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2013-07-03dmi: add support for exact DMI matches in addition to substring matchingJani Nikula1-3/+9
dmi_match() considers a substring match to be a successful match. This is not always sufficient to distinguish between DMI data for different systems. Add support for exact string matching using strcmp() in addition to the substring matching using strstr(). The specific use case in the i915 driver is to allow us to use an exact match for D510MO, without also incorrectly matching D510MOV: { .ident = "Intel D510MO", .matches = { DMI_MATCH(DMI_BOARD_VENDOR, "Intel"), DMI_EXACT_MATCH(DMI_BOARD_NAME, "D510MO"), }, } Signed-off-by: Jani Nikula <jani.nikula@intel.com> Cc: <annndddrr@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Cornel Panceac <cpanceac@gmail.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-17Merge 3.10-rc6 into driver-core-nextGreg Kroah-Hartman1-5/+3
We want these fixes here too. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03dell_rbu: Select CONFIG_FW_LOADER_USER_HELPER explicitlyTakashi Iwai1-0/+1
The usermode helper is mandatory for this driver. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-13efivar: fix oops in efivar_update_sysfs_entries() caused by memory reuseSeiji Aguchi1-5/+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>
2013-05-01Merge branch 'for-linus' of ↵Linus Torvalds2-0/+2
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 ...
2013-05-01Merge branch 'x86-efi-for-linus' of ↵Linus Torvalds10-2171/+2103
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/efi changes from Peter Anvin: "The bulk of these changes are cleaning up the efivars handling and breaking it up into a tree of files. There are a number of fixes as well. The entire changeset is pretty big, but most of it is code movement. Several of these commits are quite new; the history got very messed up due to a mismerge with the urgent changes for rc8 which completely broke IA64, and so Ingo requested that we rebase it to straighten it out." * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: remove "kfree(NULL)" efi: locking fix in efivar_entry_set_safe() efi, pstore: Read data from variable store before memcpy() efi, pstore: Remove entry from list when erasing efi, pstore: Initialise 'entry' before iterating efi: split efisubsystem from efivars efivarfs: Move to fs/efivarfs efivars: Move pstore code into the new EFI directory efivars: efivar_entry API efivars: Keep a private global pointer to efivars efi: move utf16 string functions to efi.h x86, efi: Make efi_memblock_x86_reserve_range more readable efivarfs: convert to use simple_open()
2013-04-30dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()Ben Hutchings1-43/+37
Move the calls to memcpy_fromio() up into the loop in dmi_scan_machine(), and move the signature checks back down into dmi_decode(). We need to check at 16-byte intervals but keep a 32-byte buffer for an SMBIOS entry, so shift the buffer after each iteration. Merge smbios_present() into dmi_present(), so we look for an SMBIOS signature at the beginning of the given buffer and then for a DMI signature at an offset of 16 bytes. [artem.savkov@gmail.com: use proper buf type in dmi_present()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Reported-by: Tim McGrath <tmhikaru@gmail.com> Tested-by: Tim Mcgrath <tmhikaru@gmail.com> Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Artem Savkov <artem.savkov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30dump_stack: implement arch-specific hardware description in task dumpsTejun Heo1-0/+13
x86 and ia64 can acquire extra hardware identification information from DMI and print it along with task dumps; however, the usage isn't consistent. * x86 show_regs() collects vendor, product and board strings and print them out with PID, comm and utsname. Some of the information is printed again later in the same dump. * warn_slowpath_common() explicitly accesses the DMI board and prints it out with "Hardware name:" label. This applies to both x86 and ia64 but is irrelevant on all other archs. * ia64 doesn't show DMI information on other non-WARN dumps. This patch introduces arch-specific hardware description used by dump_stack(). It can be set by calling dump_stack_set_arch_desc() during boot and, if exists, printed out in a separate line with "Hardware name:" label. dmi_set_dump_stack_arch_desc() is added which sets arch-specific description from DMI data. It uses dmi_ids_string[] which is set from dmi_present() used for DMI debug message. It is superset of the information x86 show_regs() is using. The function is called from x86 and ia64 boot code right after dmi_scan_machine(). This makes the explicit DMI handling in warn_slowpath_common() unnecessary. Removed. show_regs() isn't yet converted to use generic debug information printing and this patch doesn't remove the duplicate DMI handling in x86 show_regs(). The next patch will unify show_regs() handling and remove the duplication. An example WARN dump follows. WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505() Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #3 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48 ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a08e 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58 Call Trace: [<ffffffff81c614dc>] dump_stack+0x19/0x1b [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0 [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8234a0c3>] init_workqueues+0x35/0x505 ... v2: Use the same string as the debug message from dmi_present() which also contains BIOS information. Move hardware name into its own line as warn_slowpath_common() did. This change was suggested by Bjorn Helgaas. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30dmi: morph dmi_dump_ids() into dmi_format_ids() which formats into a bufferTejun Heo1-17/+27
We're goning to use DMI identification for other purposes too. Morph dmi_dump_ids() which is used to print DMI identification as a debug message during boot into dmi_format_ids() which formats the same information sans the leading "DMI:" tag into a string buffer. dmi_present() is updated to format the information into dmi_ids_string[] using the new function and print it with "DMI:" prefix. dmi_ids_string[] will be used for another purpose by a future patch. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30efi: remove "kfree(NULL)"Dan Carpenter1-3/+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>
2013-04-30efi: locking fix in efivar_entry_set_safe()Dan Carpenter1-3/+5
The intent is that if we aren't allowed to block because we're in an NMI or an emergency then we only take the lock if it is uncontended. Part of the problem is the test is reversed so we return -EBUSY if we acquire the lock. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-30efi, pstore: Read data from variable store before memcpy()Matt Fleming2-23/+28
Seiji reported getting empty dmesg-* files, because the data was never actually read in efi_pstore_read_func(), and so the memcpy() was copying garbage data. This patch necessitated adding __efivar_entry_get() which is callable between efivar_entry_iter_{begin,end}(). We can also delete __efivar_entry_size() because efi_pstore_read_func() was the only caller. Reported-by: Seiji Aguchi <seiji.aguchi@hds.com> Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-30efi, pstore: Remove entry from list when erasingMatt Fleming1-0/+2
We need to remove the entry from the EFI variable list before we erase it from the variable store and free the associated state, otherwise it's possible to hit the following crash, BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8142ea0f>] __efivar_entry_iter+0xcf/0x120 PGD 19483f067 PUD 195426067 PMD 0 Oops: 0000 [#1] SMP [...] Call Trace: [<ffffffff81430ebf>] efi_pstore_erase+0xef/0x140 [<ffffffff81003138>] ? math_error+0x288/0x2d0 [<ffffffff811ea491>] pstore_unlink+0x41/0x60 [<ffffffff811741ff>] vfs_unlink+0x9f/0x110 [<ffffffff8117813b>] do_unlinkat+0x18b/0x280 [<ffffffff8116d7e6>] ? sys_newfstatat+0x36/0x50 [<ffffffff81178472>] sys_unlinkat+0x22/0x40 [<ffffffff81543282>] system_call_fastpath+0x16/0x1b Reported-by: Seiji Aguchi <seiji.aguchi@hds.com> Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-30efi, pstore: Initialise 'entry' before iteratingMatt Fleming1-1/+1
Seiji reports hitting the following crash when erasing pstore dump variables, BUG: unable to handle kernel NULL pointer dereference at 0000000000000fa4 IP: [<ffffffff8142dadf>] __efivar_entry_iter+0x2f/0x120 PGD 18482a067 PUD 190724067 PMD 0 Oops: 0000 [#1] SMP [...] Call Trace: [<ffffffff8143001f>] efi_pstore_erase+0xdf/0x130 [<ffffffff81200038>] ? cap_socket_create+0x8/0x10 [<ffffffff811ea491>] pstore_unlink+0x41/0x60 [<ffffffff811741ff>] vfs_unlink+0x9f/0x110 [<ffffffff8117813b>] do_unlinkat+0x18b/0x280 [<ffffffff81178472>] sys_unlinkat+0x22/0x40 [<ffffffff81542402>] system_call_fastpath+0x16/0x1b 'entry' needs to be initialised in efi_pstore_erase() when iterating with __efivar_entry_iter(), otherwise the garbage pointer will be dereferenced, leading to crashes like the above. Reported-by: Seiji Aguchi <seiji.aguchi@hds.com> Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-30Merge tag 'v3.9' into efi-for-tip2Matt Fleming5-35/+27
Resolve conflicts for Ingo. Conflicts: drivers/firmware/Kconfig drivers/firmware/efivars.c Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-29firmware, memmap: fix firmware_map_entry leakYasuaki Ishimatsu1-6/+3
When hot removing memory, a firmware_map_entry which has memory range of the memory is released by release_firmware_map_entry(). If the entry is allocated by bootmem, release_firmware_map_entry() adds the entry to map_entires_bootmem list when firmware_map_find_entry() finds the entry from map_entries list. But firmware_map_find_entry never find the entry sicne map_entires list does not have the entry. So the entry just leaks. Here are steps of leaking firmware_map_entry: firmware_map_remove() -> firmware_map_find_entry() Find released entry from map_entries list -> firmware_map_remove_entry() Delete the entry from map_entries list -> remove_sysfs_fw_map_entry() ... -> release_firmware_map_entry() -> firmware_map_find_entry() Find the entry from map_entries list but the entry has been deleted from map_entries list. So the entry is not added to map_entries_bootmem. Thus the entry leaks release_firmware_map_entry() should not call firmware_map_find_entry() since releaed entry has been deleted from map_entries list. So the patch delete firmware_map_find_entry() from releae_firmware_map_entry() Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29Include missing linux/magic.h inclusionsDavid Howells1-0/+1
Include missing linux/magic.h inclusions where the source file is currently expecting to get magic numbers through linux/proc_fs.h. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-efi@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-26efivars: only check for duplicates on the registered listMatt Fleming1-5/+7
variable_is_present() accesses '__efivars' directly, but when called via gsmi_init() Michel reports observing the following crash, BUG: unable to handle kernel NULL pointer dereference at (null) IP: variable_is_present+0x55/0x170 Call Trace: register_efivars+0x106/0x370 gsmi_init+0x2ad/0x3da do_one_initcall+0x3f/0x170 The reason for the crash is that '__efivars' hasn't been initialised nor has it been registered with register_efivars() by the time the google EFI SMI driver runs. The gsmi code uses its own struct efivars, and therefore, a different variable list. Fix the above crash by passing the registered struct efivars to variable_is_present(), so that we traverse the correct list. Reported-by: Michel Lespinasse <walken@google.com> Tested-by: Michel Lespinasse <walken@google.com> Cc: Mike Waychison <mikew@google.com> Cc: Matthew Garrett <matthew.garrett@nebula.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-17efi: split efisubsystem from efivarsTom Gundersen5-758/+765
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>
2013-04-17efivarfs: Move to fs/efivarfsMatt Fleming1-496/+0
Now that efivarfs uses the efivar API, move it out of efivars.c and into fs/efivarfs where it belongs. This move will eventually allow us to enable the efivarfs code without having to also enable CONFIG_EFI_VARS built, and vice versa. Furthermore, things like, mount -t efivarfs none /sys/firmware/efi/efivars will now work if efivarfs is built as a module without requiring the use of MODULE_ALIAS(), which would have been necessary when the efivarfs code was part of efivars.c. Cc: Matthew Garrett <matthew.garrett@nebula.com> Cc: Jeremy Kerr <jk@ozlabs.org> Reviewed-by: Tom Gundersen <teg@jklm.no> Tested-by: Tom Gundersen <teg@jklm.no> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-17efivars: Move pstore code into the new EFI directoryMatt Fleming6-300/+301
efivars.c has grown far too large and needs to be divided up. Create a new directory and move the persistence storage code to efi-pstore.c now that it uses the new efivar API. This helps us to greatly reduce the size of efivars.c and paves the way for moving other code out of efivars.c. Note that because CONFIG_EFI_VARS can be built as a module efi-pstore must also include support for building as a module. Reviewed-by: Tom Gundersen <teg@jklm.no> Tested-by: Tom Gundersen <teg@jklm.no> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-17efivars: efivar_entry APIMatt Fleming2-723/+1107
There isn't really a formal interface for dealing with EFI variables or struct efivar_entry. Historically, this has led to various bits of code directly accessing the generic EFI variable ops, which inherently ties it to specific EFI variable operations instead of indirectly using whatever ops were registered with register_efivars(). This lead to the efivarfs code only working with the generic EFI variable ops and not CONFIG_GOOGLE_SMI. Encapsulate everything that needs to access '__efivars' inside an efivar_entry_* API and use the new API in the pstore, sysfs and efivarfs code. Much of the efivars code had to be rewritten to use this new API. For instance, it is now up to the users of the API to build the initial list of EFI variables in their efivar_init() callback function. The variable list needs to be passed to efivar_init() which allows us to keep work arounds for things like implementation bugs in GetNextVariable() in a central location. Allowing users of the API to use a callback function to build the list greatly benefits the efivarfs code which needs to allocate inodes and dentries for every variable. It previously did this in a racy way because the code ran without holding the variable spinlock. Both the sysfs and efivarfs code maintain their own lists which means the two interfaces can be running simultaneously without interference, though it should be noted that because no synchronisation is performed it is very easy to create inconsistencies. efibootmgr doesn't currently use efivarfs and users are likely to also require the old sysfs interface, so it makes sense to allow both to be built. Reviewed-by: Tom Gundersen <teg@jklm.no> Tested-by: Tom Gundersen <teg@jklm.no> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-17efivars: Keep a private global pointer to efivarsMatt Fleming1-34/+46
Some machines have an EFI variable interface that does not conform to the UEFI specification, e.g. CONFIG_GOOGLE_SMI. Add the necessary code so that it's only possible to use one implementation of EFI variable operations at runtime. This allows us to keep a single (file-scope) global pointer 'struct efivars', which simplifies access. This will hopefully dissuade developers from accessing the generic operations struct directly in the future, as was done in the efivarfs and pstore code, thereby allowing future code to work with both the generic efivar ops and the google SMI ops. This may seem like a step backwards in terms of modularity, but we don't need to track more than one 'struct efivars' at one time. There is no synchronisation done between multiple EFI variable operations, and according to Mike no one is using both the generic EFI var ops and CONFIG_GOOGLE_SMI simultaneously, though a single kernel build _does_ need to able to support both. It also helps to clearly highlight which functions form the core of the efivars interface - those that require access to __efivars. Reviewed-by: Tom Gundersen <teg@jklm.no> Tested-by: Tom Gundersen <teg@jklm.no> Acked-by: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-17efi: move utf16 string functions to efi.hMatt Fleming2-32/+4
There are currently two implementations of the utf16 string functions. Somewhat confusingly, they've got different names. Centralise the functions in efi.h. Reviewed-by: Tom Gundersen <teg@jklm.no> Tested-by: Tom Gundersen <teg@jklm.no> Reviewed-by: Mike Waychison <mikew@google.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-15Move utf16 functions to kernel core and renameMatthew Garrett2-62/+19
We want to be able to use the utf16 functions that are currently present in the EFI variables code in platform-specific code as well. Move them to the kernel core, and in the process rename them to accurately describe what they do - they don't handle UTF16, only UCS2. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-09x86, efivars: firmware bug workarounds should be in platform codeMatt Fleming1-15/+3
Let's not burden ia64 with checks in the common efivars code that we're not writing too much data to the variable store. That kind of thing is an x86 firmware bug, plain and simple. efi_query_variable_store() provides platforms with a wrapper in which they can perform checks and workarounds for EFI variable storage bugs. Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-22efivars: Fix check for CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLEBen Hutchings1-1/+1
The 'CONFIG_' prefix is not implicit in IS_ENABLED(). Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-21efivars: Handle duplicate names from get_next_variable()Matt Fleming1-1/+47
Some firmware exhibits a bug where the same VariableName and VendorGuid values are returned on multiple invocations of GetNextVariableName(). See, https://bugzilla.kernel.org/show_bug.cgi?id=47631 As a consequence of such a bug, Andre reports hitting the following WARN_ON() in the sysfs code after updating the BIOS on his, "Gigabyte Technology Co., Ltd. To be filled by O.E.M./Z77X-UD3H, BIOS F19e 11/21/2012)" machine, [ 0.581554] EFI Variables Facility v0.08 2004-May-17 [ 0.584914] ------------[ cut here ]------------ [ 0.585639] WARNING: at /home/andre/linux/fs/sysfs/dir.c:536 sysfs_add_one+0xd4/0x100() [ 0.586381] Hardware name: To be filled by O.E.M. [ 0.587123] sysfs: cannot create duplicate filename '/firmware/efi/vars/SbAslBufferPtrVar-01f33c25-764d-43ea-aeea-6b5a41f3f3e8' [ 0.588694] Modules linked in: [ 0.589484] Pid: 1, comm: swapper/0 Not tainted 3.8.0+ #7 [ 0.590280] Call Trace: [ 0.591066] [<ffffffff81208954>] ? sysfs_add_one+0xd4/0x100 [ 0.591861] [<ffffffff810587bf>] warn_slowpath_common+0x7f/0xc0 [ 0.592650] [<ffffffff810588bc>] warn_slowpath_fmt+0x4c/0x50 [ 0.593429] [<ffffffff8134dd85>] ? strlcat+0x65/0x80 [ 0.594203] [<ffffffff81208954>] sysfs_add_one+0xd4/0x100 [ 0.594979] [<ffffffff81208b78>] create_dir+0x78/0xd0 [ 0.595753] [<ffffffff81208ec6>] sysfs_create_dir+0x86/0xe0 [ 0.596532] [<ffffffff81347e4c>] kobject_add_internal+0x9c/0x220 [ 0.597310] [<ffffffff81348307>] kobject_init_and_add+0x67/0x90 [ 0.598083] [<ffffffff81584a71>] ? efivar_create_sysfs_entry+0x61/0x1c0 [ 0.598859] [<ffffffff81584b2b>] efivar_create_sysfs_entry+0x11b/0x1c0 [ 0.599631] [<ffffffff8158517e>] register_efivars+0xde/0x420 [ 0.600395] [<ffffffff81d430a7>] ? edd_init+0x2f5/0x2f5 [ 0.601150] [<ffffffff81d4315f>] efivars_init+0xb8/0x104 [ 0.601903] [<ffffffff8100215a>] do_one_initcall+0x12a/0x180 [ 0.602659] [<ffffffff81d05d80>] kernel_init_freeable+0x13e/0x1c6 [ 0.603418] [<ffffffff81d05586>] ? loglevel+0x31/0x31 [ 0.604183] [<ffffffff816a6530>] ? rest_init+0x80/0x80 [ 0.604936] [<ffffffff816a653e>] kernel_init+0xe/0xf0 [ 0.605681] [<ffffffff816ce7ec>] ret_from_fork+0x7c/0xb0 [ 0.606414] [<ffffffff816a6530>] ? rest_init+0x80/0x80 [ 0.607143] ---[ end trace 1609741ab737eb29 ]--- There's not much we can do to work around and keep traversing the variable list once we hit this firmware bug. Our only solution is to terminate the loop because, as Lingzhu reports, some machines get stuck when they encounter duplicate names, > I had an IBM System x3100 M4 and x3850 X5 on which kernel would > get stuck in infinite loop creating duplicate sysfs files because, > for some reason, there are several duplicate boot entries in nvram > getting GetNextVariableName into a circle of iteration (with > period > 2). Also disable the workqueue, as efivar_update_sysfs_entries() uses GetNextVariableName() to figure out which variables have been created since the last iteration. That algorithm isn't going to work if GetNextVariableName() returns duplicates. Note that we don't disable EFI variable creation completely on the affected machines, it's just that any pstore dump-* files won't appear in sysfs until the next boot. Reported-by: Andre Heider <a.heider@gmail.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Tested-by: Lingzhu Xiang <lxiang@redhat.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-21efivars: explicitly calculate length of VariableNameMatt Fleming1-1/+31
It's not wise to assume VariableNameSize represents the length of VariableName, as not all firmware updates VariableNameSize in the same way (some don't update it at all if EFI_SUCCESS is returned). There are even implementations out there that update VariableNameSize with values that are both larger than the string returned in VariableName and smaller than the buffer passed to GetNextVariableName(), which resulted in the following bug report from Michael Schroeder, > On HP z220 system (firmware version 1.54), some EFI variables are > incorrectly named : > > ls -d /sys/firmware/efi/vars/*8be4d* | grep -v -- -8be returns > /sys/firmware/efi/vars/dbxDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > /sys/firmware/efi/vars/KEKDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > /sys/firmware/efi/vars/SecureBoot-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > /sys/firmware/efi/vars/SetupMode-Information8be4df61-93ca-11d2-aa0d-00e098032b8c The issue here is that because we blindly use VariableNameSize without verifying its value, we can potentially read garbage values from the buffer containing VariableName if VariableNameSize is larger than the length of VariableName. Since VariableName is a string, we can calculate its size by searching for the terminating NULL character. Reported-by: Frederic Crozat <fcrozat@suse.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Michael Schroeder <mls@suse.com> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Lingzhu Xiang <lxiang@redhat.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-21efivars: Add module parameter to disable use as a pstore backendSeth Forshee2-1/+16
We know that with some firmware implementations writing too much data to UEFI variables can lead to bricking machines. Recent changes attempt to address this issue, but for some it may still be prudent to avoid writing large amounts of data until the solution has been proven on a wide variety of hardware. Crash dumps or other data from pstore can potentially be a large data source. Add a pstore_module parameter to efivars to allow disabling its use as a backend for pstore. Also add a config option, CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE, to allow setting the default value of this paramter to true (i.e. disabled by default). Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-21efivars: Allow disabling use as a pstore backendSeth Forshee2-44/+29
Add a new option, CONFIG_EFI_VARS_PSTORE, which can be set to N to avoid using efivars as a backend to pstore, as some users may want to compile out the code completely. Set the default to Y to maintain backwards compatability, since this feature has always been enabled until now. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-09Merge branch 'for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace bugfixes from Eric Biederman: "This is three simple fixes against 3.9-rc1. I have tested each of these fixes and verified they work correctly. The userns oops in key_change_session_keyring and the BUG_ON triggered by proc_ns_follow_link were found by Dave Jones. I am including the enhancement for mount to only trigger requests of filesystem modules here instead of delaying this for the 3.10 merge window because it is both trivial and the kind of change that tends to bit-rot if left untouched for two months." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Use nd_jump_link in proc_ns_follow_link fs: Limit sys_mount to only request filesystem modules (Part 2). fs: Limit sys_mount to only request filesystem modules. userns: Stop oopsing in key_change_session_keyring
2013-03-08dmi_scan: fix missing check for _DMI_ signature in smbios_present()Ben Hutchings1-3/+2
Commit 9f9c9cbb6057 ("drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists") hoisted the check for "_DMI_" into dmi_scan_machine(), which means that we don't bother to check for "_DMI_" at offset 16 in an SMBIOS entry. smbios_present() may also call dmi_present() for an address where we found "_SM_", if it failed further validation. Check for "_DMI_" in smbios_present() before calling dmi_present(). [akpm@linux-foundation.org: fix build] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Reported-by: Tim McGrath <tmhikaru@gmail.com> Tested-by: Tim Mcgrath <tmhikaru@gmail.com> Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-06efivarfs: return accurate error code in efivarfs_fill_super()Matt Fleming1-5/+15
Joseph was hitting a failure case when mounting efivarfs which resulted in an incorrect error message, $ sudo mount -v /sys/firmware/efi/efivars mount: Cannot allocate memory triggered when efivarfs_valid_name() returned -EINVAL. Make sure we pass accurate return values up the stack if efivarfs_fill_super() fails to build inodes for EFI variables. Reported-by: Joseph Yasi <joe.yasi@gmail.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: <stable@vger.kernel.org> # v3.8 Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-06efivars: efivarfs_valid_name() should handle pstore syntaxMatt Fleming1-2/+2
Stricter validation was introduced with commit da27a24383b2b ("efivarfs: guid part of filenames are case-insensitive") and commit 47f531e8ba3b ("efivarfs: Validate filenames much more aggressively"), which is necessary for the guid portion of efivarfs filenames, but we don't need to be so strict with the first part, the variable name. The UEFI specification doesn't impose any constraints on variable names other than they be a NULL-terminated string. The above commits caused a regression that resulted in users seeing the following message, $ sudo mount -v /sys/firmware/efi/efivars mount: Cannot allocate memory whenever pstore EFI variables were present in the variable store, since their variable names failed to pass the following check, /* GUID should be right after the first '-' */ if (s - 1 != strchr(str, '-')) as a typical pstore filename is of the form, dump-type0-10-1-<guid>. The fix is trivial since the guid portion of the filename is GUID_LEN bytes, we can use (len - GUID_LEN) to ensure the '-' character is where we expect it to be. (The bogus ENOMEM error value will be fixed in a separate patch.) Reported-by: Joseph Yasi <joe.yasi@gmail.com> Tested-by: Joseph Yasi <joe.yasi@gmail.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: <stable@vger.kernel.org> # v3.8 Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-06efi: be more paranoid about available space when creating variablesMatthew Garrett1-27/+79
UEFI variables are typically stored in flash. For various reasons, avaiable space is typically not reclaimed immediately upon the deletion of a variable - instead, the system will garbage collect during initialisation after a reboot. Some systems appear to handle this garbage collection extremely poorly, failing if more than 50% of the system flash is in use. This can result in the machine refusing to boot. The safest thing to do for the moment is to forbid writes if they'd end up using more than half of the storage space. We can make this more finegrained later if we come up with a method for identifying the broken machines. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> Cc: Josh Boyer <jwboyer@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-03-03fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman1-0/+1
Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-27Merge branch 'x86-efi-for-linus' of ↵Linus Torvalds1-8/+138
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/EFI changes from Peter Anvin: - Improve the initrd handling in the EFI boot stub by allowing forward slashes in the pathname - from Chun-Yi Lee. - Cleanup code duplication in the EFI mixed kernel/firmware code - from Satoru Takeuchi. - efivarfs bug fixes for more strict filename validation, with lots of input from Al Viro. * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, efi: remove duplicate code in setup_arch() by using, efi_is_native() efivarfs: guid part of filenames are case-insensitive efivarfs: Validate filenames much more aggressively efivarfs: Use sizeof() instead of magic number x86, efi: Allow slash in file path of initrd
2013-02-23memory-hotplug: remove /sys/firmware/memmap/X sysfsYasuaki Ishimatsu1-13/+183
When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type} sysfs files are created. But there is no code to remove these files. This patch implements the function to remove them. We cannot free firmware_map_entry which is allocated by bootmem because there is no way to do so when the system is up. But we can at least remember the address of that memory and reuse the storage when the memory is added next time. This patch also introduces a new list map_entries_bootmem to link the map entries allocated by bootmem when they are removed, and a lock to protect it. And these entries will be reused when the memory is hot-added again. The idea is suggestted by Andrew Morton. NOTE: It is unsafe to return an entry pointer and release the map_entries_lock. So we should not hold the map_entries_lock separately in firmware_map_find_entry() and firmware_map_remove_entry(). Hold the map_entries_lock across find and remove /sys/firmware/memmap/X operation. And also, users of these two functions need to be careful to hold the lock when using these two functions. [tangchen@cn.fujitsu.com: Hold spinlock across find|remove /sys operation] [tangchen@cn.fujitsu.com: fix the wrong comments of map_entries] [tangchen@cn.fujitsu.com: reuse the storage of /sys/firmware/memmap/X/ allocated by bootmem] [tangchen@cn.fujitsu.com: fix section mismatch problem] [tangchen@cn.fujitsu.com: fix the doc format in drivers/firmware/memmap.c] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Julian Calaby <julian.calaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21Merge tag 'please-pull-pstore' of ↵Linus Torvalds1-47/+133
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux Pull pstore patches from Tony Luck: "A few fixes to reduce places where pstore might hang a system in the crash path. Plus a new mountpoint (/sys/fs/pstore ... makes more sense then /dev/pstore)." Fix up trivial conflict in drivers/firmware/efivars.c * tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: pstore: Create a convenient mount point for pstore efi_pstore: Introducing workqueue updating sysfs efivars: Disable external interrupt while holding efivars->lock efi_pstore: Avoid deadlock in non-blocking paths pstore: Avoid deadlock in panic and emergency-restart path
2013-02-12efi_pstore: Introducing workqueue updating sysfsSeiji Aguchi1-5/+80
[Problem] efi_pstore creates sysfs entries, which enable users to access to NVRAM, in a write callback. If a kernel panic happens in an interrupt context, it may fail because it could sleep due to dynamic memory allocations during creating sysfs entries. [Patch Description] This patch removes sysfs operations from a write callback by introducing a workqueue updating sysfs entries which is scheduled after the write callback is called. Also, the workqueue is kicked in a just oops case. A system will go down in other cases such as panic, clean shutdown and emergency restart. And we don't need to create sysfs entries because there is no chance for users to access to them. efi_pstore will be robust against a kernel panic in an interrupt context with this patch. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2013-02-12efivars: Disable external interrupt while holding efivars->lockSeiji Aguchi1-42/+44
[Problem] There is a scenario which efi_pstore fails to log messages in a panic case. - CPUA holds an efi_var->lock in either efivarfs parts or efi_pstore with interrupt enabled. - CPUB panics and sends IPI to CPUA in smp_send_stop(). - CPUA stops with holding the lock. - CPUB kicks efi_pstore_write() via kmsg_dump(KSMG_DUMP_PANIC) but it returns without logging messages. [Patch Description] This patch disables an external interruption while holding efivars->lock as follows. In efi_pstore_write() and get_var_data(), spin_lock/spin_unlock is replaced by spin_lock_irqsave/spin_unlock_irqrestore because they may be called in an interrupt context. In other functions, they are replaced by spin_lock_irq/spin_unlock_irq. because they are all called from a process context. By applying this patch, we can avoid the problem above with a following senario. - CPUA holds an efi_var->lock with interrupt disabled. - CPUB panics and sends IPI to CPUA in smp_send_stop(). - CPUA receives the IPI after releasing the lock because it is disabling interrupt while holding the lock. - CPUB waits for one sec until CPUA releases the lock. - CPUB kicks efi_pstore_write() via kmsg_dump(KSMG_DUMP_PANIC) And it can hold the lock successfully. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Mike Waychison <mikew@google.com> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2013-02-12efivarfs: guid part of filenames are case-insensitiveMatt Fleming1-2/+93
It makes no sense to treat the following filenames as unique, VarName-abcdefab-abcd-abcd-abcd-abcdefabcdef VarName-ABCDEFAB-ABCD-ABCD-ABCD-ABCDEFABCDEF VarName-ABcDEfAB-ABcD-ABcD-ABcD-ABcDEfABcDEf VarName-aBcDEfAB-aBcD-aBcD-aBcD-aBcDEfaBcDEf ... etc ... since the guid will be converted into a binary representation, which has no case. Roll our own dentry operations so that we can treat the variable name part of filenames ("VarName" in the above example) as case-sensitive, but the guid portion as case-insensitive. That way, efivarfs will refuse to create the above files if any one already exists. Reported-by: Lingzhu Xiang <lxiang@redhat.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Jeremy Kerr <jeremy.kerr@canonical.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-02-12efivarfs: Validate filenames much more aggressivelyMatt Fleming1-5/+44
The only thing that efivarfs does to enforce a valid filename is ensure that the name isn't too short. We need to strongly sanitise any filenames, not least because variable creation is delayed until efivarfs_file_write(), which means we can't rely on the firmware to inform us of an invalid name, because if the file is never written to we'll never know it's invalid. Perform a couple of steps before agreeing to create a new file, * hex_to_bin() returns a value indicating whether or not it was able to convert its arguments to a binary representation - we should check it. * Ensure that the GUID portion of the filename is the correct length and format. * The variable name portion of the filename needs to be at least one character in size. Reported-by: Lingzhu Xiang <lxiang@redhat.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Jeremy Kerr <jeremy.kerr@canonical.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-01-31efivarfs: Use sizeof() instead of magic numberMatt Fleming1-1/+1
Instead of adding a magic 4 to the variable size, use sizeof() to make it explicitly clear what the quantity represents (the variable's attributes). CC: Jeremy Kerr <jeremy.kerr@canonical.com> Cc: Chun-Yi Lee <joeyli.kernel@gmail.com> Cc: Andy Whitcroft <apw@canonical.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-01-31Merge branch 'x86-efi-for-linus' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 EFI fixes from Peter Anvin: "This is a collection of fixes for the EFI support. The controversial bit here is a set of patches which bumps the boot protocol version as part of fixing some serious problems with the EFI handover protocol, used when booting under EFI using a bootloader as opposed to directly from EFI. These changes should also make it a lot saner to support cross-mode 32/64-bit EFI booting in the future. Getting these changes into 3.8 means we avoid presenting an inconsistent ABI to bootloaders. Other changes are display detection and fixing efivarfs." * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, efi: remove attribute check from setup_efi_pci x86, build: Dynamically find entry points in compressed startup code x86, efi: Fix PCI ROM handing in EFI boot stub, in 32-bit mode x86, efi: Fix 32-bit EFI handover protocol entry point x86, efi: Fix display detection in EFI boot stub x86, boot: Define the 2.12 bzImage boot protocol x86/boot: Fix minor fd leakage in tools/relocs.c x86, efi: Set runtime_version to the EFI spec revision x86, efi: fix 32-bit warnings in setup_efi_pci() efivarfs: Delete dentry from dcache in efivarfs_file_write() efivarfs: Never return ENOENT from firmware efi, x86: Pass a proper identity mapping in efi_call_phys_prelog efivarfs: Drop link count of the right inode
2013-01-30efi: Make 'efi_enabled' a function to query EFI facilitiesMatt Fleming3-4/+4
Originally 'efi_enabled' indicated whether a kernel was booted from EFI firmware. Over time its semantics have changed, and it now indicates whether or not we are booted on an EFI machine with bit-native firmware, e.g. 64-bit kernel with 64-bit firmware. The immediate motivation for this patch is the bug report at, https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 which details how running a platform driver on an EFI machine that is designed to run under BIOS can cause the machine to become bricked. Also, the following report, https://bugzilla.kernel.org/show_bug.cgi?id=47121 details how running said driver can also cause Machine Check Exceptions. Drivers need a new means of detecting whether they're running on an EFI machine, as sadly the expression, if (!efi_enabled) hasn't been a sufficient condition for quite some time. Users actually want to query 'efi_enabled' for different reasons - what they really want access to is the list of available EFI facilities. For instance, the x86 reboot code needs to know whether it can invoke the ResetSystem() function provided by the EFI runtime services, while the ACPI OSL code wants to know whether the EFI config tables were mapped successfully. There are also checks in some of the platform driver code to simply see if they're running on an EFI machine (which would make it a bad idea to do BIOS-y things). This patch is a prereq for the samsung-laptop fix patch. Cc: David Airlie <airlied@linux.ie> Cc: Corentin Chary <corentincj@iksaif.net> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Olof Johansson <olof@lixom.net> Cc: Peter Jones <pjones@redhat.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Steve Langasek <steve.langasek@canonical.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Konrad Rzeszutek Wilk <konrad@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-18efivarfs: Delete dentry from dcache in efivarfs_file_write()Matt Fleming1-0/+1
Unlike the unlink path that is called from the VFS layer, we need to call d_delete() ourselves when a variable is deleted in efivarfs_file_write(). Failure to do so means we can access a stale struct efivar_entry when reading/writing the file, which can result in the following oops, [ 59.978216] general protection fault: 0000 [#1] SMP [ 60.038660] CPU 9 [ 60.040501] Pid: 1001, comm: cat Not tainted 3.7.0-2.fc19.x86_64 #1 IBM System x3550 M3 -[7944I21]-/69Y4438 [ 60.050840] RIP: 0010:[<ffffffff810d5d1e>] [<ffffffff810d5d1e>] __lock_acquire+0x5e/0x1bb0 [ 60.059198] RSP: 0018:ffff880270595ce8 EFLAGS: 00010046 [ 60.064500] RAX: 0000000000000046 RBX: 0000000000000002 RCX: 0000000000000000 [ 60.071617] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 6b6b6b6b6b6b6b83 [ 60.078735] RBP: ffff880270595dd8 R08: 0000000000000002 R09: 0000000000000000 [ 60.085852] R10: 6b6b6b6b6b6b6b83 R11: 0000000000000000 R12: 0000000000000000 [ 60.092971] R13: ffff88027170cd20 R14: 0000000000000000 R15: 0000000000000000 [ 60.100091] FS: 00007fc0c8ff3740(0000) GS:ffff880277000000(0000) knlGS:0000000000000000 [ 60.108164] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 60.113899] CR2: 0000000001520000 CR3: 000000026d594000 CR4: 00000000000007e0 [ 60.121016] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 60.128135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 60.135254] Process cat (pid: 1001, threadinfo ffff880270594000, task ffff88027170cd20) [ 60.143239] Stack: [ 60.145251] ffff880270595cf8 ffffffff81021da3 ffff880270595d08 ffffffff81021e19 [ 60.152714] ffff880270595d38 ffffffff810acdb5 ffff880200000168 0000000000000086 [ 60.160175] ffff88027170d5e8 ffffffff810d25ed ffff880270595d58 ffffffff810ace7f [ 60.167638] Call Trace: [ 60.170088] [<ffffffff81021da3>] ? native_sched_clock+0x13/0x80 [ 60.176085] [<ffffffff81021e19>] ? sched_clock+0x9/0x10 [ 60.181389] [<ffffffff810acdb5>] ? sched_clock_cpu+0xc5/0x120 [ 60.187211] [<ffffffff810d25ed>] ? trace_hardirqs_off+0xd/0x10 [ 60.193121] [<ffffffff810ace7f>] ? local_clock+0x6f/0x80 [ 60.198513] [<ffffffff810d2f6f>] ? lock_release_holdtime.part.26+0xf/0x180 [ 60.205465] [<ffffffff810d7b57>] ? lock_release_non_nested+0x2e7/0x320 [ 60.212073] [<ffffffff815638bb>] ? efivarfs_file_write+0x5b/0x280 [ 60.218242] [<ffffffff810d7f41>] lock_acquire+0xa1/0x1f0 [ 60.223633] [<ffffffff81563971>] ? efivarfs_file_write+0x111/0x280 [ 60.229892] [<ffffffff8118b47c>] ? might_fault+0x5c/0xb0 [ 60.235287] [<ffffffff816f1bf6>] _raw_spin_lock+0x46/0x80 [ 60.240762] [<ffffffff81563971>] ? efivarfs_file_write+0x111/0x280 [ 60.247018] [<ffffffff81563971>] efivarfs_file_write+0x111/0x280 [ 60.253103] [<ffffffff811d307f>] vfs_write+0xaf/0x190 [ 60.258233] [<ffffffff811d33d5>] sys_write+0x55/0xa0 [ 60.263278] [<ffffffff816fbd19>] system_call_fastpath+0x16/0x1b [ 60.269271] Code: 41 0f 45 d8 4c 89 75 f0 4c 89 7d f8 85 c0 0f 84 09 01 00 00 8b 05 a3 f9 ff 00 49 89 fa 41 89 f6 41 89 d3 85 c0 0f 84 12 01 00 00 <49> 8b 02 ba 01 00 00 00 48 3d a0 07 14 82 0f 44 da 41 83 fe 01 [ 60.289431] RIP [<ffffffff810d5d1e>] __lock_acquire+0x5e/0x1bb0 [ 60.295444] RSP <ffff880270595ce8> [ 60.298928] ---[ end trace 1bbfd41a2cf6a0d8 ]--- Cc: Josh Boyer <jwboyer@redhat.com> Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Andy Whitcroft <apw@canonical.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-01-18efivarfs: Never return ENOENT from firmwareMatt Fleming1-1/+1
Files are created in efivarfs_create() before a corresponding variable is created in the firmware. This leads to users being able to read/write to the file without the variable existing in the firmware. Reading a non-existent variable currently returns -ENOENT, which is confusing because the file obviously *does* exist. Convert EFI_NOT_FOUND into -EIO which is the closest thing to "error while interacting with firmware", and should hopefully indicate to the caller that the variable is in some uninitialised state. Cc: Josh Boyer <jwboyer@redhat.com> Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Andy Whitcroft <apw@canonical.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-01-18efivarfs: Drop link count of the right inodeLingzhu Xiang1-1/+1
efivarfs_unlink() should drop the file's link count, not the directory's. Signed-off-by: Lingzhu Xiang <lxiang@redhat.com> Cc: Jeremy Kerr <jeremy.kerr@canonical.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 18:07:12 +0000