On Tue, Jan 03, 2017 at 06:48:43PM -0800, Dan Williams wrote: > On Fri, Sep 9, 2016 at 8:18 AM, Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> wrote: > > Today, it is not possible for drivers to reserve EFI boot services for > > access after efi_free_boot_services() has been called on x86. For > > ARM/arm64 it can be done simply by calling memblock_reserve(). > > > > Having this ability for all three architectures is desirable for a > > couple of reasons, > > > > 1) It saves drivers copying data out of those regions > > 2) kexec reboot can now make use of things like ESRT > > > > Instead of using the standard memblock_reserve() which is insufficient > > to reserve the region on x86 (see efi_reserve_boot_services()), a new > > API is introduced in this patch; efi_mem_reserve(). > > > > efi.memmap now always represents which EFI memory regions are > > available. On x86 the EFI boot services regions that have not been > > reserved via efi_mem_reserve() will be removed from efi.memmap during > > efi_free_boot_services(). > > > > This has implications for kexec, since it is not possible for a newly > > kexec'd kernel to access the same boot services regions that the > > initial boot kernel had access to unless they are reserved by every > > kexec kernel in the chain. > > > > Tested-by: Dave Young <dyoung@xxxxxxxxxx> [kexec/kdump] > > Tested-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> [arm] > > Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> > > Cc: Leif Lindholm <leif.lindholm@xxxxxxxxxx> > > Cc: Peter Jones <pjones@xxxxxxxxxx> > > Cc: Borislav Petkov <bp@xxxxxxxxx> > > Cc: Mark Rutland <mark.rutland@xxxxxxx> > > Signed-off-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> > > This commit appears to cause a boot regression between v4.8 and v4.9. Can you verify that the memory map looks reasonable? This looks similar (but not identical) to the traceback I was hitting on some ThinkPads with ESRT last month, so there's some chance, if it is caused by bad memory map entries, it may be fixed by 1cb209f63 on efi/next . > > BUG: unable to handle kernel paging request at ffff8830281bf1c8 > IP: [<ffffffff81a21266>] __next_mem_range_rev+0x13a/0x1d6 > PGD 3193067 PUD 3196067 PTE 80000030281bf060 > Oops: 0000 1 SMP DEBUG_PAGEALLOC > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0+ #2 > task: ffffffff82011540 task.stack: ffffffff82000000 > RIP: 0010:[<ffffffff81a21266>] [<ffffffff81a21266>] > __next_mem_range_rev+0x13a/0x1d6 > RSP: 0000:ffffffff82003dd8 EFLAGS: 00010202 > RAX: ffff8830281bf1e0 RBX: ffffffff82003e60 RCX: ffffffff82167490 > RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000001840000000 > RBP: ffffffff82003e18 R08: ffffffff821674b0 R09: 000000000000008f > R10: 000000000000008f R11: ffffffff82011cf0 R12: 0000000000000004 > R13: 0000003040000000 R14: 0000000000000000 R15: 0000000000000001 > FS: 0000000000000000(0000) GS:ffff8817e0800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffff8830281bf1c8 CR3: 000000000200a000 CR4: 00000000007406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > PKRU: 00000000 > Stack: > ffffea0000001700 ffffffff82003e50 0000000000000000 > 00000000000010000000003040000000 ffffffff82003e58 0000000000000180 > ffffffffffffffc0 > ffffffff82003e98 ffffffff81a21395 ffffffff82003e58 0000000000000000 > Call Trace: > [<ffffffff81a21395>] memblock_find_in_range_node+0x93/0x13a > [<ffffffff8221e3b1>] memblock_alloc_range_nid+0x1b/0x3e > [<ffffffff8221e5b9>] __memblock_alloc_base+0x15/0x17 > [<ffffffff8221e5cd>] memblock_alloc_base+0x12/0x2e > [<ffffffff8221e5f4>] memblock_alloc+0xb/0xd > [<ffffffff82208e22>] efi_free_boot_services+0x46/0x180 > [<ffffffff821e818b>] start_kernel+0x4a1/0x4cc > [<ffffffff821e7ad8>] ? set_init_arg+0x55/0x55 > [<ffffffff821e7120>] ? early_idt_handler_array+0x120/0x120 > [<ffffffff821e75d6>] x86_64_start_reservations+0x2a/0x2c > [<ffffffff821e7724>] x86_64_start_kernel+0x14c/0x16f > Code: 18 44 89 38 41 8d 44 24 ff 49 c1 e1 20 4c 09 c8 48 89 03 e9 a0 > 00 00 00 4d 63 d1 4c 89 d0 48 c1 e0 05 49 03 40 18 45 85 c9 74 28 <48> > 8b 50 e8 48 03 50 e0 49 83 cb ff 4d 3b 10 73 03 4c 8b 18 49 ^M > RIP [<ffffffff81a21266>] __next_mem_range_rev+0x13a/0x1d6 > > I also see that Petr may have run into it as well [1]? Petr is this > the same signature you are seeing? Can you post a boot log with > "efi=debug" on the kernel command line? > > It also fails on 4.10-rc2. However, if I revert the following commits > it boots fine: > > 4bc9f92e64c8 x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data > 8e80632fb23f efi/esrt: Use efi_mem_reserve() and avoid a kmalloc() > 816e76129ed5 efi: Allow drivers to reserve boot services forever > > [1]: https://lkml.org/lkml/2016/12/21/197 -- Peter -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
