user/sven/linux.git/drivers/firmware, branch v3.8.4

efi: be more paranoid about available space when creating variables

2013-03-14T18:26:37Z

commit 68d929862e29a8b52a7f2f2f86a0600423b093cd upstream. 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 Cc: Josh Boyer Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

efivars: Disable external interrupt while holding efivars->lock

2013-03-14T18:26:36Z

commit 81fa4e581d9283f7992a0d8c534bb141eb840a14 upstream. [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 Acked-by: Mike Waychison Acked-by: Matt Fleming Signed-off-by: Tony Luck Cc: Josh Boyer Signed-off-by: Greg Kroah-Hartman

efivarfs: return accurate error code in efivarfs_fill_super()

2013-03-14T18:26:25Z

commit feff5dc4f98330d8152b521acc2e18c16712e6c8 upstream. 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 Reported-by: Lingzhu Xiang Cc: Josh Boyer Cc: Jeremy Kerr Cc: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

efivars: efivarfs_valid_name() should handle pstore syntax

2013-03-14T18:26:25Z

commit 123abd76edf56c02a76b46d3d673897177ef067b upstream. 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-. 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 Tested-by: Joseph Yasi Reported-by: Lingzhu Xiang Cc: Josh Boyer Cc: Jeremy Kerr Cc: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

dmi_scan: fix missing check for _DMI_ signature in smbios_present()

2013-03-14T18:26:24Z

commit a40e7cf8f06b4e322ba902e4e9f6a6b0c2daa907 upstream. 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 Reported-by: Tim McGrath Tested-by: Tim Mcgrath Cc: Zhenzhong Duan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

efivarfs: guid part of filenames are case-insensitive

2013-03-03T22:03:40Z

commit da27a24383b2b10bf6ebd0db29b325548aafecb4 upstream. 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 Cc: Matthew Garrett Cc: Jeremy Kerr Cc: Al Viro Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

efivarfs: Validate filenames much more aggressively

2013-03-03T22:03:40Z

commit 47f531e8ba3bc3901a0c493f4252826c41dea1a1 upstream. 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 Cc: Matthew Garrett Cc: Jeremy Kerr Cc: Al Viro Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-01-31T06:10:36Z

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

efi: Make 'efi_enabled' a function to query EFI facilities

2013-01-30T19:51:59Z

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 Cc: Corentin Chary Cc: Matthew Garrett Cc: Dave Jiang Cc: Olof Johansson Cc: Peter Jones Cc: Colin Ian King Cc: Steve Langasek Cc: Tony Luck Cc: Konrad Rzeszutek Wilk Cc: Rafael J. Wysocki Cc: Signed-off-by: Matt Fleming Signed-off-by: H. Peter Anvin

efivarfs: Delete dentry from dcache in efivarfs_file_write()

2013-01-18T09:43:44Z

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:[] [] __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] [] ? native_sched_clock+0x13/0x80 [ 60.176085] [] ? sched_clock+0x9/0x10 [ 60.181389] [] ? sched_clock_cpu+0xc5/0x120 [ 60.187211] [] ? trace_hardirqs_off+0xd/0x10 [ 60.193121] [] ? local_clock+0x6f/0x80 [ 60.198513] [] ? lock_release_holdtime.part.26+0xf/0x180 [ 60.205465] [] ? lock_release_non_nested+0x2e7/0x320 [ 60.212073] [] ? efivarfs_file_write+0x5b/0x280 [ 60.218242] [] lock_acquire+0xa1/0x1f0 [ 60.223633] [] ? efivarfs_file_write+0x111/0x280 [ 60.229892] [] ? might_fault+0x5c/0xb0 [ 60.235287] [] _raw_spin_lock+0x46/0x80 [ 60.240762] [] ? efivarfs_file_write+0x111/0x280 [ 60.247018] [] efivarfs_file_write+0x111/0x280 [ 60.253103] [] vfs_write+0xaf/0x190 [ 60.258233] [] sys_write+0x55/0xa0 [ 60.263278] [] 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 [] __lock_acquire+0x5e/0x1bb0 [ 60.295444] RSP [ 60.298928] ---[ end trace 1bbfd41a2cf6a0d8 ]--- Cc: Josh Boyer Acked-by: Jeremy Kerr Cc: Lee, Chun-Yi Cc: Andy Whitcroft Reported-by: Lingzhu Xiang Signed-off-by: Matt Fleming