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2016-02-22x86/efi: Only map kernel text for EFI mixed modeSai Praneeth
The correct symbol to use when figuring out the size of the kernel text is '_etext', not '_end' which is the symbol for the entire kernel image includes data and debug sections. Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1455712566-16727-14-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-22x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tablesSai Praneeth
Now that we have EFI memory region bits that indicate which regions do not need execute permission or read/write permission in the page tables, let's use them. We also check for EFI_NX_PE_DATA and only enforce the restrictive mappings if it's present (to allow us to ignore buggy firmware that sets bits it didn't mean to and to preserve backwards compatibility). Instead of assuming that firmware would set appropriate attributes in memory descriptor like EFI_MEMORY_RO for code and EFI_MEMORY_XP for data, we can expect some firmware out there which might only set *type* in memory descriptor to be EFI_RUNTIME_SERVICES_CODE or EFI_RUNTIME_SERVICES_DATA leaving away attribute. This will lead to improper mappings of EFI runtime regions. In order to avoid it, we check attribute and type of memory descriptor to update mappings and moreover Windows works this way. Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1455712566-16727-13-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-22x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd()Sai Praneeth
As part of the preparation for the EFI_MEMORY_RO flag added in the UEFI 2.5 specification, we need the ability to map pages in kernel page tables without _PAGE_RW being set. Modify kernel_map_pages_in_pgd() to require its callers to pass _PAGE_RW if the pages need to be mapped read/write. Otherwise, we'll map the pages as read-only. Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1455712566-16727-12-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-19Merge tag 'efi-next' of ↵Thomas Gleixner
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efi Pull efi changes from Matt Fleming: * We don't need to carry our own formatting code in the esrt driver because the kobject API can do that for us - Rasmus Villemoes * Update the arm64 file paths in Documentation/efi-stub.txt to match the current tree - Alan Ott * Consistently preface all print statements with "efi" arch/x86 so that it's more obvious to users reporting problems which statements in the kernel log are relevant for EFI - Matt Fleming * Fix a boot crash in the ACPI BGRT driver and delete efi_lookup_mapped_addr() since it's useless now that the EFI mappings *only* exist in the 'efi_pgd' page table. Instead we always early_memremap() the BGRT memory - Sai Praneeth Prakhya
2015-12-14x86/efi: Preface all print statements with efi* tagMatt Fleming
The pr_*() calls in the x86 EFI code may or may not include a subsystem tag, which makes it difficult to grep the kernel log for all relevant EFI messages and leads users to miss important information. Recently, a bug reporter provided all the EFI print messages from the kernel log when trying to diagnose an issue but missed the following statement because it wasn't prefixed with anything indicating it was related to EFI, pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap); Cc: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2015-11-29x86/efi: Build our own page table structuresMatt Fleming
With commit e1a58320a38d ("x86/mm: Warn on W^X mappings") all users booting on 64-bit UEFI machines see the following warning, ------------[ cut here ]------------ WARNING: CPU: 7 PID: 1 at arch/x86/mm/dump_pagetables.c:225 note_page+0x5dc/0x780() x86/mm: Found insecure W+X mapping at address ffff88000005f000/0xffff88000005f000 ... x86/mm: Checked W+X mappings: FAILED, 165660 W+X pages found. ... This is caused by mapping EFI regions with RWX permissions. There isn't much we can do to restrict the permissions for these regions due to the way the firmware toolchains mix code and data, but we can at least isolate these mappings so that they do not appear in the regular kernel page tables. In commit d2f7cbe7b26a ("x86/efi: Runtime services virtual mapping") we started using 'trampoline_pgd' to map the EFI regions because there was an existing identity mapping there which we use during the SetVirtualAddressMap() call and for broken firmware that accesses those addresses. But 'trampoline_pgd' shares some PGD entries with 'swapper_pg_dir' and does not provide the isolation we require. Notably the virtual address for __START_KERNEL_map and MODULES_START are mapped by the same PGD entry so we need to be more careful when copying changes over in efi_sync_low_kernel_mappings(). This patch doesn't go the full mile, we still want to share some PGD entries with 'swapper_pg_dir'. Having completely separate page tables brings its own issues such as synchronising new mappings after memory hotplug and module loading. Sharing also keeps memory usage down. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-6-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-29x86/efi: Hoist page table switching code into efi_call_virt()Matt Fleming
This change is a prerequisite for pending patches that switch to a dedicated EFI page table, instead of using 'trampoline_pgd' which shares PGD entries with 'swapper_pg_dir'. The pending patches make it impossible to dereference the runtime service function pointer without first switching %cr3. It's true that we now have duplicated switching code in efi_call_virt() and efi_call_phys_{prolog,epilog}() but we are sacrificing code duplication for a little more clarity and the ease of writing the page table switching code in C instead of asm. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-5-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-29x86/efi: Map RAM into the identity page table for mixed modeMatt Fleming
We are relying on the pre-existing mappings in 'trampoline_pgd' when accessing function arguments in the EFI mixed mode thunking code. Instead let's map memory explicitly so that things will continue to work when we move to a separate page table in the future. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-4-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-29x86/mm/pat: Ensure cpa->pfn only contains page frame numbersMatt Fleming
The x86 pageattr code is confused about the data that is stored in cpa->pfn, sometimes it's treated as a page frame number, sometimes it's treated as an unshifted physical address, and in one place it's treated as a pte. The result of this is that the mapping functions do not map the intended physical address. This isn't a problem in practice because most of the addresses we're mapping in the EFI code paths are already mapped in 'trampoline_pgd' and so the pageattr mapping functions don't actually do anything in this case. But when we move to using a separate page table for the EFI runtime this will be an issue. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01efi: Clean up the efi_call_phys_[prolog|epilog]() save/restore interactionIngo Molnar
Currently x86-64 efi_call_phys_prolog() saves into a global variable (save_pgd), and efi_call_phys_epilog() restores the kernel pagetables from that global variable. Change this to a cleaner save/restore pattern where the saving function returns the saved object and the restore function restores that. Apply the same concept to the 32-bit code as well. Plus this approach, as an added bonus, allows us to express the !efi_enabled(EFI_OLD_MEMMAP) situation in a clean fashion as well, via a 'NULL' return value. Cc: Tapasweni Pathak <tapaswenipathak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-04-01efi: Disable interrupts around EFI calls, not in the epilog/prolog callsIngo Molnar
Tapasweni Pathak reported that we do a kmalloc() in efi_call_phys_prolog() on x86-64 while having interrupts disabled, which is a big no-no, as kmalloc() can sleep. Solve this by removing the irq disabling from the prolog/epilog calls around EFI calls: it's unnecessary, as in this stage we are single threaded in the boot thread, and we don't ever execute this from interrupt contexts. Reported-by: Tapasweni Pathak <tapaswenipathak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-11-11x86, ptdump: Add section for EFI runtime servicesMathias Krause
In commit 3891a04aafd6 ("x86-64, espfix: Don't leak bits 31:16 of %esp returning..") the "ESPFix Area" was added to the page table dump special sections. That area, though, has a limited amount of entries printed. The EFI runtime services are, unfortunately, located in-between the espfix area and the high kernel memory mapping. Due to the enforced limitation for the espfix area, the EFI mappings won't be printed in the page table dump. To make the ESP runtime service mappings visible again, provide them a dedicated entry. Signed-off-by: Mathias Krause <minipli@googlemail.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03x86/efi: Mark initialization code as suchMathias Krause
The 32 bit and 64 bit implementations differ in their __init annotations for some functions referenced from the common EFI code. Namely, the 32 bit variant is missing some of the __init annotations the 64 bit variant has. To solve the colliding annotations, mark the corresponding functions in efi_32.c as initialization code, too -- as it is such. Actually, quite a few more functions are only used during initialization and therefore can be marked __init. They are therefore annotated, too. Also add the __init annotation to the prototypes in the efi.h header so users of those functions will see it's meant as initialization code only. This patch also fixes the "prelog" typo. ("prologue" / "epilogue" might be more appropriate but this is C code after all, not an opera! :D) Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-17x86/efi: Restore 'attr' argument to query_variable_info()Matt Fleming
In the thunk patches the 'attr' argument was dropped to query_variable_info(). Restore it otherwise the firmware will return EFI_INVALID_PARAMETER. Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-05Merge remote-tracking branch 'tip/x86/efi-mixed' into efi-for-mingoMatt Fleming
Conflicts: arch/x86/kernel/setup.c arch/x86/platform/efi/efi.c arch/x86/platform/efi/efi_64.c
2014-03-04x86/efi: Add mixed runtime services supportMatt Fleming
Setup the runtime services based on whether we're booting in EFI native mode or not. For non-native mode we need to thunk from 64-bit into 32-bit mode before invoking the EFI runtime services. Using the runtime services after SetVirtualAddressMap() is slightly more complicated because we need to ensure that all the addresses we pass to the firmware are below the 4GB boundary so that they can be addressed with 32-bit pointers, see efi_setup_page_tables(). Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-04x86/efi: Make efi virtual runtime map passing more robustBorislav Petkov
Currently, running SetVirtualAddressMap() and passing the physical address of the virtual map array was working only by a lucky coincidence because the memory was present in the EFI page table too. Until Toshi went and booted this on a big HP box - the krealloc() manner of resizing the memmap we're doing did allocate from such physical addresses which were not mapped anymore and boom: http://lkml.kernel.org/r/1386806463.1791.295.camel@misato.fc.hp.com One way to take care of that issue is to reimplement the krealloc thing but with pages. We start with contiguous pages of order 1, i.e. 2 pages, and when we deplete that memory (shouldn't happen all that often but you know firmware) we realloc the next power-of-two pages. Having the pages, it is much more handy and easy to map them into the EFI page table with the already existing mapping code which we're using for building the virtual mappings. Thanks to Toshi Kani and Matt for the great debugging help. Reported-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-04x86/efi: Dump the EFI page tableBorislav Petkov
This is very useful for debugging issues with the recently added pagetable switching code for EFI virtual mode. Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-02-14x86/efi: Fix 32-bit falloutBorislav Petkov
We do not enable the new efi memmap on 32-bit and thus we need to run runtime_code_page_mkexec() unconditionally there. Fix that. Reported-and-tested-by: Lejun Zhu <lejun.zhu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-12-29x86/efi: Delete superfluous global variablesMatt Fleming
There's no need to save the runtime map details in global variables, the values are only required to pass to efi_runtime_map_setup(). And because 'nr_efi_runtime_map' isn't needed, get_nr_runtime_map() can be deleted along with 'efi_data_len'. Cc: Dave Young <dyoung@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-12-29x86/efi: Pass necessary EFI data for kexec via setup_dataDave Young
Add a new setup_data type SETUP_EFI for kexec use. Passing the saved fw_vendor, runtime, config tables and EFI runtime mappings. When entering virtual mode, directly mapping the EFI runtime regions which we passed in previously. And skip the step to call SetVirtualAddressMap(). Specially for HP z420 workstation we need save the smbios physical address. The kernel boot sequence proceeds in the following order. Step 2 requires efi.smbios to be the physical address. However, I found that on HP z420 EFI system table has a virtual address of SMBIOS in step 1. Hence, we need set it back to the physical address with the smbios in efi_setup_data. (When it is still the physical address, it simply sets the same value.) 1. efi_init() - Set efi.smbios from EFI system table 2. dmi_scan_machine() - Temporary map efi.smbios to access SMBIOS table 3. efi_enter_virtual_mode() - Map EFI ranges Tested on ovmf+qemu, lenovo thinkpad, a dell laptop and an HP z420 workstation. Signed-off-by: Dave Young <dyoung@redhat.com> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-12-21x86/efi: Add a wrapper function efi_map_region_fixed()Dave Young
Kexec kernel will use saved runtime virtual mapping, so add a new function efi_map_region_fixed() for directly mapping a md to md->virt. The md is passed in from 1st kernel, the virtual addr is saved in md->virt_addr. Signed-off-by: Dave Young <dyoung@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-12-21x86/efi: Remove unused variables in __map_region()Dave Young
variables size and end is useless in this function, thus remove them. Reported-by: Toshi Kani <toshi.kani@hp.com> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Dave Young <dyoung@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-11-02x86/efi: Runtime services virtual mappingBorislav Petkov
We map the EFI regions needed for runtime services non-contiguously, with preserved alignment on virtual addresses starting from -4G down for a total max space of 64G. This way, we provide for stable runtime services addresses across kernels so that a kexec'd kernel can still use them. Thus, they're mapped in a separate pagetable so that we don't pollute the kernel namespace. Add an efi= kernel command line parameter for passing miscellaneous options and chicken bits from the command line. While at it, add a chicken bit called "efi=old_map" which can be used as a fallback to the old runtime services mapping method in case there's some b0rkage with a particular EFI implementation (haha, it is hard to hold up the sarcasm here...). Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-04-29Include missing linux/slab.h inclusionsDavid Howells
Include missing linux/slab.h inclusions where the source file is currently expecting to get kmalloc() and co. through linux/proc_fs.h. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: linux-s390@vger.kernel.org cc: sparclinux@vger.kernel.org cc: linux-efi@vger.kernel.org cc: linux-mtd@lists.infradead.org cc: devel@driverdev.osuosl.org cc: x86@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-18efi, x86: Pass a proper identity mapping in efi_call_phys_prelogNathan Zimmer
Update efi_call_phys_prelog to install an identity mapping of all available memory. This corrects a bug on very large systems with more then 512 GB in which bios would not be able to access addresses above not in the mapping. The result is a crash that looks much like this. BUG: unable to handle kernel paging request at 000000effd870020 IP: [<0000000078bce331>] 0x78bce330 PGD 0 Oops: 0000 [#1] SMP Modules linked in: CPU 0 Pid: 0, comm: swapper/0 Tainted: G W 3.8.0-rc1-next-20121224-medusa_ntz+ #2 Intel Corp. Stoutland Platform RIP: 0010:[<0000000078bce331>] [<0000000078bce331>] 0x78bce330 RSP: 0000:ffffffff81601d28 EFLAGS: 00010006 RAX: 0000000078b80e18 RBX: 0000000000000004 RCX: 0000000000000004 RDX: 0000000078bcf958 RSI: 0000000000002400 RDI: 8000000000000000 RBP: 0000000078bcf760 R08: 000000effd870000 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000000c3 R12: 0000000000000030 R13: 000000effd870000 R14: 0000000000000000 R15: ffff88effd870000 FS: 0000000000000000(0000) GS:ffff88effe400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000effd870020 CR3: 000000000160c000 CR4: 00000000000006b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process swapper/0 (pid: 0, threadinfo ffffffff81600000, task ffffffff81614400) Stack: 0000000078b80d18 0000000000000004 0000000078bced7b ffff880078b81fff 0000000000000000 0000000000000082 0000000078bce3a8 0000000000002400 0000000060000202 0000000078b80da0 0000000078bce45d ffffffff8107cb5a Call Trace: [<ffffffff8107cb5a>] ? on_each_cpu+0x77/0x83 [<ffffffff8102f4eb>] ? change_page_attr_set_clr+0x32f/0x3ed [<ffffffff81035946>] ? efi_call4+0x46/0x80 [<ffffffff816c5abb>] ? efi_enter_virtual_mode+0x1f5/0x305 [<ffffffff816aeb24>] ? start_kernel+0x34a/0x3d2 [<ffffffff816ae5ed>] ? repair_env_string+0x60/0x60 [<ffffffff816ae2be>] ? x86_64_start_reservations+0xba/0xc1 [<ffffffff816ae120>] ? early_idt_handlers+0x120/0x120 [<ffffffff816ae419>] ? x86_64_start_kernel+0x154/0x163 Code: Bad RIP value. RIP [<0000000078bce331>] 0x78bce330 RSP <ffffffff81601d28> CR2: 000000effd870020 ---[ end trace ead828934fef5eab ]--- Cc: stable@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2012-12-15Revert "x86-64/efi: Use EFI to deal with platform wall clock (again)"Linus Torvalds
This reverts commit bd52276fa1d4 ("x86-64/efi: Use EFI to deal with platform wall clock (again)"), and the two supporting commits: da5a108d05b4: "x86/kernel: remove tboot 1:1 page table creation code" 185034e72d59: "x86, efi: 1:1 pagetable mapping for virtual EFI calls") as they all depend semantically on commit 53b87cf088e2 ("x86, mm: Include the entire kernel memory map in trampoline_pgd") that got reverted earlier due to the problems it caused. This was pointed out by Yinghai Lu, and verified by me on my Macbook Air that uses EFI. Pointed-out-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-14Merge branch 'core-efi-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 EFI update from Peter Anvin: "EFI tree, from Matt Fleming. Most of the patches are the new efivarfs filesystem by Matt Garrett & co. The balance are support for EFI wallclock in the absence of a hardware-specific driver, and various fixes and cleanups." * 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) efivarfs: Make efivarfs_fill_super() static x86, efi: Check table header length in efi_bgrt_init() efivarfs: Use query_variable_info() to limit kmalloc() efivarfs: Fix return value of efivarfs_file_write() efivarfs: Return a consistent error when efivarfs_get_inode() fails efivarfs: Make 'datasize' unsigned long efivarfs: Add unique magic number efivarfs: Replace magic number with sizeof(attributes) efivarfs: Return an error if we fail to read a variable efi: Clarify GUID length calculations efivarfs: Implement exclusive access for {get,set}_variable efivarfs: efivarfs_fill_super() ensure we clean up correctly on error efivarfs: efivarfs_fill_super() ensure we free our temporary name efivarfs: efivarfs_fill_super() fix inode reference counts efivarfs: efivarfs_create() ensure we drop our reference on inode on error efivarfs: efivarfs_file_read ensure we free data in error paths x86-64/efi: Use EFI to deal with platform wall clock (again) x86/kernel: remove tboot 1:1 page table creation code x86, efi: 1:1 pagetable mapping for virtual EFI calls x86, mm: Include the entire kernel memory map in trampoline_pgd ...
2012-10-30x86, efi: 1:1 pagetable mapping for virtual EFI callsMatt Fleming
Some firmware still needs a 1:1 (virt->phys) mapping even after we've called SetVirtualAddressMap(). So install the mapping alongside our existing kernel mapping whenever we make EFI calls in virtual mode. This bug was discovered on ASUS machines where the firmware implementation of GetTime() accesses the RTC device via physical addresses, even though that's bogus per the UEFI spec since we've informed the firmware via SetVirtualAddressMap() that the boottime memory map is no longer valid. This bug seems to be present in a lot of consumer devices, so there's not a lot we can do about this spec violation apart from workaround it. Cc: JérômeCarretero <cJ-ko@zougloub.eu> Cc: Vasco Dias <rafa.vasco@gmail.com> Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2012-10-24x86/efi: Fix oops caused by incorrect set_memory_uc() usageMatt Fleming
Calling __pa() with an ioremap'd address is invalid. If we encounter an efi_memory_desc_t without EFI_MEMORY_WB set in ->attribute we currently call set_memory_uc(), which in turn calls __pa() on a potentially ioremap'd address. On CONFIG_X86_32 this results in the following oops: BUG: unable to handle kernel paging request at f7f22280 IP: [<c10257b9>] reserve_ram_pages_type+0x89/0x210 *pdpt = 0000000001978001 *pde = 0000000001ffb067 *pte = 0000000000000000 Oops: 0000 [#1] PREEMPT SMP Modules linked in: Pid: 0, comm: swapper Not tainted 3.0.0-acpi-efi-0805 #3 EIP: 0060:[<c10257b9>] EFLAGS: 00010202 CPU: 0 EIP is at reserve_ram_pages_type+0x89/0x210 EAX: 0070e280 EBX: 38714000 ECX: f7814000 EDX: 00000000 ESI: 00000000 EDI: 38715000 EBP: c189fef0 ESP: c189fea8 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 Process swapper (pid: 0, ti=c189e000 task=c18bbe60 task.ti=c189e000) Stack: 80000200 ff108000 00000000 c189ff00 00038714 00000000 00000000 c189fed0 c104f8ca 00038714 00000000 00038715 00000000 00000000 00038715 00000000 00000010 38715000 c189ff48 c1025aff 38715000 00000000 00000010 00000000 Call Trace: [<c104f8ca>] ? page_is_ram+0x1a/0x40 [<c1025aff>] reserve_memtype+0xdf/0x2f0 [<c1024dc9>] set_memory_uc+0x49/0xa0 [<c19334d0>] efi_enter_virtual_mode+0x1c2/0x3aa [<c19216d4>] start_kernel+0x291/0x2f2 [<c19211c7>] ? loglevel+0x1b/0x1b [<c19210bf>] i386_start_kernel+0xbf/0xc8 The only time we can call set_memory_uc() for a memory region is when it is part of the direct kernel mapping. For the case where we ioremap a memory region we must leave it alone. This patch reimplements the fix from e8c7106280a3 ("x86, efi: Calling __pa() with an ioremap()ed address is invalid") which was reverted in e1ad783b12ec because it caused a regression on some MacBooks (they hung at boot). The regression was caused because the commit only marked EFI_RUNTIME_SERVICES_DATA as E820_RESERVED_EFI, when it should have marked all regions that have the EFI_MEMORY_RUNTIME attribute. Despite first impressions, it's not possible to use ioremap_cache() to map all cached memory regions on CONFIG_X86_64 because of the way that the memory map might be configured as detailed in the following bug report, https://bugzilla.redhat.com/show_bug.cgi?id=748516 e.g. some of the EFI memory regions *need* to be mapped as part of the direct kernel mapping. Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: Matthew Garrett <mjg@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Huang Ying <huang.ying.caritas@gmail.com> Cc: Keith Packard <keithp@keithp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1350649546-23541-1-git-send-email-matt@console-pimps.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2011-12-12Revert "x86, efi: Calling __pa() with an ioremap()ed address is invalid"Keith Packard
This hangs my MacBook Air at boot time; I get no console messages at all. I reverted this on top of -rc5 and my machine boots again. This reverts commit e8c7106280a305e1ff2a3a8a4dfce141469fb039. Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Keith Packard <keithp@keithp.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Huang Ying <huang.ying.caritas@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1321621751-3650-1-git-send-email-matt@console Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-09x86, efi: Calling __pa() with an ioremap()ed address is invalidMatt Fleming
If we encounter an efi_memory_desc_t without EFI_MEMORY_WB set in ->attribute we currently call set_memory_uc(), which in turn calls __pa() on a potentially ioremap'd address. On CONFIG_X86_32 this is invalid, resulting in the following oops on some machines: BUG: unable to handle kernel paging request at f7f22280 IP: [<c10257b9>] reserve_ram_pages_type+0x89/0x210 [...] Call Trace: [<c104f8ca>] ? page_is_ram+0x1a/0x40 [<c1025aff>] reserve_memtype+0xdf/0x2f0 [<c1024dc9>] set_memory_uc+0x49/0xa0 [<c19334d0>] efi_enter_virtual_mode+0x1c2/0x3aa [<c19216d4>] start_kernel+0x291/0x2f2 [<c19211c7>] ? loglevel+0x1b/0x1b [<c19210bf>] i386_start_kernel+0xbf/0xc8 A better approach to this problem is to map the memory region with the correct attributes from the start, instead of modifying it after the fact. The uncached case can be handled by ioremap_nocache() and the cached by ioremap_cache(). Despite first impressions, it's not possible to use ioremap_cache() to map all cached memory regions on CONFIG_X86_64 because EFI_RUNTIME_SERVICES_DATA regions really don't like being mapped into the vmalloc space, as detailed in the following bug report, https://bugzilla.redhat.com/show_bug.cgi?id=748516 Therefore, we need to ensure that any EFI_RUNTIME_SERVICES_DATA regions are covered by the direct kernel mapping table on CONFIG_X86_64. To accomplish this we now map E820_RESERVED_EFI regions via the direct kernel mapping with the initial call to init_memory_mapping() in setup_arch(), whereas previously these regions wouldn't be mapped if they were after the last E820_RAM region until efi_ioremap() was called. Doing it this way allows us to delete efi_ioremap() completely. Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Huang Ying <huang.ying.caritas@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1321621751-3650-1-git-send-email-matt@console-pimps.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-25x86, efi: Retain boot service code until after switching to virtual modeMatthew Garrett
UEFI stands for "Unified Extensible Firmware Interface", where "Firmware" is an ancient African word meaning "Why do something right when you can do it so wrong that children will weep and brave adults will cower before you", and "UEI" is Celtic for "We missed DOS so we burned it into your ROMs". The UEFI specification provides for runtime services (ie, another way for the operating system to be forced to depend on the firmware) and we rely on these for certain trivial tasks such as setting up the bootloader. But some hardware fails to work if we attempt to use these runtime services from physical mode, and so we have to switch into virtual mode. So far so dreadful. The specification makes it clear that the operating system is free to do whatever it wants with boot services code after ExitBootServices() has been called. SetVirtualAddressMap() can't be called until ExitBootServices() has been. So, obviously, a whole bunch of EFI implementations call into boot services code when we do that. Since we've been charmingly naive and trusted that the specification may be somehow relevant to the real world, we've already stuffed a picture of a penguin or something in that address space. And just to make things more entertaining, we've also marked it non-executable. This patch allocates the boot services regions during EFI init and makes sure that they're executable. Then, after SetVirtualAddressMap(), it discards them and everyone lives happily ever after. Except for the ones who have to work on EFI, who live sad lives haunted by the knowledge that someone's eventually going to write yet another firmware specification. [ hpa: adding this to urgent with a stable tag since it fixes currently-broken hardware. However, I do not know what the dependencies are and so I do not know which -stable versions this may be a candidate for. ] Signed-off-by: Matthew Garrett <mjg@redhat.com> Link: http://lkml.kernel.org/r/1306331593-28715-1-git-send-email-mjg@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: <stable@kernel.org>
2011-05-09x86, efi: Ensure that the entirity of a region is mappedMatthew Garrett
It's possible for init_memory_mapping() to fail to map the entire region if it crosses a boundary, so ensure that we complete the mapping. Signed-off-by: Matthew Garrett <mjg@redhat.com> Link: http://lkml.kernel.org/r/1304623186-18261-5-git-send-email-mjg@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-09x86, efi: Consolidate EFI nx controlMatthew Garrett
The core EFI code and 64-bit EFI code currently have independent implementations of code for setting memory regions as executable or not. Let's consolidate them. Signed-off-by: Matthew Garrett <mjg@redhat.com> Link: http://lkml.kernel.org/r/1304623186-18261-2-git-send-email-mjg@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-27x86: Move efi to platformThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Huang Ying <ying.huang@intel.com>