kernel/arch/x86/platform/efi/efi-bgrt.c, branch linux-6.2.y

x86/efi/bgrt: Move efi-bgrt handling out of arch/x86

2017-04-05T10:27:24Z

Now with open-source boot firmware (EDK2) supporting ACPI BGRT table addition even for architectures like AARCH64, it makes sense to move out the 'efi-bgrt.c' file and supporting infrastructure from 'arch/x86' directory and house it inside 'drivers/firmware/efi', so that this common code can be used across architectures. Signed-off-by: Bhupesh Sharma Signed-off-by: Ard Biesheuvel Cc: Linus Torvalds Cc: Matt Fleming Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20170404160245.27812-7-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar

efi/x86: Move the EFI BGRT init code to early init code

2017-02-01T07:45:46Z

Before invoking the arch specific handler, efi_mem_reserve() reserves the given memory region through memblock. efi_bgrt_init() will call efi_mem_reserve() after mm_init(), at which time memblock is dead and should not be used anymore. The EFI BGRT code depends on ACPI initialization to get the BGRT ACPI table, so move parsing of the BGRT table to ACPI early boot code to ensure that efi_mem_reserve() in EFI BGRT code still use memblock safely. Tested-by: Bhupesh Sharma Signed-off-by: Dave Young Signed-off-by: Ard Biesheuvel Cc: Len Brown Cc: Linus Torvalds Cc: Matt Fleming Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Thomas Gleixner Cc: linux-acpi@vger.kernel.org Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1485868902-20401-9-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar

x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data

2016-09-09T15:08:38Z

efi_mem_reserve() allows us to permanently mark EFI boot services regions as reserved, which means we no longer need to copy the image data out and into a separate buffer. Leaving the data in the original boot services region has the added benefit that BGRT images can now be passed across kexec reboot. Reviewed-by: Josh Triplett Tested-by: Dave Young [kexec/kdump] Tested-by: Ard Biesheuvel [arm] Acked-by: Ard Biesheuvel Cc: Leif Lindholm Cc: Peter Jones Cc: Borislav Petkov Cc: Mark Rutland Cc: Josh Boyer Cc: Andy Lutomirski Cc: Môshe van der Sterre Signed-off-by: Matt Fleming

x86/efi-bgrt: Switch all pr_err() to pr_notice() for invalid BGRT

2016-05-04T06:36:44Z

The promise of pretty boot splashes from firmware via BGRT was at best only that; a promise. The kernel diligently checks to make sure the BGRT data firmware gives it is valid, and dutifully warns the user when it isn't. However, it does so via the pr_err log level which seems unnecessary. The user cannot do anything about this and there really isn't an error on the part of Linux to correct. This lowers the log level by using pr_notice instead. Users will no longer have their boot process uglified by the kernel reminding us that firmware can and often is broken when the 'quiet' kernel parameter is specified. Ironic, considering BGRT is supposed to make boot pretty to begin with. Signed-off-by: Josh Boyer Signed-off-by: Matt Fleming Reviewed-by: Josh Triplett Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Môshe van der Sterre Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462303781-8686-4-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar

x86/efi/bgrt: Don't ignore the BGRT if the 'valid' bit is 0

2016-02-03T10:41:19Z

Unintuitively, the BGRT graphic is apparently meant to be usable if the valid bit in not set. The valid bit only conveys uncertainty about the validity in relation to the screen state. Windows 10 actually uses the BGRT image for its boot screen even if not 'valid', for example when the user triggered the boot menu. Because it is unclear if all firmwares will provide a usable graphic in this case, we now look at the BMP magic number as an additional check. Reviewed-by: Josh Triplett Signed-off-by: Môshe van der Sterre Signed-off-by: Matt Fleming Cc: =?UTF-8?q?M=C3=B4she=20van=20der=20Sterre?= Link: http://lkml.kernel.org/r/1454364428-494-10-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar

x86/efi-bgrt: Replace early_memremap() with memremap()

2016-01-06T17:28:52Z

Môshe reported the following warning triggered on his machine since commit 50a0cb565246 ("x86/efi-bgrt: Fix kernel panic when mapping BGRT data"), [ 0.026936] ------------[ cut here ]------------ [ 0.026941] WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:137 __early_ioremap+0x102/0x1bb() [ 0.026941] Modules linked in: [ 0.026944] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1 #2 [ 0.026945] Hardware name: Dell Inc. XPS 13 9343/09K8G1, BIOS A05 07/14/2015 [ 0.026946] 0000000000000000 900f03d5a116524d ffffffff81c03e60 ffffffff813a3fff [ 0.026948] 0000000000000000 ffffffff81c03e98 ffffffff810a0852 00000000d7b76000 [ 0.026949] 0000000000000000 0000000000000001 0000000000000001 000000000000017c [ 0.026951] Call Trace: [ 0.026955] [] dump_stack+0x44/0x55 [ 0.026958] [] warn_slowpath_common+0x82/0xc0 [ 0.026959] [] warn_slowpath_null+0x1a/0x20 [ 0.026961] [] __early_ioremap+0x102/0x1bb [ 0.026962] [] early_memremap+0x13/0x15 [ 0.026964] [] efi_bgrt_init+0x162/0x1ad [ 0.026966] [] efi_late_init+0x9/0xb [ 0.026968] [] start_kernel+0x46f/0x49f [ 0.026970] [] ? early_idt_handler_array+0x120/0x120 [ 0.026972] [] x86_64_start_reservations+0x2a/0x2c [ 0.026974] [] x86_64_start_kernel+0x14a/0x16d [ 0.026977] ---[ end trace f9b3812eb8e24c58 ]--- [ 0.026978] efi_bgrt: Ignoring BGRT: failed to map image memory early_memremap() has an upper limit on the size of mapping it can handle which is ~200KB. Clearly the BGRT image on Môshe's machine is much larger than that. There's actually no reason to restrict ourselves to using the early_* version of memremap() - the ACPI BGRT driver is invoked late enough in boot that we can use the standard version, with the benefit that the late version allows mappings of arbitrary size. Reported-by: Môshe van der Sterre Tested-by: Môshe van der Sterre Signed-off-by: Matt Fleming Cc: Josh Triplett Cc: Sai Praneeth Prakhya Cc: Borislav Petkov Link: http://lkml.kernel.org/r/1450707172-12561-1-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Thomas Gleixner

x86/efi-bgrt: Fix kernel panic when mapping BGRT data

2015-12-14T15:24:24Z

Starting with this commit 35eb8b81edd4 ("x86/efi: Build our own page table structures") efi regions have a separate page directory called "efi_pgd". In order to access any efi region we have to first shift %cr3 to this page table. In the bgrt code we are trying to copy bgrt_header and image, but these regions fall under "EFI_BOOT_SERVICES_DATA" and to access these regions we have to shift %cr3 to efi_pgd and not doing so will cause page fault as shown below. [ 0.251599] Last level dTLB entries: 4KB 64, 2MB 0, 4MB 0, 1GB 4 [ 0.259126] Freeing SMP alternatives memory: 32K (ffffffff8230e000 - ffffffff82316000) [ 0.271803] BUG: unable to handle kernel paging request at fffffffefce35002 [ 0.279740] IP: [] efi_bgrt_init+0x144/0x1fd [ 0.286383] PGD 300f067 PUD 0 [ 0.289879] Oops: 0000 [#1] SMP [ 0.293566] Modules linked in: [ 0.297039] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1-eywa-eywa-built-in-47041+ #2 [ 0.306619] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B104.B01.1511110114 11/11/2015 [ 0.320925] task: ffffffff820134c0 ti: ffffffff82000000 task.ti: ffffffff82000000 [ 0.329420] RIP: 0010:[] [] efi_bgrt_init+0x144/0x1fd [ 0.338821] RSP: 0000:ffffffff82003f18 EFLAGS: 00010246 [ 0.344852] RAX: fffffffefce35000 RBX: fffffffefce35000 RCX: fffffffefce2b000 [ 0.352952] RDX: 000000008a82b000 RSI: ffffffff8235bb80 RDI: 000000008a835000 [ 0.361050] RBP: ffffffff82003f30 R08: 000000008a865000 R09: ffffffffff202850 [ 0.369149] R10: ffffffff811ad62f R11: 0000000000000000 R12: 0000000000000000 [ 0.377248] R13: ffff88016dbaea40 R14: ffffffff822622c0 R15: ffffffff82003fb0 [ 0.385348] FS: 0000000000000000(0000) GS:ffff88016d800000(0000) knlGS:0000000000000000 [ 0.394533] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.401054] CR2: fffffffefce35002 CR3: 000000000300c000 CR4: 00000000003406f0 [ 0.409153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 0.417252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 0.425350] Stack: [ 0.427638] ffffffffffffffff ffffffff82256900 ffff88016dbaea40 ffffffff82003f40 [ 0.436086] ffffffff821bbce0 ffffffff82003f88 ffffffff8219c0c2 0000000000000000 [ 0.444533] ffffffff8219ba4a ffffffff822622c0 0000000000083000 00000000ffffffff [ 0.452978] Call Trace: [ 0.455763] [] efi_late_init+0x9/0xb [ 0.461697] [] start_kernel+0x463/0x47f [ 0.467928] [] ? set_init_arg+0x55/0x55 [ 0.474159] [] ? early_idt_handler_array+0x120/0x120 [ 0.481669] [] x86_64_start_reservations+0x2a/0x2c [ 0.488982] [] x86_64_start_kernel+0x13d/0x14c [ 0.495897] Code: 00 41 b4 01 48 8b 78 28 e8 09 36 01 00 48 85 c0 48 89 c3 75 13 48 c7 c7 f8 ac d3 81 31 c0 e8 d7 3b fb fe e9 b5 00 00 00 45 84 e4 <44> 8b 6b 02 74 0d be 06 00 00 00 48 89 df e8 ae 34 0$ [ 0.518151] RIP [] efi_bgrt_init+0x144/0x1fd [ 0.524888] RSP [ 0.528851] CR2: fffffffefce35002 [ 0.532615] ---[ end trace 7b06521e6ebf2aea ]--- [ 0.537852] Kernel panic - not syncing: Attempted to kill the idle task! As said above one way to fix this bug is to shift %cr3 to efi_pgd but we are not doing that way because it leaks inner details of how we switch to EFI page tables into a new call site and it also adds duplicate code. Instead, we remove the call to efi_lookup_mapped_addr() and always perform early_mem*() instead of early_io*() because we want to remap RAM regions and not I/O regions. We also delete efi_lookup_mapped_addr() because we are no longer using it. Signed-off-by: Sai Praneeth Prakhya Reported-by: Wendy Wang Cc: Borislav Petkov Cc: Josh Triplett Cc: Ricardo Neri Cc: Ravi Shankar Signed-off-by: Matt Fleming

x86/efi: Preface all print statements with efi* tag

2015-12-14T15:24:03Z

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 Reviewed-by: Josh Triplett Signed-off-by: Matt Fleming

x86/efi-bgrt: Switch pr_err() to pr_debug() for invalid BGRT

2015-08-08T08:37:39Z

It's totally legitimate, per the ACPI spec, for the firmware to set the BGRT 'status' field to zero to indicate that the BGRT image isn't being displayed, and we shouldn't be printing an error message in that case because it's just noise for users. So swap pr_err() for pr_debug(). However, Josh points that out it still makes sense to test the validity of the upper 7 bits of the 'status' field, since they're marked as "reserved" in the spec and must be zero. If firmware violates this it really *is* an error. Reported-by: Tom Yan Tested-by: Tom Yan Signed-off-by: Matt Fleming Reviewed-by: Josh Triplett Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Matthew Garrett Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1438936621-5215-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar

x86/mm, efi: Use early_ioremap() in arch/x86/platform/efi/efi-bgrt.c

2015-02-24T14:58:07Z

Use early_ioremap() to map an I/O-area instead of early_memremap(). Signed-off-by: Juergen Gross Cc: matt.fleming@intel.com Link: http://lkml.kernel.org/r/1424769211-11378-5-git-send-email-jgross@suse.com Signed-off-by: Ingo Molnar