi_guid_to_strBorislav Petkov2015-01-071-3/+3
| | | | | | | Call it what it does - "unparse" is plain-misleading. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
* efi: Autoload efivarsLee, Chun-Yi2014-07-181-0/+1
| | | | | | | | | | | | | | | | | | | | | The original patch is from Ben Hutchings's contribution to debian kernel. Got Ben's permission to remove the code of efi-pstore.c and send to linux-efi: https://github.com/BlankOn/linux-debian/blob/master/debian/patches/features/all/efi-autoload-efivars.patch efivars is generally useful to have on EFI systems, and in some cases it may be impossible to load it after a kernel upgrade in order to complete a boot loader update. At the same time we don't want to waste memory on non-EFI systems by making them built-in. Instead, give them module aliases as if they are platform drivers, and register a corresponding platform device whenever EFI runtime services are available. This should trigger udev to load them. Signed-off-by: Lee, Chun-Yi <jlee@suse.com> Cc: Ben Hutchings <ben@decadent.org.uk> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars: Add compatibility code for compat tasksMatt Fleming2014-04-171-26/+116
| | | | | | | | | | | | | It seems people are using 32-bit efibootmgr on top of 64-bit kernels, which will currently fail horribly when using the efivars interface, which is the traditional efibootmgr backend (the other being efivarfs). Since there is no versioning info in the data structure, figure out when we need to munge the structure data via judicious use of is_compat_task(). Cc: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars: Refactor sanity checking code into separate functionMatt Fleming2014-04-171-20/+32
| | | | | | | | Move a large chunk of code that checks the validity of efi_variable into a new function, because we'll also need to use it for the compat code. Cc: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars: Stop passing a struct argument to efivar_validate()Matt Fleming2014-04-171-2/+4
| | | | | | | | | | In preparation for compat support, we can't assume that user variable object is represented by a 'struct efi_variable'. Convert the validation functions to take the variable name as an argument, which is the only piece of the struct that was ever used anyway. Cc: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars: Check size of user objectMatt Fleming2014-04-171-0/+6
| | | | | | | | | Unbelieavably there are no checks to see whether the data structure passed to 'new_var' and 'del_var' is the size that we expect. Let's add some for better robustness. Cc: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars: Use local variables instead of a pointer dereferenceMatt Fleming2014-04-171-13/+35
| | | | | | | | | In order to support a compat interface we need to stop passing pointers to structures around, since the type of structure is going to depend on whether the current task is a compat task. Cc: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efi: Use NULL instead of 0 for pointerDaeseok Youn2014-03-041-1/+1
| | | | | | | | | | | | Fix following sparse warnings: drivers/firmware/efi/efivars.c:230:66: warning: Using plain integer as NULL pointer drivers/firmware/efi/efi.c:236:27: warning: Using plain integer as NULL pointer Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is ↵Seiji Aguchi2013-11-281-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | completed Currently, when mounting pstore file system, a read callback of efi_pstore driver runs mutiple times as below. - In the first read callback, scan efivar_sysfs_list from head and pass a kmsg buffer of a entry to an upper pstore layer. - In the second read callback, rescan efivar_sysfs_list from the entry and pass another kmsg buffer to it. - Repeat the scan and pass until the end of efivar_sysfs_list. In this process, an entry is read across the multiple read function calls. To avoid race between the read and erasion, the whole process above is protected by a spinlock, holding in open() and releasing in close(). At the same time, kmemdup() is called to pass the buffer to pstore filesystem during it. And then, it causes a following lockdep warning. To make the dynamic memory allocation runnable without taking spinlock, holding off a deletion of sysfs entry if it happens while scanning it via efi_pstore, and deleting it after the scan is completed. To implement it, this patch introduces two flags, scanning and deleting, to efivar_entry. On the code basis, it seems that all the scanning and deleting logic is not needed because __efivars->lock are not dropped when reading from the EFI variable store. But, the scanning and deleting logic is still needed because an efi-pstore and a pstore filesystem works as follows. In case an entry(A) is found, the pointer is saved to psi->data. And efi_pstore_read() passes the entry(A) to a pstore filesystem by releasing __efivars->lock. And then, the pstore filesystem calls efi_pstore_read() again and the same entry(A), which is saved to psi->data, is used for resuming to scan a sysfs-list. So, to protect the entry(A), the logic is needed. [ 1.143710] ------------[ cut here ]------------ [ 1.144058] WARNING: CPU: 1 PID: 1 at kernel/lockdep.c:2740 lockdep_trace_alloc+0x104/0x110() [ 1.144058] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) [ 1.144058] Modules linked in: [ 1.144058] CPU: 1 PID: 1 Comm: systemd Not tainted 3.11.0-rc5 #2 [ 1.144058] 0000000000000009 ffff8800797e9ae0 ffffffff816614a5 ffff8800797e9b28 [ 1.144058] ffff8800797e9b18 ffffffff8105510d 0000000000000080 0000000000000046 [ 1.144058] 00000000000000d0 00000000000003af ffffffff81ccd0c0 ffff8800797e9b78 [ 1.144058] Call Trace: [ 1.144058] [<ffffffff816614a5>] dump_stack+0x54/0x74 [ 1.144058] [<ffffffff8105510d>] warn_slowpath_common+0x7d/0xa0 [ 1.144058] [<ffffffff8105517c>] warn_slowpath_fmt+0x4c/0x50 [ 1.144058] [<ffffffff8131290f>] ? vsscanf+0x57f/0x7b0 [ 1.144058] [<ffffffff810bbd74>] lockdep_trace_alloc+0x104/0x110 [ 1.144058] [<ffffffff81192da0>] __kmalloc_track_caller+0x50/0x280 [ 1.144058] [<ffffffff815147bb>] ? efi_pstore_read_func.part.1+0x12b/0x170 [ 1.144058] [<ffffffff8115b260>] kmemdup+0x20/0x50 [ 1.144058] [<ffffffff815147bb>] efi_pstore_read_func.part.1+0x12b/0x170 [ 1.144058] [<ffffffff81514800>] ? efi_pstore_read_func.part.1+0x170/0x170 [ 1.144058] [<ffffffff815148b4>] efi_pstore_read_func+0xb4/0xe0 [ 1.144058] [<ffffffff81512b7b>] __efivar_entry_iter+0xfb/0x120 [ 1.144058] [<ffffffff8151428f>] efi_pstore_read+0x3f/0x50 [ 1.144058] [<ffffffff8128d7ba>] pstore_get_records+0x9a/0x150 [ 1.158207] [<ffffffff812af25c>] ? selinux_d_instantiate+0x1c/0x20 [ 1.158207] [<ffffffff8128ce30>] ? parse_options+0x80/0x80 [ 1.158207] [<ffffffff8128ced5>] pstore_fill_super+0xa5/0xc0 [ 1.158207] [<ffffffff811ae7d2>] mount_single+0xa2/0xd0 [ 1.158207] [<ffffffff8128ccf8>] pstore_mount+0x18/0x20 [ 1.158207] [<ffffffff811ae8b9>] mount_fs+0x39/0x1b0 [ 1.158207] [<ffffffff81160550>] ? __alloc_percpu+0x10/0x20 [ 1.158207] [<ffffffff811c9493>] vfs_kern_mount+0x63/0xf0 [ 1.158207] [<ffffffff811cbb0e>] do_mount+0x23e/0xa20 [ 1.158207] [<ffffffff8115b51b>] ? strndup_user+0x4b/0xf0 [ 1.158207] [<ffffffff811cc373>] SyS_mount+0x83/0xc0 [ 1.158207] [<ffffffff81673cc2>] system_call_fastpath+0x16/0x1b [ 1.158207] ---[ end trace 61981bc62de9f6f4 ]--- Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Tested-by: Madper Xie <cxie@redhat.com> Cc: stable@kernel.org Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars: Mark local function as staticBojan Prtvar2013-09-051-1/+1
| | | | | | | | This fixes the following sparse warning drivers/firmware/efi/efivars.c:567:6: warning: symbol 'efivars_sysfs_exit' was not declared. Should it be static? Signed-off-by: Bojan Prtvar <prtvar.b@gmail.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivars: check for EFI_RUNTIME_SERVICESMatt Fleming2013-07-111-0/+3
| | | | | | | | | | | | The efivars code requires EFI runtime services to function, so check that they are enabled. This fixes a crash when booting with the "noefi" kernel parameter, and also when mixing kernel and firmware "bitness", e.g. 32-bit kernel with 64-bit firmware. Tested-by: Dave Young <dyoung@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efivar: fix oops in efivar_update_sysfs_entries() caused by memory reuseSeiji Aguchi2013-05-131-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The loop in efivar_update_sysfs_entries() reuses the same allocation for entries each time it calls efivar_create_sysfs_entry(entry). This is wrong because efivar_create_sysfs_entry() expects to keep the memory it was passed, so the caller may not free it (and may not pass the same memory in multiple times). This leads to the oops below. Fix by getting a new allocation each time we go around the loop. ---[ end trace ba4907d5c519d111 ]--- BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8142f81f>] efivar_entry_find+0x14f/0x2d0 PGD 0 Oops: 0000 [#2] SMP Modules linked in: oops(OF+) ebtable_nat ebtables xt_CHECKSUM [...] CPU: 0 PID: 301 Comm: kworker/0:2 Tainted: GF D O 3.9.0+ #1 Hardware name: LENOVO 4291EV7/4291EV7, BIOS 8DET52WW (1.22 ) 09/15/2011 Workqueue: events efivar_update_sysfs_entries task: ffff8801955920c0 ti: ffff88019413e000 task.ti: ffff88019413e000 RIP: 0010:[<ffffffff8142f81f>] [<ffffffff8142f81f>] efivar_entry_find+0x14f/0x2d0 RSP: 0018:ffff88019413fa48 EFLAGS: 00010006 RAX: 0000000000000000 RBX: ffff880195d87c00 RCX: ffffffff81ab6f60 RDX: ffff88019413fb88 RSI: 0000000000000400 RDI: ffff880196254000 RBP: ffff88019413fbd8 R08: 0000000000000000 R09: ffff8800dad99037 R10: ffff880195d87c00 R11: 0000000000000430 R12: ffffffff81ab6f60 R13: fffffffffffff7d8 R14: ffff880196254000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88019e200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000001a0b000 CR4: 00000000000407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88019413fb78 ffff88019413fb88 ffffffff81e85d60 03000000972b5c00 ffff88019413fa29 ffffffff81e85d60 ffff88019413fbfb 0000000197087280 00000000000000fe 0000000000000001 ffffffff81e85dd9 ffff880197087280 Call Trace: [<ffffffff81254371>] ? idr_get_empty_slot+0x131/0x240 [<ffffffff8125b6d2>] ? put_dec+0x72/0x90 [<ffffffff81158e40>] ? cache_alloc_refill+0x170/0x2f0 [<ffffffff81430420>] efivar_update_sysfs_entry+0x150/0x220 [<ffffffff8103dd29>] ? efi_call2+0x9/0x70 [<ffffffff8103d787>] ? virt_efi_get_next_variable+0x47/0x1b0 [<ffffffff8115a8df>] ? kmem_cache_alloc_trace+0x1af/0x1c0 [<ffffffff81430033>] efivar_init+0x2c3/0x380 [<ffffffff814302d0>] ? efivar_delete+0xd0/0xd0 [<ffffffff8143111f>] efivar_update_sysfs_entries+0x6f/0x90 [<ffffffff810605f3>] process_one_work+0x183/0x490 [<ffffffff81061780>] worker_thread+0x120/0x3a0 [<ffffffff81061660>] ? manage_workers+0x160/0x160 [<ffffffff8106752e>] kthread+0xce/0xe0 [<ffffffff81067460>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff81543c5c>] ret_from_fork+0x7c/0xb0 [<ffffffff81067460>] ? kthread_freezable_should_stop+0x70/0x70 Code: 8d 55 b0 48 8d 45 a0 49 81 ed 28 08 00 00 48 89 95 78 fe [...] RIP [<ffffffff8142f81f>] efivar_entry_find+0x14f/0x2d0 RSP <ffff88019413fa48> CR2: 0000000000000000 ---[ end trace ba4907d5c519d112 ]--- Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-05-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS updates from Al Viro, Misc cleanups all over the place, mainly wrt /proc interfaces (switch create_proc_entry to proc_create(), get rid of the deprecated create_proc_read_entry() in favor of using proc_create_data() and seq_file etc). 7kloc removed. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits) don't bother with deferred freeing of fdtables proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h proc: Make the PROC_I() and PDE() macros internal to procfs proc: Supply a function to remove a proc entry by PDE take cgroup_open() and cpuset_open() to fs/proc/base.c ppc: Clean up scanlog ppc: Clean up rtas_flash driver somewhat hostap: proc: Use remove_proc_subtree() drm: proc: Use remove_proc_subtree() drm: proc: Use minor->index to label things, not PDE->name drm: Constify drm_proc_list[] zoran: Don't print proc_dir_entry data in debug reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show() proc: Supply an accessor for getting the data from a PDE's parent airo: Use remove_proc_subtree() rtl8192u: Don't need to save device proc dir PDE rtl8187se: Use a dir under /proc/net/r8180/ proc: Add proc_mkdir_data() proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h} proc: Move PDE_NET() to fs/proc/proc_net.c ...
* efi: remove "kfree(NULL)"Dan Carpenter2013-04-301-3/+1
| | | | | | | No need to free a NULL pointer. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* Merge tag 'v3.9' into efi-for-tip2Matt Fleming2013-04-301-1/+2
| | | | | | | | | | Resolve conflicts for Ingo. Conflicts: drivers/firmware/Kconfig drivers/firmware/efivars.c Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* efi: split efisubsystem from efivarsTom Gundersen2013-04-171-0/+617
This registers /sys/firmware/efi/{,systab,efivars/} whenever EFI is enabled and the system is booted with EFI. This allows *) userspace to check for the existence of /sys/firmware/efi as a way to determine whether or it is running on an EFI system. *) 'mount -t efivarfs none /sys/firmware/efi/efivars' without manually loading any modules. [ Also, move the efivar API into vars.c and unconditionally compile it. This allows us to move efivars.c, which now only contains the sysfs variable code, into the firmware/efi directory. Note that the efivars.c filename is kept to maintain backwards compatability with the old efivars.ko module. With this patch it is now possible for efivarfs to be built without CONFIG_EFI_VARS - Matt ] Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Mike Waychison <mikew@google.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Chun-Yi Lee <jlee@suse.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Tobias Powalowski <tpowa@archlinux.org> Signed-off-by: Tom Gundersen <teg@jklm.no> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
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