linux/drivers/firmware, branch v3.2.41

efi: be more paranoid about available space when creating variables

2013-03-20T15:03:28Z

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 Signed-off-by: Matt Fleming [bwh: Backported to 3.2: - Drop efivarfs changes and unused check_var_size() - Add error codes to include/linux/efi.h, added upstream by commit 5d9db883761a ('efi: Add support for a UEFI variable filesystem') - Add efi_status_to_err(), added upstream by commit 7253eaba7b17 ('efivarfs: Return an error if we fail to read a variable')] Signed-off-by: Ben Hutchings

efivars: Disable external interrupt while holding efivars->lock

2013-03-20T15:03:27Z

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 [bwh: Backported to 3.2: - Drop efivarfs changes - Adjust context - Drop change to efi_pstore_erase(), which is implemented using efi_pstore_write() here] Signed-off-by: Ben Hutchings

efi_pstore: Check remaining space with QueryVariableInfo() before writing data

2013-03-20T15:03:27Z

commit d80a361d779a9f19498943d1ca84243209cd5647 upstream. [Issue] As discussed in a thread below, Running out of space in EFI isn't a well-tested scenario. And we wouldn't expect all firmware to handle it gracefully. http://marc.info/?l=linux-kernel&m=134305325801789&w=2 On the other hand, current efi_pstore doesn't check a remaining space of storage at writing time. Therefore, efi_pstore may not work if it tries to write a large amount of data. [Patch Description] To avoid handling the situation above, this patch checks if there is a space enough to log with QueryVariableInfo() before writing data. Signed-off-by: Seiji Aguchi Acked-by: Mike Waychison Signed-off-by: Tony Luck Signed-off-by: Ben Hutchings

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

2013-03-20T15:03:24Z

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

drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists

2013-02-06T04:33:53Z

commit 9f9c9cbb60576a1518d0bf93fb8e499cffccf377 upstream. The right dmi version is in SMBIOS if it's zero in DMI region This issue was originally found from an oracle bug. One customer noticed system UUID doesn't match between dmidecode & uek2. - HP ProLiant BL460c G6 : # cat /sys/devices/virtual/dmi/id/product_uuid 00000000-0000-4C48-3031-4D5030333531 # dmidecode | grep -i uuid UUID: 00000000-0000-484C-3031-4D5030333531 From SMBIOS 2.6 on, spec use little-endian encoding for UUID other than network byte order. So we need to get dmi version to distinguish. If version is 0.0, the real version is taken from the SMBIOS version. This is part of original kernel comment in code. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Zhenzhong Duan Cc: Feng Jin Cc: Jean Delvare Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

drivers/firmware/dmi_scan.c: check dmi version when get system uuid

2013-02-06T04:33:53Z

commit f1d8e614d74b09531b9a85e812485340f3df7b1c upstream. As of version 2.6 of the SMBIOS specification, the first 3 fields of the UUID are supposed to be little-endian encoded. Also a minor fix to match variable meaning and mute checkpatch.pl [akpm@linux-foundation.org: tweak code comment] Signed-off-by: Zhenzhong Duan Cc: Feng Jin Cc: Jean Delvare Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

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

2013-02-06T04:33:50Z

commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream. 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 Signed-off-by: Matt Fleming Signed-off-by: H. Peter Anvin [bwh: Backported to 3.2: - Adjust context (a lot) - Add efi_is_native() function from commit 5189c2a7c776 ('x86: efi: Turn off efi_enabled after setup on mixed fw/kernel') - Make efi_init() bail out when booted non-native, as it would previously not be called in this case - Drop inapplicable changes to start_kernel()] Signed-off-by: Ben Hutchings

firmware: Add missing attributes to EFI variable attribute print out from sysfs

2012-10-17T02:48:20Z

commit 7083909023bbe29b3176e92d2d089def1aa7aa1e upstream. Some of the EFI variable attributes are missing from print out from /sys/firmware/efi/vars/*/attributes. This patch adds those in. It also updates code to use pre-defined constants for masking current value of attributes. Signed-off-by: Khalid Aziz Reviewed-by: Kees Cook Acked-by: Matthew Garrett Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings

dmi: Feed DMI table to /dev/random driver

2012-09-12T02:37:30Z

commit d114a33387472555188f142ed8e98acdb8181c6d upstream. Send the entire DMI (SMBIOS) table to the /dev/random driver to help seed its pools. Signed-off-by: Tony Luck Signed-off-by: Theodore Ts'o Signed-off-by: Ben Hutchings

pcdp: use early_ioremap/early_iounmap to access pcdp table

2012-08-09T23:25:00Z

commit 6c4088ac3a4d82779903433bcd5f048c58fb1aca upstream. efi_setup_pcdp_console() is called during boot to parse the HCDP/PCDP EFI system table and setup an early console for printk output. The routine uses ioremap/iounmap to setup access to the HCDP/PCDP table information. The call to ioremap is happening early in the boot process which leads to a panic on x86_64 systems: panic+0x01ca do_exit+0x043c oops_end+0x00a7 no_context+0x0119 __bad_area_nosemaphore+0x0138 bad_area_nosemaphore+0x000e do_page_fault+0x0321 page_fault+0x0020 reserve_memtype+0x02a1 __ioremap_caller+0x0123 ioremap_nocache+0x0012 efi_setup_pcdp_console+0x002b setup_arch+0x03a9 start_kernel+0x00d4 x86_64_start_reservations+0x012c x86_64_start_kernel+0x00fe This replaces the calls to ioremap/iounmap in efi_setup_pcdp_console() with calls to early_ioremap/early_iounmap which can be called during early boot. This patch was tested on an x86_64 prototype system which uses the HCDP/PCDP table for early console setup. Signed-off-by: Greg Pearson Acked-by: Khalid Aziz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings