kernel.git/arch/x86/platform, branch linux-5.6.y

efi/x86: Don't remap text<->rodata gap read-only for mixed mode

2020-05-02T06:50:48Z

commit f6103162008dfd37567f240b50e5e1ea7cf2e00c upstream. Commit d9e3d2c4f10320 ("efi/x86: Don't map the entire kernel text RW for mixed mode") updated the code that creates the 1:1 memory mapping to use read-only attributes for the 1:1 alias of the kernel's text and rodata sections, to protect it from inadvertent modification. However, it failed to take into account that the unused gap between text and rodata is given to the page allocator for general use. If the vmap'ed stack happens to be allocated from this region, any by-ref output arguments passed to EFI runtime services that are allocated on the stack (such as the 'datasize' argument taken by GetVariable() when invoked from efivar_entry_size()) will be referenced via a read-only mapping, resulting in a page fault if the EFI code tries to write to it: BUG: unable to handle page fault for address: 00000000386aae88 #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation PGD fd61063 P4D fd61063 PUD fd62063 PMD 386000e1 Oops: 0003 [#1] SMP PTI CPU: 2 PID: 255 Comm: systemd-sysv-ge Not tainted 5.6.0-rc4-default+ #22 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0008:0x3eaeed95 Code: ... <89> 03 be 05 00 00 80 a1 74 63 b1 3e 83 c0 48 e8 44 d2 ff ff eb 05 RSP: 0018:000000000fd73fa0 EFLAGS: 00010002 RAX: 0000000000000001 RBX: 00000000386aae88 RCX: 000000003e9f1120 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 000000000fd73fd8 R08: 00000000386aae88 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc0f040220000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f21160ac940(0000) GS:ffff9cf23d500000(0000) knlGS:0000000000000000 CS: 0008 DS: 0018 ES: 0018 CR0: 0000000080050033 CR2: 00000000386aae88 CR3: 000000000fd6c004 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: Modules linked in: CR2: 00000000386aae88 ---[ end trace a8bfbd202e712834 ]--- Let's fix this by remapping text and rodata individually, and leave the gaps mapped read-write. Fixes: d9e3d2c4f10320 ("efi/x86: Don't map the entire kernel text RW for mixed mode") Reported-by: Jiri Slaby Tested-by: Jiri Slaby Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200409130434.6736-10-ardb@kernel.org Signed-off-by: Greg Kroah-Hartman

efi/x86: Fix the deletion of variables in mixed mode

2020-04-17T14:13:49Z

[ Upstream commit a4b81ccfd4caba017d2b84720b6de4edd16911a0 ] efi_thunk_set_variable() treated the NULL "data" pointer as an invalid parameter, and this broke the deletion of variables in mixed mode. This commit fixes the check of data so that the userspace program can delete a variable in mixed mode. Fixes: 8319e9d5ad98ffcc ("efi/x86: Handle by-ref arguments covering multiple pages in mixed mode") Signed-off-by: Gary Lin Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200408081606.1504-1-glin@suse.com Link: https://lore.kernel.org/r/20200409130434.6736-9-ardb@kernel.org Signed-off-by: Sasha Levin

efi/x86: Add TPM related EFI tables to unencrypted mapping checks

2020-04-17T14:13:28Z

commit f10e80a19b07b58fc2adad7945f8313b01503bae upstream. When booting with SME active, EFI tables must be mapped unencrypted since they were built by UEFI in unencrypted memory. Update the list of tables to be checked during early_memremap() processing to account for the EFI TPM tables. This fixes a bug where an EFI TPM log table has been created by UEFI, but it lives in memory that has been marked as usable rather than reserved. Signed-off-by: Tom Lendacky Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar Cc: Thomas Gleixner Cc: David Hildenbrand Cc: Heinrich Schuchardt Cc: # v5.4+ Link: https://lore.kernel.org/r/4144cd813f113c20cdfa511cf59500a64e6015be.1582662842.git.thomas.lendacky@amd.com Link: https://lore.kernel.org/r/20200228121408.9075-2-ardb@kernel.org Signed-off-by: Greg Kroah-Hartman

efi/x86: Handle by-ref arguments covering multiple pages in mixed mode

2020-02-26T14:31:42Z

The mixed mode runtime wrappers are fragile when it comes to how the memory referred to by its pointer arguments are laid out in memory, due to the fact that it translates these addresses to physical addresses that the runtime services can dereference when running in 1:1 mode. Since vmalloc'ed pages (including the vmap'ed stack) are not contiguous in the physical address space, this scheme only works if the referenced memory objects do not cross page boundaries. Currently, the mixed mode runtime service wrappers require that all by-ref arguments that live in the vmalloc space have a size that is a power of 2, and are aligned to that same value. While this is a sensible way to construct an object that is guaranteed not to cross a page boundary, it is overly strict when it comes to checking whether a given object violates this requirement, as we can simply take the physical address of the first and the last byte, and verify that they point into the same physical page. When this check fails, we emit a WARN(), but then simply proceed with the call, which could cause data corruption if the next physical page belongs to a mapping that is entirely unrelated. Given that with vmap'ed stacks, this condition is much more likely to trigger, let's relax the condition a bit, but fail the runtime service call if it does trigger. Fixes: f6697df36bdf0bf7 ("x86/efi: Prevent mixed mode boot corruption with CONFIG_VMAP_STACK=y") Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar Cc: Thomas Gleixner Link: https://lore.kernel.org/r/20200221084849.26878-4-ardb@kernel.org

efi/x86: Remove support for EFI time and counter services in mixed mode

2020-02-26T14:31:42Z

Mixed mode calls at runtime are rather tricky with vmap'ed stacks, as we can no longer assume that data passed in by the callers of the EFI runtime wrapper routines is contiguous in physical memory. We need to fix this, but before we do, let's drop the implementations of routines that we know are never used on x86, i.e., the RTC related ones. Given that UEFI rev2.8 permits any runtime service to return EFI_UNSUPPORTED at runtime, let's return that instead. As get_next_high_mono_count() is never used at all, even on other architectures, let's make that return EFI_UNSUPPORTED too. Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar Cc: Thomas Gleixner Link: https://lore.kernel.org/r/20200221084849.26878-3-ardb@kernel.org

efi/x86: Align GUIDs to their size in the mixed mode runtime wrapper

2020-02-26T14:31:41Z

Hans reports that his mixed mode systems running v5.6-rc1 kernels hit the WARN_ON() in virt_to_phys_or_null_size(), caused by the fact that efi_guid_t objects on the vmap'ed stack happen to be misaligned with respect to their sizes. As a quick (i.e., backportable) fix, copy GUID pointer arguments to the local stack into a buffer that is naturally aligned to its size, so that it is guaranteed to cover only one physical page. Note that on x86, we cannot rely on the stack pointer being aligned the way the compiler expects, so we need to allocate an 8-byte aligned buffer of sufficient size, and copy the GUID into that buffer at an offset that is aligned to 16 bytes. Fixes: f6697df36bdf0bf7 ("x86/efi: Prevent mixed mode boot corruption with CONFIG_VMAP_STACK=y") Reported-by: Hans de Goede Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Tested-by: Hans de Goede Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar Cc: Thomas Gleixner Link: https://lore.kernel.org/r/20200221084849.26878-2-ardb@kernel.org

Merge tag 'efi-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-02-09T19:54:50Z

Pull EFI fix from Thomas Gleixner: "A single fix for a EFI boot regression on X86 which was caused by the recent rework of the EFI memory map parsing. On systems with invalid memmap entries the cleanup function uses an value which cannot be relied on in this stage. Use the actual EFI memmap entry instead" * tag 'efi-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/x86: Fix boot regression on systems with invalid memmap entries

proc: convert everything to "struct proc_ops"

2020-02-04T03:05:26Z

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86: mm+efi: convert ptdump_walk_pgd_level() to take a mm_struct

2020-02-04T03:05:25Z

To enable x86 to use the generic walk_page_range() function, the callers of ptdump_walk_pgd_level() need to pass an mm_struct rather than the raw pgd_t pointer. Luckily since commit 7e904a91bf60 ("efi: Use efi_mm in x86 as well as ARM") we now have an mm_struct for EFI on x86. Link: http://lkml.kernel.org/r/20191218162402.45610-18-steven.price@arm.com Signed-off-by: Steven Price Cc: Albert Ou Cc: Alexandre Ghiti Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Dave Hansen Cc: David S. Miller Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: James Hogan Cc: James Morse Cc: Jerome Glisse Cc: "Liang, Kan" Cc: Mark Rutland Cc: Michael Ellerman Cc: Paul Burton Cc: Paul Mackerras Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Ralf Baechle Cc: Russell King Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vineet Gupta Cc: Will Deacon Cc: Zong Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

efi/x86: Fix boot regression on systems with invalid memmap entries

2020-02-02T09:25:43Z

In efi_clean_memmap(), we do a pass over the EFI memory map to remove bogus entries that may be returned on certain systems. This recent commit: 1db91035d01aa8bf ("efi: Add tracking for dynamically allocated memmaps") refactored this code to pass the input to efi_memmap_install() via a temporary struct on the stack, which is populated using an initializer which inadvertently defines the value of its size field in terms of its desc_size field, which value cannot be relied upon yet in the initializer itself. Fix this by using efi.memmap.desc_size instead, which is where we get the value for desc_size from in the first place. Reported-by: Jörg Otte Tested-by: Jörg Otte Tested-by: Dan Williams Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: linux-efi@vger.kernel.org Cc: jrg.otte@gmail.com Cc: torvalds@linux-foundation.org Cc: mingo@kernel.org Link: https://lore.kernel.org/r/20200201233304.18322-1-ardb@kernel.org