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2020-02-23efi/libstub: Describe memory functionsHeinrich Schuchardt
Provide descriptions of: * efi_get_memory_map() * efi_low_alloc_above() * efi_free() Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20200218063038.3436-1-xypron.glpk@gmx.de Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Simplify efi_get_memory_map()Heinrich Schuchardt
Do not check the value of status twice. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Link: https://lore.kernel.org/r/20200216184050.3100-1-xypron.glpk@gmx.de Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Add function description of efi_allocate_pages()Heinrich Schuchardt
Provide a Sphinx style function description for efi_allocate_pages(). Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Link: https://lore.kernel.org/r/20200216171340.6070-1-xypron.glpk@gmx.de Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Make the LoadFile EFI protocol accessibleArd Biesheuvel
Add the protocol definitions, GUIDs and mixed mode glue so that the EFI loadfile protocol can be used from the stub. This will be used in a future patch to load the initrd. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Expose LocateDevicePath boot serviceArd Biesheuvel
We will be adding support for loading the initrd from a GUIDed device path in a subsequent patch, so update the prototype of the LocateDevicePath() boot service to make it callable from our code. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Clean up command line parsing routineArd Biesheuvel
We currently parse the command non-destructively, to avoid having to allocate memory for a copy before passing it to the standard parsing routines that are used by the core kernel, and which modify the input to delineate the parsed tokens with NUL characters. Instead, we call strstr() and strncmp() to go over the input multiple times, and match prefixes rather than tokens, which implies that we would match, e.g., 'nokaslrfoo' in the stub and disable KASLR, while the kernel would disregard the option and run with KASLR enabled. In order to avoid having to reason about whether and how this behavior may be abused, let's clean up the parsing routines, and rebuild them on top of the existing helpers. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Take soft and hard memory limits into account for initrd loadingArd Biesheuvel
On x86, the preferred load address of the initrd is still below 4 GB, even though in some cases, we can cope with an initrd that is loaded above that. To simplify the code, and to make it more straightforward to introduce other ways to load the initrd, pass the soft and hard memory limits at the same time, and let the code handling the initrd= command line option deal with this. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Rewrite file I/O routineArd Biesheuvel
The file I/O routine that is used to load initrd or dtb files from the EFI system partition suffers from a few issues: - it converts the u8[] command line back to a UTF-16 string, which is pointless since we only handle initrd or dtb arguments provided via the loaded image protocol anyway, which is where we got the UTF-16[] command line from in the first place when booting via the PE entry point, - in the far majority of cases, only a single initrd= option is present, but it optimizes for multiple options, by going over the command line twice, allocating heap buffers for dynamically sized arrays, etc. - the coding style is hard to follow, with few comments, and all logic including string parsing etc all combined in a single routine. Let's fix this by rewriting most of it, based on the idea that in the case of multiple initrds, we can just allocate a new, bigger buffer and copy over the data before freeing the old one. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move file I/O support code into separate fileArd Biesheuvel
Split off the file I/O support code into a separate source file so it ends up in a separate object file in the static library, allowing the linker to omit it if the routines are not used. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move get_dram_base() into arm-stub.cArd Biesheuvel
get_dram_base() is only called from arm-stub.c so move it into the same source file as its caller. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move efi_random_alloc() into separate source fileArd Biesheuvel
efi_random_alloc() is only used on arm64, but as it shares a source file with efi_random_get_seed(), the latter will pull in the former on other architectures as well. Let's take advantage of the fact that libstub is a static library, and so the linker will only incorporate objects that are needed to satisfy dependencies in other objects. This means we can move the random alloc code to a separate source file that gets built unconditionally, but only used when needed. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub/x86: Permit cmdline data to be allocated above 4 GBArd Biesheuvel
We now support cmdline data that is located in memory that is not 32-bit addressable, so relax the allocation limit on systems where this feature is enabled. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move stub specific declarations into efistub.hArd Biesheuvel
Move all the declarations that are only used in stub code from linux/efi.h to efistub.h which is only included locally. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub/x86: Permit bootparams struct to be allocated above 4 GBArd Biesheuvel
We now support bootparams structures that are located in memory that is not 32-bit addressable, so relax the allocation limit on systems where this feature is enabled. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Use consistent type names for file I/O protocolsArd Biesheuvel
Align the naming of efi_file_io_interface_t and efi_file_handle_t with the UEFI spec, and call them efi_simple_file_system_protocol_t and efi_file_protocol_t, respectively, using the same convention we use for all other type definitions that originate in the UEFI spec. While at it, move the definitions to efistub.h, so they are only seen by code that needs them. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub/x86: Incorporate eboot.c into libstubArd Biesheuvel
Most of the EFI stub source files of all architectures reside under drivers/firmware/efi/libstub, where they share a Makefile with special CFLAGS and an include file with declarations that are only relevant for stub code. Currently, we carry a lot of stub specific stuff in linux/efi.h only because eboot.c in arch/x86 needs them as well. So let's move eboot.c into libstub/, and move the contents of eboot.h that we still care about into efistub.h Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Simplify efi_high_alloc() and rename to efi_allocate_pages()Ard Biesheuvel
The implementation of efi_high_alloc() uses a complicated way of traversing the memory map to find an available region that is located as close as possible to the provided upper limit, and calls AllocatePages subsequently to create the allocation at that exact address. This is precisely what the EFI_ALLOCATE_MAX_ADDRESS allocation type argument to AllocatePages() does, and considering that EFI_ALLOC_ALIGN only exceeds EFI_PAGE_SIZE on arm64, let's use AllocatePages() directly and implement the alignment using code that the compiler can remove if it does not exceed EFI_PAGE_SIZE. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move memory map handling and allocation routines to mem.cArd Biesheuvel
Create a new source file mem.c to keep the routines involved in memory allocation and deallocation and manipulation of the EFI memory map. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub/arm: Relax FDT alignment requirementArd Biesheuvel
The arm64 kernel no longer requires the FDT blob to fit inside a naturally aligned 2 MB memory block, so remove the code that aligns the allocation to 2 MB. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Use hidden visibility for all source filesArd Biesheuvel
Instead of setting the visibility pragma for a small set of symbol declarations that could result in absolute references that we cannot support in the stub, declare hidden visibility for all code in the EFI stub, which is more robust and future proof. To ensure that the #pragma is taken into account before any other includes are processed, put it in a header file of its own and include it via the compiler command line using the -include option. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23Merge tag 'for-5.6-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "These are fixes that were found during testing with help of error injection, plus some other stable material. There's a fixup to patch added to rc1 causing locking in wrong context warnings, tests found one more deadlock scenario. The patches are tagged for stable, two of them now in the queue but we'd like all three released at the same time. I'm not happy about fixes to fixes in such a fast succession during rcs, but I hope we found all the fallouts of commit 28553fa992cb ('Btrfs: fix race between shrinking truncate and fiemap')" * tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents btrfs: fix bytes_may_use underflow in prealloc error condtition btrfs: handle logged extent failure properly btrfs: do not check delayed items are empty for single transaction cleanup btrfs: reset fs_root to NULL on error in open_ctree btrfs: destroy qgroup extent records on transaction abort
2020-02-23Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "More miscellaneous ext4 bug fixes (all stable fodder)" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix mount failure with quota configured as module jbd2: fix ocfs2 corrupt when clearing block group bits ext4: fix race between writepages and enabling EXT4_EXTENTS_FL ext4: rename s_journal_flag_rwsem to s_writepages_rwsem ext4: fix potential race between s_flex_groups online resizing and access ext4: fix potential race between s_group_info online resizing and access ext4: fix potential race between online resizing and write operations ext4: add cond_resched() to __ext4_find_entry() ext4: fix a data race in EXT4_I(inode)->i_disksize
2020-02-23Merge tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linuxLinus Torvalds
Pull csky updates from Guo Ren: "Sorry, I missed 5.6-rc1 merge window, but in this pull request the most are the fixes and the rests are between fixes and features. The only outside modification is the MAINTAINERS file update with our mailing list. - cache flush implementation fixes - ftrace modify panic fix - CONFIG_SMP boot problem fix - fix pt_regs saving for atomic.S - fix fixaddr_init without highmem. - fix stack protector support - fix fake Tightly-Coupled Memory code compile and use - fix some typos and coding convention" * tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linux: (23 commits) csky: Replace <linux/clk-provider.h> by <linux/of_clk.h> csky: Implement copy_thread_tls csky: Add PCI support csky: Minimize defconfig to support buildroot config.fragment csky: Add setup_initrd check code csky: Cleanup old Kconfig options arch/csky: fix some Kconfig typos csky: Fixup compile warning for three unimplemented syscalls csky: Remove unused cache implementation csky: Fixup ftrace modify panic csky: Add flush_icache_mm to defer flush icache all csky: Optimize abiv2 copy_to_user_page with VM_EXEC csky: Enable defer flush_dcache_page for abiv2 cpus (807/810/860) csky: Remove unnecessary flush_icache_* implementation csky: Support icache flush without specific instructions csky/Kconfig: Add Kconfig.platforms to support some drivers csky/smp: Fixup boot failed when CONFIG_SMP csky: Set regs->usp to kernel sp, when the exception is from kernel csky/mm: Fixup export invalid_pte_table symbol csky: Separate fixaddr_init from highmem ...
2020-02-23KVM: nVMX: Check IO instruction VM-exit conditionsOliver Upton
Consult the 'unconditional IO exiting' and 'use IO bitmaps' VM-execution controls when checking instruction interception. If the 'use IO bitmaps' VM-execution control is 1, check the instruction access against the IO bitmaps to determine if the instruction causes a VM-exit. Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-23KVM: nVMX: Refactor IO bitmap checks into helper functionOliver Upton
Checks against the IO bitmap are useful for both instruction emulation and VM-exit reflection. Refactor the IO bitmap checks into a helper function. Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-23KVM: nVMX: Don't emulate instructions in guest modePaolo Bonzini
vmx_check_intercept is not yet fully implemented. To avoid emulating instructions disallowed by the L1 hypervisor, refuse to emulate instructions by default. Cc: stable@vger.kernel.org [Made commit, added commit msg - Oliver] Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-23KVM: nVMX: Emulate MTF when performing instruction emulationOliver Upton
Since commit 5f3d45e7f282 ("kvm/x86: add support for MONITOR_TRAP_FLAG"), KVM has allowed an L1 guest to use the monitor trap flag processor-based execution control for its L2 guest. KVM simply forwards any MTF VM-exits to the L1 guest, which works for normal instruction execution. However, when KVM needs to emulate an instruction on the behalf of an L2 guest, the monitor trap flag is not emulated. Add the necessary logic to kvm_skip_emulated_instruction() to synthesize an MTF VM-exit to L1 upon instruction emulation for L2. Fixes: 5f3d45e7f282 ("kvm/x86: add support for MONITOR_TRAP_FLAG") Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-23KVM: fix error handling in svm_hardware_setupLi RongQing
rename svm_hardware_unsetup as svm_hardware_teardown, move it before svm_hardware_setup, and call it to free all memory if fail to setup in svm_hardware_setup, otherwise memory will be leaked remove __exit attribute for it since it is called in __init function Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-22net: genetlink: return the error code when attribute parsing fails.Paolo Abeni
Currently if attribute parsing fails and the genl family does not support parallel operation, the error code returned by __nlmsg_parse() is discarded by genl_family_rcv_msg_attrs_parse(). Be sure to report the error for all genl families. Fixes: c10e6cf85e7d ("net: genetlink: push attrbuf allocation and parsing to a separate function") Fixes: ab5b526da048 ("net: genetlink: always allocate separate attrs for dumpit ops") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-22ipv4: ensure rcu_read_lock() in cipso_v4_error()Matteo Croce
Similarly to commit c543cb4a5f07 ("ipv4: ensure rcu_read_lock() in ipv4_link_failure()"), __ip_options_compile() must be called under rcu protection. Fixes: 3da1ed7ac398 ("net: avoid use IPCB in cipso_v4_error") Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Matteo Croce <mcroce@redhat.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-22vhost: Check docket sk_family instead of call getnameEugenio Pérez
Doing so, we save one call to get data we already have in the struct. Also, since there is no guarantee that getname use sockaddr_ll parameter beyond its size, we add a little bit of security here. It should do not do beyond MAX_ADDR_LEN, but syzbot found that ax25_getname writes more (72 bytes, the size of full_sockaddr_ax25, versus 20 + 32 bytes of sockaddr_ll + MAX_ADDR_LEN in syzbot repro). Fixes: 3a4d5c94e9593 ("vhost_net: a kernel-level virtio server") Reported-by: syzbot+f2a62d07a5198c819c7b@syzkaller.appspotmail.com Signed-off-by: Eugenio Pérez <eperezma@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-23csky: Replace <linux/clk-provider.h> by <linux/of_clk.h>Geert Uytterhoeven
The C-Sky platform code is not a clock provider, and just needs to call of_clk_init(). Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
2020-02-22Merge tag 'ras-urgent-2020-02-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RAS fixes from Thomas Gleixner: "Two fixes for the AMD MCE driver: - Populate the per CPU MCA bank descriptor pointer only after it has been completely set up to prevent a use-after-free in case that one of the subsequent initialization step fails - Implement a proper release function for the sysfs entries of MCA threshold controls instead of freeing the memory right in the CPU teardown code, which leads to another use-after-free when the associated sysfs file is opened and accessed" * tag 'ras-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce/amd: Fix kobject lifetime x86/mce/amd: Publish the bank pointer only after setup has succeeded
2020-02-22audit: fix error handling in audit_data_to_entry()Paul Moore
Commit 219ca39427bf ("audit: use union for audit_field values since they are mutually exclusive") combined a number of separate fields in the audit_field struct into a single union. Generally this worked just fine because they are generally mutually exclusive. Unfortunately in audit_data_to_entry() the overlap can be a problem when a specific error case is triggered that causes the error path code to attempt to cleanup an audit_field struct and the cleanup involves attempting to free a stored LSM string (the lsm_str field). Currently the code always has a non-NULL value in the audit_field.lsm_str field as the top of the for-loop transfers a value into audit_field.val (both .lsm_str and .val are part of the same union); if audit_data_to_entry() fails and the audit_field struct is specified to contain a LSM string, but the audit_field.lsm_str has not yet been properly set, the error handling code will attempt to free the bogus audit_field.lsm_str value that was set with audit_field.val at the top of the for-loop. This patch corrects this by ensuring that the audit_field.val is only set when needed (it is cleared when the audit_field struct is allocated with kcalloc()). It also corrects a few other issues to ensure that in case of error the proper error code is returned. Cc: stable@vger.kernel.org Fixes: 219ca39427bf ("audit: use union for audit_field values since they are mutually exclusive") Reported-by: syzbot+1f4d90ead370d72e450b@syzkaller.appspotmail.com Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-22Merge tag 'irq-urgent-2020-02-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "Two fixes for the irq core code which are follow ups to the recent MSI fixes: - The WARN_ON which was put into the MSI setaffinity callback for paranoia reasons actually triggered via a callchain which escaped when all the possible ways to reach that code were analyzed. The proc/irq/$N/*affinity interfaces have a quirk which came in when ALPHA moved to the generic interface: In case that the written affinity mask does not contain any online CPU it calls into ALPHAs magic auto affinity setting code. A few years later this mechanism was also made available to x86 for no good reasons and in a way which circumvents all sanity checks for interrupts which cannot have their affinity set from process context on X86 due to the way the X86 interrupt delivery works. It would be possible to make this work properly, but there is no point in doing so. If the interrupt is not yet started then the affinity setting has no effect and if it is started already then it is already assigned to an online CPU so there is no point to randomly move it to some other CPU. Just return EINVAL as the code has done before that change forever. - The new MSI quirk bit in the irq domain flags turned out to be already occupied, which escaped the author and the reviewers because the already in use bits were 0,6,2,3,4,5 listed in that order. That bit 6 was simply overlooked because the ordering was straight forward linear otherwise. So the new bit ended up being a duplicate. Fix it up by switching the oddball 6 to the obvious 1" * tag 'irq-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/irqdomain: Make sure all irq domain flags are distinct genirq/proc: Reject invalid affinity masks (again)
2020-02-22Merge tag 'x86-urgent-2020-02-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Two fixes for x86: - Remove the __force_oder definiton from the kaslr boot code as it is already defined in the page table code which makes GCC 10 builds fail because it changed the default to -fno-common. - Address the AMD erratum 1054 concerning the IRPERF capability and enable the Instructions Retired fixed counter on machines which are not affected by the erratum" * tag 'x86-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu/amd: Enable the fixed Instructions Retired counter IRPERF x86/boot/compressed: Don't declare __force_order in kaslr_64.c
2020-02-22efi/libstub/x86: Avoid overflowing code32_start on PE entryArd Biesheuvel
When using the native PE entry point (as opposed to the EFI handover protocol entry point that is used more widely), we set code32_start, which is a 32-bit wide field, to the effective symbol address of startup_32, which could overflow given that the EFI loader may have located the running image anywhere in memory, and we haven't reached the point yet where we relocate ourselves. Since we relocate ourselves if code32_start != pref_address, this isn't likely to lead to problems in practice, given how unlikely it is that the truncated effective address of startup_32 happens to equal pref_address. But it is better to defer the assignment of code32_start to after the relocation, when it is guaranteed to fit. While at it, move the call to efi_relocate_kernel() to an earlier stage so it is more likely that our preferred offset in memory has not been occupied by other memory allocations done in the mean time. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/libstub/x86: Remove pointless zeroing of apm_bios_infoArd Biesheuvel
We have some code in the EFI stub entry point that takes the address of the apm_bios_info struct in the newly allocated and zeroed out boot_params structure, only to zero it out again. This is pointless so remove it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/apple-properties: Replace zero-length array with flexible-array memberGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Link: https://lore.kernel.org/r/20200211231421.GA15697@embeddedor Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/libstub/arm64: Use 1:1 mapping of RT services if property table existsArd Biesheuvel
The UEFI spec defines (and deprecates) a misguided and shortlived memory protection feature that is based on splitting memory regions covering PE/COFF executables into separate code and data regions, without annotating them as belonging to the same executable image. When the OS assigns the virtual addresses of these regions, it may move them around arbitrarily, without taking into account that the PE/COFF code sections may contain relative references into the data sections, which means the relative placement of these segments has to be preserved or the executable image will be corrupted. The original workaround on arm64 was to ensure that adjacent regions of the same type were mapped adjacently in the virtual mapping, but this requires sorting of the memory map, which we would prefer to avoid. Considering that the native physical mapping of the PE/COFF images does not suffer from this issue, let's preserve it at runtime, and install it as the virtual mapping as well. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/bgrt: Accept BGRT tables with a version of 0Hans de Goede
Some (somewhat older) laptops have a correct BGRT table, except that the version field is 0 instead of 1. This has been seen on several Ivy Bridge based Lenovo models. For now the spec. only defines version 1, so it is reasonably safe to assume that tables with a version of 0 really are version 1 too, which is what this commit does so that the BGRT table will be accepted by the kernel on laptop models with this issue. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200131130623.33875-1-hdegoede@redhat.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/x86: Mark setup_graphics staticArvind Sankar
This function is only called from efi_main in the same source file. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200130222004.1932152-1-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22x86/boot: Micro-optimize GDT loading instructionsArvind Sankar
Rearrange the instructions a bit to use a 32-bit displacement once instead of 2/3 times. This saves 8 bytes of machine code. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200202171353.3736319-8-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22x86/boot: GDT limit value should be size - 1Arvind Sankar
The limit value for the GDTR should be such that adding it to the base address gives the address of the last byte of the GDT, i.e. it should be one less than the size, not the size. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200202171353.3736319-7-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/x86: Remove GDT setup from efi_mainArvind Sankar
The 64-bit kernel will already load a GDT in startup_64, which is the next function to execute after return from efi_main. Add GDT setup code to the 32-bit kernel's startup_32 as well. Doing it in the head code has the advantage that we can avoid potentially corrupting the GDT during copy/decompression. This also removes dependence on having a specific GDT layout setup by the bootloader. Both startup_32 and startup_64 now clear interrupts on entry, so we can remove that from efi_main as well. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200202171353.3736319-6-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22x86/boot: Clear direction and interrupt flags in startup_64Arvind Sankar
startup_32 already clears these flags on entry, do it in startup_64 as well for consistency. The direction flag in particular is not specified to be cleared in the boot protocol documentation, and we currently call into C code (paging_prepare) without explicitly clearing it. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200202171353.3736319-5-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22x86/boot: Reload GDTR after copying to the end of the bufferArvind Sankar
The GDT may get overwritten during the copy or during extract_kernel, which will cause problems if any segment register is touched before the GDTR is reloaded by the decompressed kernel. For safety update the GDTR to point to the GDT within the copied kernel. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200202171353.3736319-4-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/x86: Don't depend on firmware GDT layoutArvind Sankar
When booting in mixed mode, the firmware's GDT is still installed at handover entry in efi32_stub_entry. We save the GDTR for later use in __efi64_thunk but we are assuming that descriptor 2 (__KERNEL_CS) is a valid 32-bit code segment descriptor and that descriptor 3 (__KERNEL_DS/__BOOT_DS) is a valid data segment descriptor. This happens to be true for OVMF (it actually uses descriptor 1 for data segments, but descriptor 3 is also setup as data), but we shouldn't depend on this being the case. Fix this by saving the code and data selectors in addition to the GDTR in efi32_stub_entry, and restoring them in __efi64_thunk before calling the firmware. The UEFI specification guarantees that selectors will be flat, so using the DS selector for all the segment registers should be enough. We also need to install our own GDT before initializing segment registers in startup_32, so move the GDT load up to the beginning of the function. [ardb: mention mixed mode in the commit log] Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200202171353.3736319-3-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22x86/boot: Remove KEEP_SEGMENTS supportArvind Sankar
Commit a24e785111a3 ("i386: paravirt boot sequence") added this flag for use by paravirtualized environments such as Xen. However, Xen never made use of this flag [1], and it was only ever used by lguest [2]. Commit ecda85e70277 ("x86/lguest: Remove lguest support") removed lguest, so KEEP_SEGMENTS has lost its last user. [1] https://lore.kernel.org/lkml/4D4B097C.5050405@goop.org [2] https://www.mail-archive.com/lguest@lists.ozlabs.org/msg00469.html Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200202171353.3736319-2-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/libstub/arm: Make efi_entry() an ordinary PE/COFF entrypointArd Biesheuvel
Expose efi_entry() as the PE/COFF entrypoint directly, instead of jumping into a wrapper that fiddles with stack buffers and other stuff that the compiler is much better at. The only reason this code exists is to obtain a pointer to the base of the image, but we can get the same value from the loaded_image protocol, which we already need for other reasons anyway. Update the return type as well, to make it consistent with what is required for a PE/COFF executable entrypoint. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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