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2015-07-30efi: Check for NULL efi kernel parametersRicardo Neri1-0/+5
Even though it is documented how to specifiy efi parameters, it is possible to cause a kernel panic due to a dereference of a NULL pointer when parsing such parameters if "efi" alone is given: PANIC: early exception 0e rip 10:ffffffff812fb361 error 0 cr2 0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.2.0-rc1+ #450 [ 0.000000] ffffffff81fe20a9 ffffffff81e03d50 ffffffff8184bb0f 00000000000003f8 [ 0.000000] 0000000000000000 ffffffff81e03e08 ffffffff81f371a1 64656c62616e6520 [ 0.000000] 0000000000000069 000000000000005f 0000000000000000 0000000000000000 [ 0.000000] Call Trace: [ 0.000000] [<ffffffff8184bb0f>] dump_stack+0x45/0x57 [ 0.000000] [<ffffffff81f371a1>] early_idt_handler_common+0x81/0xae [ 0.000000] [<ffffffff812fb361>] ? parse_option_str+0x11/0x90 [ 0.000000] [<ffffffff81f4dd69>] arch_parse_efi_cmdline+0x15/0x42 [ 0.000000] [<ffffffff81f376e1>] do_early_param+0x50/0x8a [ 0.000000] [<ffffffff8106b1b3>] parse_args+0x1e3/0x400 [ 0.000000] [<ffffffff81f37a43>] parse_early_options+0x24/0x28 [ 0.000000] [<ffffffff81f37691>] ? loglevel+0x31/0x31 [ 0.000000] [<ffffffff81f37a78>] parse_early_param+0x31/0x3d [ 0.000000] [<ffffffff81f3ae98>] setup_arch+0x2de/0xc08 [ 0.000000] [<ffffffff8109629a>] ? vprintk_default+0x1a/0x20 [ 0.000000] [<ffffffff81f37b20>] start_kernel+0x90/0x423 [ 0.000000] [<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c [ 0.000000] [<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef [ 0.000000] RIP 0xffffffff81ba2efc This panic is not reproducible with "efi=" as this will result in a non-NULL zero-length string. Thus, verify that the pointer to the parameter string is not NULL. This is consistent with other parameter-parsing functions which check for NULL pointers. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-07-21Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgentIngo Molnar1-3/+12
Pull an EFI fix from Matt Fleming: - Fix a bug in the Common Platform Error Record (CPER) driver that caused old UEFI spec (< 2.3) versions of the memory error record structure to be declared invalid. (Tony Luck) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-15efi: Handle memory error structures produced based on old versions of standardLuck, Tony1-3/+12
The memory error record structure includes as its first field a bitmask of which subsequent fields are valid. The allows new fields to be added to the structure while keeping compatibility with older software that parses these records. This mechanism was used between versions 2.2 and 2.3 to add four new fields, growing the size of the structure from 73 bytes to 80. But Linux just added all the new fields so this test: if (gdata->error_data_length >= sizeof(*mem_err)) cper_print_mem(newpfx, mem_err); else goto err_section_too_small; now make Linux complain about old format records being too short. Add a definition for the old format of the structure and use that for the minimum size check. Pass the actual size to cper_print_mem() so it can sanity check the validation_bits field to ensure that if a BIOS using the old format sets bits as if it were new, we won't access fields beyond the end of the structure. Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-07-03Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespaceLinus Torvalds1-4/+2
Pull user namespace updates from Eric Biederman: "Long ago and far away when user namespaces where young it was realized that allowing fresh mounts of proc and sysfs with only user namespace permissions could violate the basic rule that only root gets to decide if proc or sysfs should be mounted at all. Some hacks were put in place to reduce the worst of the damage could be done, and the common sense rule was adopted that fresh mounts of proc and sysfs should allow no more than bind mounts of proc and sysfs. Unfortunately that rule has not been fully enforced. There are two kinds of gaps in that enforcement. Only filesystems mounted on empty directories of proc and sysfs should be ignored but the test for empty directories was insufficient. So in my tree directories on proc, sysctl and sysfs that will always be empty are created specially. Every other technique is imperfect as an ordinary directory can have entries added even after a readdir returns and shows that the directory is empty. Special creation of directories for mount points makes the code in the kernel a smidge clearer about it's purpose. I asked container developers from the various container projects to help test this and no holes were found in the set of mount points on proc and sysfs that are created specially. This set of changes also starts enforcing the mount flags of fresh mounts of proc and sysfs are consistent with the existing mount of proc and sysfs. I expected this to be the boring part of the work but unfortunately unprivileged userspace winds up mounting fresh copies of proc and sysfs with noexec and nosuid clear when root set those flags on the previous mount of proc and sysfs. So for now only the atime, read-only and nodev attributes which userspace happens to keep consistent are enforced. Dealing with the noexec and nosuid attributes remains for another time. This set of changes also addresses an issue with how open file descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of /proc/<pid>/fd has been triggering a WARN_ON that has not been meaningful since it was added (as all of the code in the kernel was converted) and is not now actively wrong. There is also a short list of issues that have not been fixed yet that I will mention briefly. It is possible to rename a directory from below to above a bind mount. At which point any directory pointers below the renamed directory can be walked up to the root directory of the filesystem. With user namespaces enabled a bind mount of the bind mount can be created allowing the user to pick a directory whose children they can rename to outside of the bind mount. This is challenging to fix and doubly so because all obvious solutions must touch code that is in the performance part of pathname resolution. As mentioned above there is also a question of how to ensure that developers by accident or with purpose do not introduce exectuable files on sysfs and proc and in doing so introduce security regressions in the current userspace that will not be immediately obvious and as such are likely to require breaking userspace in painful ways once they are recognized" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: vfs: Remove incorrect debugging WARN in prepend_path mnt: Update fs_fully_visible to test for permanently empty directories sysfs: Create mountpoints with sysfs_create_mount_point sysfs: Add support for permanently empty directories to serve as mount points. kernfs: Add support for always empty directories. proc: Allow creating permanently empty directories that serve as mount points sysctl: Allow creating permanently empty directories that serve as mountpoints. fs: Add helper functions for permanently empty directories. vfs: Ignore unlocked mounts in fs_fully_visible mnt: Modify fs_fully_visible to deal with locked ro nodev and atime mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-01Merge tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linuxLinus Torvalds1-2/+0
Pull devicetree updates from Grant Likely: "A whole lot of bug fixes. Nothing stands out here except the ability to enable CONFIG_OF on every architecture, and an import of a newer version of dtc" * tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux: (22 commits) of/irq: Rename "intc_desc" to "of_intc_desc" to fix OF on sh of/irq: Fix pSeries boot failure Documentation: DT: Fix a typo in the filename "lantiq,<chip>-pinumx.txt" of: define of_find_node_by_phandle for !CONFIG_OF of/address: use atomic allocation in pci_register_io_range() of: Add vendor prefix for Zodiac Inflight Innovations dt/fdt: add empty versions of early_init_dt_*_memory_arch of: clean-up unnecessary libfdt include paths of: make unittest select OF_EARLY_FLATTREE instead of depend on it of: make CONFIG_OF user selectable MIPS: prepare for user enabling of CONFIG_OF of/fdt: fix argument name and add comments of unflatten_dt_node() of: return NUMA_NO_NODE from fallback of_node_to_nid() tps6507x.txt: Remove executable permission of/overlay: Grammar s/an negative/a negative/ of/fdt: Make fdt blob input parameters of unflatten functions const of: add helper function to retrive match data of: Grammar s/property exist/property exists/ of: Move OF flags to be visible even when !CONFIG_OF scripts/dtc: Update to upstream version 9d3649bd3be245c9 ...
2015-07-01sysfs: Create mountpoints with sysfs_create_mount_pointEric W. Biederman1-4/+2
This allows for better documentation in the code and it allows for a simpler and fully correct version of fs_fully_visible to be written. The mount points converted and their filesystems are: /sys/hypervisor/s390/ s390_hypfs /sys/kernel/config/ configfs /sys/kernel/debug/ debugfs /sys/firmware/efi/efivars/ efivarfs /sys/fs/fuse/connections/ fusectl /sys/fs/pstore/ pstore /sys/kernel/tracing/ tracefs /sys/fs/cgroup/ cgroup /sys/kernel/security/ securityfs /sys/fs/selinux/ selinuxfs /sys/fs/smackfs/ smackfs Cc: stable@vger.kernel.org Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-06-30Merge remote-tracking branch 'robh/for-next' into devicetree/nextGrant Likely1-2/+0
2015-06-11Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efiIngo Molnar2-1/+7
Pull EFI build fix from Matt Fleming: - Fix ESRT build breakage on ia64 reported by Guenter Roeck. (Peter Jones) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-08efi: Work around ia64 build problem with ESRT driverPeter Jones2-1/+7
So, I'm told this problem exists in the world: > Subject: Build error in -next due to 'efi: Add esrt support' > > Building ia64:defconfig ... failed > -------------- > Error log: > > drivers/firmware/efi/esrt.c:28:31: fatal error: asm/early_ioremap.h: No such file or directory > I'm not really sure how it's okay that we have things in asm-generic on some platforms but not others - is having it the same everywhere not the whole point of asm-generic? That said, ia64 doesn't have early_ioremap.h . So instead, since it's difficult to imagine new IA64 machines with UEFI 2.5, just don't build this code there. To me this looks like a workaround - doing something like: generic-y += early_ioremap.h in arch/ia64/include/asm/Kbuild would appear to be more correct, but ia64 has its own early_memremap() decl in arch/ia64/include/asm/io.h , and it's a macro. So adding the above /and/ requiring that asm/io.h be included /after/ asm/early_ioremap.h in all cases would fix it, but that's pretty ugly as well. Since I'm not going to spend the rest of my life rectifying ia64 headers vs "generic" headers that aren't generic, it's much simpler to just not build there. Note that I've only actually tried to build this patch on x86_64, but esrt.o still gets built there, and that would seem to demonstrate that the conditional building is working correctly at all the places the code built before. I no longer have any ia64 machines handy to test that the exclusion actually works there. Signed-off-by: Peter Jones <pjones@redhat.com> Acked-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> (Compile-)Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-06-04of: clean-up unnecessary libfdt include pathsRob Herring1-2/+0
With the libfdt include fixups to use "" instead of <> in the latest dtc import in commit 4760597 (scripts/dtc: Update to upstream version 9d3649bd3be245c9), it is no longer necessary to add explicit include paths to use libfdt. Remove these across the kernel. Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Grant Likely <grant.likely@linaro.org> Cc: linux-mips@linux-mips.org Cc: linuxppc-dev@lists.ozlabs.org
2015-06-02Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efiIngo Molnar4-9/+566
Pull EFI changes from Matt Fleming: - Use idiomatic negative error values in efivar_create_sysfs_entry() instead of returning '1' to indicate error. (Dan Carpenter) - Implement new support to expose the EFI System Resource Tables in sysfs, which provides information for performing firmware updates. (Peter Jones) - Documentation cleanup in the EFI handover protocol section which falsely claimed that 'cmdline_size' needed to be filled out by the boot loader. (Alex Smith) - Align the order of SMBIOS tables in /sys/firmware/efi/systab to match the way that we do things for ACPI and add documentation to Documentation/ABI. (Jean Delvare) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-06Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgentIngo Molnar1-3/+3
Pull EFI fixes from Matt Fleming: * Avoid garbage names in efivarfs due to buggy firmware by zeroing EFI variable name. (Ross Lagerwall) * Stop erroneously dropping upper 32 bits of boot command line pointer in EFI boot stub and stash them in ext_cmd_line_ptr. (Roy Franz) * Fix double-free bug in error handling code path of EFI runtime map code. (Dan Carpenter) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-05efi: dmi: List SMBIOS3 table before SMBIOS tableJean Delvare1-2/+7
The SMBIOS3 table should appear before the SMBIOS table in /sys/firmware/efi/systab. This allows user-space utilities which support both to pick the SMBIOS3 table with a single pass on systems where both are implemented. The SMBIOS3 entry point is more capable than the SMBIOS entry point so it should be preferred. This follows the same logic as the ACPI20 table being listed before the ACPI table. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-05-05efi: Fix error handling in add_sysfs_runtime_map_entry()Dan Carpenter1-3/+3
I spotted two (difficult to hit) bugs while reviewing this. 1) There is a double free bug because we unregister "map_kset" in add_sysfs_runtime_map_entry() and also efi_runtime_map_init(). 2) If we fail to allocate "entry" then we should return ERR_PTR(-ENOMEM) instead of NULL. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Dave Young <dyoung@redhat.com> Cc: Guangyu Sun <guangyu.sun@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-04-30efi/esrt: Fix some compiler warningsPeter Jones1-11/+18
Apparently I missed some compiler warnings on 32-bit platforms, where phys_addr_t isn't the same size as void * and I casted it to make printk work. Obviously I should have thought "I'm printing some random type, instead of typecasting I should check Documentation/printk-formats.txt and see how to do it." o/~ The More You Know ☆彡 o/~ This patch also fixes one other warning about an uninitialized variable some compiler versions seem to see. You can't actually hit the code path where it would be uninitialized, because there's a prior test that would error out, but gcc hasn't figured that out. Anyway, it now has a test and returns the error at both places. Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-04-30efi: Add esrt supportPeter Jones3-2/+546
Add sysfs files for the EFI System Resource Table (ESRT) under /sys/firmware/efi/esrt and for each EFI System Resource Entry under entries/ as a subdir. The EFI System Resource Table (ESRT) provides a read-only catalog of system components for which the system accepts firmware upgrades via UEFI's "Capsule Update" feature. This module allows userland utilities to evaluate what firmware updates can be applied to this system, and potentially arrange for those updates to occur. The ESRT is described as part of the UEFI specification, in version 2.5 which should be available from http://uefi.org/specifications in early 2015. If you're a member of the UEFI Forum, information about its addition to the standard is available as UEFI Mantis 1090. For some hardware platforms, additional restrictions may be found at http://msdn.microsoft.com/en-us/library/windows/hardware/jj128256.aspx , and additional documentation may be found at http://download.microsoft.com/download/5/F/5/5F5D16CD-2530-4289-8019-94C6A20BED3C/windows-uefi-firmware-update-platform.docx . Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-04-30efi: efivar_create_sysfs_entry() should return negative error codesDan Carpenter1-5/+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>
2015-04-01efi/libstub: Retrieve FDT size when loaded from UEFI config tableArd Biesheuvel3-6/+10
When allocating memory for the copy of the FDT that the stub modifies and passes to the kernel, it uses the current size as an estimate of how much memory to allocate, and increases it page by page if it turns out to be too small. However, when loading the FDT from a UEFI configuration table, the estimated size is left at its default value of zero, and the allocation loop runs starting from zero all the way up to the allocation size that finally fits the updated FDT. Instead, retrieve the size of the FDT from the FDT header when loading it from the UEFI config table. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Roy Franz <roy.franz@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-03-02Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgentIngo Molnar1-4/+4
Pull EFI fixes from Matt Fleming: " - Fix regression in DMI sysfs code for handling "End of Table" entry and a type bug that could lead to integer overflow. (Ivan Khoronzhuk) - Fix boundary checking in efi_high_alloc() which can lead to memory corruption in the EFI boot stubs. (Yinghai Lu)" Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-24efi/libstub: Fix boundary checking in efi_high_alloc()Yinghai Lu1-4/+4
While adding support loading kernel and initrd above 4G to grub2 in legacy mode, I was referring to efi_high_alloc(). That will allocate buffer for kernel and then initrd, and initrd will use kernel buffer start as limit. During testing found two buffers will be overlapped when initrd size is very big like 400M. It turns out efi_high_alloc() boundary checking is not right. end - size will be the new start, and should not compare new start with max, we need to make sure end is smaller than max. [ Basically, with the current efi_high_alloc() code it's possible to allocate memory above 'max', because efi_high_alloc() doesn't check that the tail of the allocation is below 'max'. If you have an EFI memory map with a single entry that looks like so, [0xc0000000-0xc0004000] And want to allocate 0x3000 bytes below 0xc0003000 the current code will allocate [0xc0001000-0xc0004000], not [0xc0000000-0xc0003000] like you would expect. - Matt ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-02-21Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-10/+6
Pull misc x86 fixes from Ingo Molnar: "This contains: - EFI fixes - a boot printout fix - ASLR/kASLR fixes - intel microcode driver fixes - other misc fixes Most of the linecount comes from an EFI revert" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/ASLR: Avoid PAGE_SIZE redefinition for UML subarch x86/microcode/intel: Handle truncated microcode images more robustly x86/microcode/intel: Guard against stack overflow in the loader x86, mm/ASLR: Fix stack randomization on 64-bit systems x86/mm/init: Fix incorrect page size in init_memory_mapping() printks x86/mm/ASLR: Propagate base load address calculation Documentation/x86: Fix path in zero-page.txt x86/apic: Fix the devicetree build in certain configs Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes" x86/efi: Avoid triple faults during EFI mixed mode calls
2015-02-18Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes"Matt Fleming1-10/+6
This reverts commit d1a8d66b9177105e898e73716f97eb61842c457a. Ard reported a boot failure when running UEFI under Qemu and Xen and experimenting with various Tianocore build options, "As it turns out, when allocating room for the UEFI memory map using UEFI's AllocatePool (), it may result in two new memory map entries being created, for instance, when using Tianocore's preallocated region feature. For example, the following region 0x00005ead5000-0x00005ebfffff [Conventional Memory| | | | | |WB|WT|WC|UC] may be split like this 0x00005ead5000-0x00005eae2fff [Conventional Memory| | | | | |WB|WT|WC|UC] 0x00005eae3000-0x00005eae4fff [Loader Data | | | | | |WB|WT|WC|UC] 0x00005eae5000-0x00005ebfffff [Conventional Memory| | | | | |WB|WT|WC|UC] if the preallocated Loader Data region was chosen to be right in the middle of the original free space. After patch d1a8d66b9177 ("efi/libstub: Call get_memory_map() to obtain map and desc sizes"), this is not being dealt with correctly anymore, as the existing logic to allocate room for a single additional entry has become insufficient." Mark requested to reinstate the old loop we had before commit d1a8d66b9177, which grows the memory map buffer until it's big enough to hold the EFI memory map. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-02-13x86_64: kasan: add interceptors for memset/memmove/memcpy functionsAndrey Ryabinin1-0/+4
Recently instrumentation of builtin functions calls was removed from GCC 5.0. To check the memory accessed by such functions, userspace asan always uses interceptors for them. So now we should do this as well. This patch declares memset/memmove/memcpy as weak symbols. In mm/kasan/kasan.c we have our own implementation of those functions which checks memory before accessing it. Default memset/memmove/memcpy now now always have aliases with '__' prefix. For files that built without kasan instrumentation (e.g. mm/slub.c) original mem* replaced (via #define) with prefixed variants, cause we don't want to check memory accesses there. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13kasan: add kernel address sanitizer infrastructureAndrey Ryabinin1-0/+1
Kernel Address sanitizer (KASan) is a dynamic memory error detector. It provides fast and comprehensive solution for finding use-after-free and out-of-bounds bugs. KASAN uses compile-time instrumentation for checking every memory access, therefore GCC > v4.9.2 required. v4.9.2 almost works, but has issues with putting symbol aliases into the wrong section, which breaks kasan instrumentation of globals. This patch only adds infrastructure for kernel address sanitizer. It's not available for use yet. The idea and some code was borrowed from [1]. Basic idea: The main idea of KASAN is to use shadow memory to record whether each byte of memory is safe to access or not, and use compiler's instrumentation to check the shadow memory on each memory access. Address sanitizer uses 1/8 of the memory addressable in kernel for shadow memory and uses direct mapping with a scale and offset to translate a memory address to its corresponding shadow address. Here is function to translate address to corresponding shadow address: unsigned long kasan_mem_to_shadow(unsigned long addr) { return (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET; } where KASAN_SHADOW_SCALE_SHIFT = 3. So for every 8 bytes there is one corresponding byte of shadow memory. The following encoding used for each shadow byte: 0 means that all 8 bytes of the corresponding memory region are valid for access; k (1 <= k <= 7) means that the first k bytes are valid for access, and other (8 - k) bytes are not; Any negative value indicates that the entire 8-bytes are inaccessible. Different negative values used to distinguish between different kinds of inaccessible memory (redzones, freed memory) (see mm/kasan/kasan.h). To be able to detect accesses to bad memory we need a special compiler. Such compiler inserts a specific function calls (__asan_load*(addr), __asan_store*(addr)) before each memory access of size 1, 2, 4, 8 or 16. These functions check whether memory region is valid to access or not by checking corresponding shadow memory. If access is not valid an error printed. Historical background of the address sanitizer from Dmitry Vyukov: "We've developed the set of tools, AddressSanitizer (Asan), ThreadSanitizer and MemorySanitizer, for user space. We actively use them for testing inside of Google (continuous testing, fuzzing, running prod services). To date the tools have found more than 10'000 scary bugs in Chromium, Google internal codebase and various open-source projects (Firefox, OpenSSL, gcc, clang, ffmpeg, MySQL and lots of others): [2] [3] [4]. The tools are part of both gcc and clang compilers. We have not yet done massive testing under the Kernel AddressSanitizer (it's kind of chicken and egg problem, you need it to be upstream to start applying it extensively). To date it has found about 50 bugs. Bugs that we've found in upstream kernel are listed in [5]. We've also found ~20 bugs in out internal version of the kernel. Also people from Samsung and Oracle have found some. [...] As others noted, the main feature of AddressSanitizer is its performance due to inline compiler instrumentation and simple linear shadow memory. User-space Asan has ~2x slowdown on computational programs and ~2x memory consumption increase. Taking into account that kernel usually consumes only small fraction of CPU and memory when running real user-space programs, I would expect that kernel Asan will have ~10-30% slowdown and similar memory consumption increase (when we finish all tuning). I agree that Asan can well replace kmemcheck. We have plans to start working on Kernel MemorySanitizer that finds uses of unitialized memory. Asan+Msan will provide feature-parity with kmemcheck. As others noted, Asan will unlikely replace debug slab and pagealloc that can be enabled at runtime. Asan uses compiler instrumentation, so even if it is disabled, it still incurs visible overheads. Asan technology is easily portable to other architectures. Compiler instrumentation is fully portable. Runtime has some arch-dependent parts like shadow mapping and atomic operation interception. They are relatively easy to port." Comparison with other debugging features: ======================================== KMEMCHECK: - KASan can do almost everything that kmemcheck can. KASan uses compile-time instrumentation, which makes it significantly faster than kmemcheck. The only advantage of kmemcheck over KASan is detection of uninitialized memory reads. Some brief performance testing showed that kasan could be x500-x600 times faster than kmemcheck: $ netperf -l 30 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost (127.0.0.1) port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec no debug: 87380 16384 16384 30.00 41624.72 kasan inline: 87380 16384 16384 30.00 12870.54 kasan outline: 87380 16384 16384 30.00 10586.39 kmemcheck: 87380 16384 16384 30.03 20.23 - Also kmemcheck couldn't work on several CPUs. It always sets number of CPUs to 1. KASan doesn't have such limitation. DEBUG_PAGEALLOC: - KASan is slower than DEBUG_PAGEALLOC, but KASan works on sub-page granularity level, so it able to find more bugs. SLUB_DEBUG (poisoning, redzones): - SLUB_DEBUG has lower overhead than KASan. - SLUB_DEBUG in most cases are not able to detect bad reads, KASan able to detect both reads and writes. - In some cases (e.g. redzone overwritten) SLUB_DEBUG detect bugs only on allocation/freeing of object. KASan catch bugs right before it will happen, so we always know exact place of first bad read/write. [1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel [2] https://code.google.com/p/address-sanitizer/wiki/FoundBugs [3] https://code.google.com/p/thread-sanitizer/wiki/FoundBugs [4] https://code.google.com/p/memory-sanitizer/wiki/FoundBugs [5] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel#Trophies Based on work by Andrey Konovalov. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Acked-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds5-35/+171
Pull arm64 updates from Catalin Marinas: "arm64 updates for 3.20: - reimplementation of the virtual remapping of UEFI Runtime Services in a way that is stable across kexec - emulation of the "setend" instruction for 32-bit tasks (user endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set accordingly) - compat_sys_call_table implemented in C (from asm) and made it a constant array together with sys_call_table - export CPU cache information via /sys (like other architectures) - DMA API implementation clean-up in preparation for IOMMU support - macros clean-up for KVM - dropped some unnecessary cache+tlb maintenance - CONFIG_ARM64_CPU_SUSPEND clean-up - defconfig update (CPU_IDLE) The EFI changes going via the arm64 tree have been acked by Matt Fleming. There is also a patch adding sys_*stat64 prototypes to include/linux/syscalls.h, acked by Andrew Morton" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (47 commits) arm64: compat: Remove incorrect comment in compat_siginfo arm64: Fix section mismatch on alloc_init_p[mu]d() arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros arm64: mm: use *_sect to check for section maps arm64: drop unnecessary cache+tlb maintenance arm64:mm: free the useless initial page table arm64: Enable CPU_IDLE in defconfig arm64: kernel: remove ARM64_CPU_SUSPEND config option arm64: make sys_call_table const arm64: Remove asm/syscalls.h arm64: Implement the compat_sys_call_table in C syscalls: Declare sys_*stat64 prototypes if __ARCH_WANT_(COMPAT_)STAT64 compat: Declare compat_sys_sigpending and compat_sys_sigprocmask prototypes arm64: uapi: expose our struct ucontext to the uapi headers smp, ARM64: Kill SMP single function call interrupt arm64: Emulate SETEND for AArch32 tasks arm64: Consolidate hotplug notifier for instruction emulation arm64: Track system support for mixed endian EL0 arm64: implement generic IOMMU configuration arm64: Combine coherent and non-coherent swiotlb dma_ops ...
2015-01-29Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efiIngo Molnar7-24/+45
Pull EFI updates from Matt Fleming: " - Move efivarfs from the misc filesystem section to pseudo filesystem, since that's a more logical and accurate place - Leif Lindholm - Update efibootmgr URL in Kconfig help - Peter Jones - Improve accuracy of EFI guid function names - Borislav Petkov - Expose firmware platform size in sysfs for the benefit of EFI boot loader installers and other utilities - Steve McIntyre - Cleanup __init annotations for arm64/efi code - Ard Biesheuvel - Mark the UIE as unsupported for rtc-efi - Ard Biesheuvel - Fix memory leak in error code path of runtime map code - Dan Carpenter - Improve robustness of get_memory_map() by removing assumptions on the size of efi_memory_desc_t (which could change in future spec versions) and querying the firmware instead of guessing about the memmap size - Ard Biesheuvel - Remove superfluous guid unparse calls - Ivan Khoronzhuk - Delete unnecessary chosen@0 DT node FDT code since was duplicated from code in drivers/of and is entirely unnecessary - Leif Lindholm There's nothing super scary, mainly cleanups, and a merge from Ricardo who kindly picked up some patches from the linux-efi mailing list while I was out on annual leave in December. Perhaps the biggest risk is the get_memory_map() change from Ard, which changes the way that both the arm64 and x86 EFI boot stub build the early memory map. It would be good to have it bake in linux-next for a while. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-20efi: Don't look for chosen@0 node on DT platformsLeif Lindholm1-2/+1
Due to some scary special case handling noticed in drivers/of, various bits of the ARM* EFI support patches did duplicate looking for @0 variants of various nodes. Unless on an ancient PPC system, these are not in fact required. Most instances have become refactored out along the way, this removes the last one. Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-20firmware: efi: Remove unneeded guid unparseIvan Khoronzhuk1-5/+0
There is no reason to translate guid number to string here. So remove it in order to not do unneeded work. Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-20efi/libstub: Call get_memory_map() to obtain map and desc sizesArd Biesheuvel1-6/+10
This fixes two minor issues in the implementation of get_memory_map(): - Currently, it assumes that sizeof(efi_memory_desc_t) == desc_size, which is usually true, but not mandated by the spec. (This was added intentionally to allow future additions to the definition of efi_memory_desc_t). The way the loop is implemented currently, the added slack space may be insufficient if desc_size is larger, which in some corner cases could result in the loop never terminating. - It allocates 32 efi_memory_desc_t entries first (again, using the size of the struct instead of desc_size), and frees and reallocates if it turns out to be insufficient. Few implementations of UEFI have such small memory maps, which results in a unnecessary allocate/free pair on each invocation. Fix this by calling the get_memory_map() boot service first with a '0' input value for map size to retrieve the map size and desc size from the firmware and only then perform the allocation, using desc_size rather than sizeof(efi_memory_desc_t). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-20efi: Small leak on error in runtime map codeDan Carpenter1-1/+1
The "> 0" here should ">= 0" so we free map_entries[0]. Fixes: 926172d46038 ('efi: Export EFI runtime memory mapping to sysfs') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Dave Young <dyoung@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-15arm64/efi: efistub: Apply __init annotationArd Biesheuvel3-5/+19
This ensures all stub component are freed when the kernel proper is done booting, by prefixing the names of all ELF sections that have the SHF_ALLOC attribute with ".init". This approach ensures that even implicitly emitted allocated data (like initializer values and string literals) are covered. At the same time, remove some __init annotations in the stub that have now become redundant, and add the __init annotation to handle_kernel_image which will now trigger a section mismatch warning without it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-12arm64/efi: move SetVirtualAddressMap() to UEFI stubArd Biesheuvel3-3/+122
In order to support kexec, the kernel needs to be able to deal with the state of the UEFI firmware after SetVirtualAddressMap() has been called. To avoid having separate code paths for non-kexec and kexec, let's move the call to SetVirtualAddressMap() to the stub: this will guarantee us that it will only be called once (since the stub is not executed during kexec), and ensures that the UEFI state is identical between kexec and normal boot. This implies that the layout of the virtual mapping needs to be created by the stub as well. All regions are rounded up to a naturally aligned multiple of 64 KB (for compatibility with 64k pages kernels) and recorded in the UEFI memory map. The kernel proper reads those values and installs the mappings in a dedicated set of page tables that are swapped in during UEFI Runtime Services calls. Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12efi: Expose underlying UEFI firmware platform size to userlandSteve McIntyre1-0/+9
In some cases (e.g. Intel Bay Trail machines), the kernel will happily run in 64-bit even if the underlying UEFI firmware platform is 32-bit. That's great, but it's difficult for userland utilities like grub-install to do the right thing in such a situation. The kernel already knows about the size of the firmware via efi_enabled(EFI_64BIT). Add an extra sysfs interface /sys/firmware/efi/fw_platform_size to expose that information to userland for low-level utilities to use. Signed-off-by: Steve McIntyre <steve@einval.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-12efi: efistub: allow allocation alignment larger than EFI_PAGE_SIZEArd Biesheuvel1-8/+17
On systems with 64 KB pages, it is preferable for UEFI memory map entries to be 64 KB aligned multiples of 64 KB, because it relieves us of having to deal with the residues. So, if EFI_ALLOC_ALIGN is #define'd by the platform, use it to round up all memory allocations made. Acked-by: Matt Fleming <matt.fleming@intel.com> Acked-by: Borislav Petkov <bp@suse.de> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12efi: split off remapping code from efi_config_init()Ard Biesheuvel1-24/+32
Split of the remapping code from efi_config_init() so that the caller can perform its own remapping. This is necessary to correctly handle virtually remapped UEFI memory regions under kexec, as efi.systab will have been updated to a virtual address. Acked-by: Matt Fleming <matt.fleming@intel.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-07efi: Rename efi_guid_unparse to efi_guid_to_strBorislav Petkov2-5/+5
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>
2015-01-07efi: Update the URLs for efibootmgrPeter Jones1-2/+2
Matt Domsch changed the dell page to point to the new upstream quite some time ago; kernel should reflect that here as well. Cc: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
2014-12-10Merge tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds1-1/+1
Pull tracing updates from Steven Rostedt: "There was a lot of clean ups and minor fixes. One of those clean ups was to the trace_seq code. It also removed the return values to the trace_seq_*() functions and use trace_seq_has_overflowed() to see if the buffer filled up or not. This is similar to work being done to the seq_file code as well in another tree. Some of the other goodies include: - Added some "!" (NOT) logic to the tracing filter. - Fixed the frame pointer logic to the x86_64 mcount trampolines - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems. That is, the ftrace trampoline can be dynamically allocated and be called directly by functions that only have a single hook to them" * tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits) tracing: Truncated output is better than nothing tracing: Add additional marks to signal very large time deltas Documentation: describe trace_buf_size parameter more accurately tracing: Allow NOT to filter AND and OR clauses tracing: Add NOT to filtering logic ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter ftrace/x86: Get rid of ftrace_caller_setup ftrace/x86: Have save_mcount_regs macro also save stack frames if needed ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs ftrace/x86: Simplify save_mcount_regs on getting RIP ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file ftrace/x86: Have static tracing also use ftrace_caller_setup ftrace/x86: Have static function tracing always test for function graph kprobes: Add IPMODIFY flag to kprobe_ftrace_ops ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict kprobes/ftrace: Recover original IP if pre_handler doesn't change it tracing/trivial: Fix typos and make an int into a bool tracing: Deletion of an unnecessary check before iput() ...
2014-12-10Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull EFI updates from Ingo Molnar: "Changes in this cycle are: - support module unload for efivarfs (Mathias Krause) - another attempt at moving x86 to libstub taking advantage of the __pure attribute (Ard Biesheuvel) - add EFI runtime services section to ptdump (Mathias Krause)" * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, ptdump: Add section for EFI runtime services efi/x86: Move x86 back to libstub efivarfs: Allow unloading when build as module
2014-11-19RAS/tracing: Use trace_seq_buffer_ptr() helper instead of open codedSteven Rostedt (Red Hat)1-1/+1
Use the helper function trace_seq_buffer_ptr() to get the current location of the next buffer write of a trace_seq object, instead of open coding it. This facilitates the conversion of trace_seq to use seq_buf. Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Borislav Petkov <bp@suse.de> Reviewed-by: Petr Mladek <pmladek@suse.cz> Cc: Chen Gong <gong.chen@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-11efi/x86: Move x86 back to libstubArd Biesheuvel1-1/+1
This reverts commit 84be880560fb, which itself reverted my original attempt to move x86 from #include'ing .c files from across the tree to using the EFI stub built as a static library. The issue that affected the original approach was that splitting the implementation into several .o files resulted in the variable 'efi_early' becoming a global with external linkage, which under -fPIC implies that references to it must go through the GOT. However, dealing with this additional GOT entry turned out to be troublesome on some EFI implementations. (GCC's visibility=hidden attribute is supposed to lift this requirement, but it turned out not to work on the 32-bit build.) Instead, use a pure getter function to get a reference to efi_early. This approach results in no additional GOT entries being generated, so there is no need for any changes in the early GOT handling. Tested-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-11-05efi: efi-stub: notify on DTB absenceMark Rutland1-1/+10
In the absence of a DTB configuration table, the EFI stub will happily continue attempting to boot a kernel, despite the fact that this kernel may not function without a description of the hardware. In this case, as with a typo'd "dtb=" option (e.g. "dbt=") or many other possible failures, the only output seen by the user will be the rather terse output from the EFI stub: EFI stub: Booting Linux Kernel... To aid those attempting to debug such failures, this patch adds a notice when no DTB is found, making the output more helpful: EFI stub: Booting Linux Kernel... EFI stub: Generating empty DTB Additionally, a positive acknowledgement is added when a user-specified DTB is in use: EFI stub: Booting Linux Kernel... EFI stub: Using DTB from command line Similarly, a positive acknowledgement is added when a DTB from a configuration table is in use: EFI stub: Booting Linux Kernel... EFI stub: Using DTB from configuration table Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Roy Franz <roy.franz@linaro.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-11-05efi: dmi: add support for SMBIOS 3.0 UEFI configuration tableArd Biesheuvel1-0/+4
This adds support to the UEFI side for detecting the presence of a SMBIOS 3.0 64-bit entry point. This allows the actual SMBIOS structure table to reside at a physical offset over 4 GB, which cannot be supported by the legacy SMBIOS 32-bit entry point. Since the firmware can legally provide both entry points, store the SMBIOS 3.0 entry point in a separate variable, and let the DMI decoding layer decide which one will be used. Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-10-03Merge branch 'next' into efi-next-mergeMatt Fleming5-19/+351
Conflicts: arch/x86/boot/compressed/eboot.c
2014-10-03efi: Delete the in_nmi() conditional runtime lockingMatt Fleming1-13/+4
commit 5dc3826d9f08 ("efi: Implement mandatory locking for UEFI Runtime Services") implemented some conditional locking when accessing variable runtime services that Ingo described as "pretty disgusting". The intention with the !efi_in_nmi() checks was to avoid live-locks when trying to write pstore crash data into an EFI variable. Such lockless accesses are allowed according to the UEFI specification when we're in a "non-recoverable" state, but whether or not things are implemented correctly in actual firmware implementations remains an unanswered question, and so it would seem sensible to avoid doing any kind of unsynchronized variable accesses. Furthermore, the efi_in_nmi() tests are inadequate because they don't account for the case where we call EFI variable services from panic or oops callbacks and aren't executing in NMI context. In other words, live-locking is still possible. Let's just remove the conditional locking altogether. Now we've got the ->set_variable_nonblocking() EFI variable operation we can abort if the runtime lock is already held. Aborting is by far the safest option. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03efi: Provide a non-blocking SetVariable() operationMatt Fleming2-0/+66
There are some circumstances that call for trying to write an EFI variable in a non-blocking way. One such scenario is when writing pstore data in efi_pstore_write() via the pstore_dump() kdump callback. Now that we have an EFI runtime spinlock we need a way of aborting if there is contention instead of spinning, since when writing pstore data from the kdump callback, the runtime lock may already be held by the CPU that's running the callback if we crashed in the middle of an EFI variable operation. The situation is sufficiently special that a new EFI variable operation is warranted. Introduce ->set_variable_nonblocking() for this use case. It is an optional EFI backend operation, and need only be implemented by those backends that usually acquire locks to serialize access to EFI variables, as is the case for virt_efi_set_variable() where we now grab the EFI runtime spinlock. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03efi: Resolve some shadow warningsMark Rustad1-7/+7
It is a really bad idea to declare variables or parameters that have the same name as common types. It is valid C, but it gets surprising if a macro expansion attempts to declare an inner local with that type. Change the local names to eliminate the hazard. Change s16 => str16, s8 => str8. This resolves warnings seen when using W=2 during make, for instance: drivers/firmware/efi/vars.c: In function ‘dup_variable_bug’: drivers/firmware/efi/vars.c:324:44: warning: declaration of ‘s16’ shadows a global declaration [-Wshadow] static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, drivers/firmware/efi/vars.c:328:8: warning: declaration of ‘s8’ shadows a global declaration [-Wshadow] char *s8; Signed-off-by: Mark Rustad <mark.d.rustad@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03efi: Introduce efi_md_typeattr_format()Laszlo Ersek1-0/+57
At the moment, there are three architectures debug-printing the EFI memory map at initialization: x86, ia64, and arm64. They all use different format strings, plus the EFI memory type and the EFI memory attributes are similarly hard to decode for a human reader. Introduce a helper __init function that formats the memory type and the memory attributes in a unified way, to a user-provided character buffer. The array "memory_type_name" is copied from the arm64 code, temporarily duplicating it. The (otherwise optional) braces around each string literal in the initializer list are dropped in order to match the kernel coding style more closely. The element size is tightened from 32 to 20 bytes (maximum actual string length + 1) so that we can derive the field width from the element size. Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [ Dropped useless 'register' keyword, which compiler will ignore ] Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03efi: Add kernel param efi=noruntimeDave Young1-0/+9
noefi kernel param means actually disabling efi runtime, Per suggestion from Leif Lindholm efi=noruntime should be better. But since noefi is already used in X86 thus just adding another param efi=noruntime for same purpose. Signed-off-by: Dave Young <dyoung@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03efi: Move noefi early param code out of x86 arch codeDave Young1-0/+13
noefi param can be used for arches other than X86 later, thus move it out of x86 platform code. Signed-off-by: Dave Young <dyoung@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>