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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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09503379dc
Madper reported seeing the following crash, BUG: unable to handle kernel paging request at ffffffffff340003 IP: [<ffffffff81d85ba4>] efi_bgrt_init+0x9d/0x133 Call Trace: [<ffffffff81d8525d>] efi_late_init+0x9/0xb [<ffffffff81d68f59>] start_kernel+0x436/0x450 [<ffffffff81d6892c>] ? repair_env_string+0x5c/0x5c [<ffffffff81d68120>] ? early_idt_handlers+0x120/0x120 [<ffffffff81d685de>] x86_64_start_reservations+0x2a/0x2c [<ffffffff81d6871e>] x86_64_start_kernel+0x13e/0x14d This is caused because the layout of the ACPI BGRT header on this system doesn't match the definition from the ACPI spec, and so we get a bogus physical address when dereferencing ->image_address in efi_bgrt_init(). Luckily the status field in the BGRT header clearly marks it as invalid, so we can check that field and skip BGRT initialisation. Reported-by: Madper Xie <cxie@redhat.com> Suggested-by: Toshi Kani <toshi.kani@hp.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
/*
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* Copyright 2012 Intel Corporation
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* Author: Josh Triplett <josh@joshtriplett.org>
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*
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* Based on the bgrt driver:
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* Copyright 2012 Red Hat, Inc <mjg@redhat.com>
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* Author: Matthew Garrett
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/acpi.h>
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#include <linux/efi.h>
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#include <linux/efi-bgrt.h>
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struct acpi_table_bgrt *bgrt_tab;
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void *__initdata bgrt_image;
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size_t __initdata bgrt_image_size;
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struct bmp_header {
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u16 id;
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u32 size;
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} __packed;
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void __init efi_bgrt_init(void)
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{
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acpi_status status;
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void __iomem *image;
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bool ioremapped = false;
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struct bmp_header bmp_header;
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if (acpi_disabled)
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return;
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status = acpi_get_table("BGRT", 0,
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(struct acpi_table_header **)&bgrt_tab);
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if (ACPI_FAILURE(status))
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return;
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if (bgrt_tab->header.length < sizeof(*bgrt_tab))
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return;
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if (bgrt_tab->version != 1 || bgrt_tab->status != 1)
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return;
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if (bgrt_tab->image_type != 0 || !bgrt_tab->image_address)
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return;
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image = efi_lookup_mapped_addr(bgrt_tab->image_address);
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if (!image) {
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image = early_memremap(bgrt_tab->image_address,
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sizeof(bmp_header));
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ioremapped = true;
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if (!image)
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return;
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}
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memcpy_fromio(&bmp_header, image, sizeof(bmp_header));
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if (ioremapped)
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early_iounmap(image, sizeof(bmp_header));
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bgrt_image_size = bmp_header.size;
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bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL);
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if (!bgrt_image)
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return;
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if (ioremapped) {
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image = early_memremap(bgrt_tab->image_address,
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bmp_header.size);
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if (!image) {
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kfree(bgrt_image);
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bgrt_image = NULL;
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return;
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}
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}
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memcpy_fromio(bgrt_image, image, bgrt_image_size);
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if (ioremapped)
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early_iounmap(image, bmp_header.size);
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}
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