On Tue, 5 Feb 2019 at 19:07, Ghannam, Yazen <Yazen.Ghannam@xxxxxxx> wrote: > > > -----Original Message----- > > From: linux-kernel-owner@xxxxxxxxxxxxxxx <linux-kernel- > > owner@xxxxxxxxxxxxxxx> On Behalf Of Ard Biesheuvel > > Sent: Saturday, February 2, 2019 3:41 AM > > To: linux-efi@xxxxxxxxxxxxxxx; Ingo Molnar <mingo@xxxxxxxxxx>; Thomas > > Gleixner <tglx@xxxxxxxxxxxxx> > > Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; > > AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>; Alexander Graf > > <agraf@xxxxxxx>; Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>; Borislav > > Petkov <bp@xxxxxxxxx>; Heinrich Schuchardt <xypron.glpk@xxxxxx>; Jeffrey > > Hugo <jhugo@xxxxxxxxxxxxxx>; Lee Jones <lee.jones@xxxxxxxxxx>; Leif > > Lindholm <leif.lindholm@xxxxxxxxxx>; Linus Torvalds <torvalds@linux- > > foundation.org>; Peter Jones <pjones@xxxxxxxxxx>; Peter Zijlstra > > <peterz@xxxxxxxxxxxxx>; Sai Praneeth Prakhya > > <sai.praneeth.prakhya@xxxxxxxxx> > > Subject: [PATCH 10/10] acpi: bgrt: parse BGRT to obtain BMP address before it > > gets clobbered > > > > The bitmap left in the framebuffer by the firmware is described by an > > ACPI table called "BGRT", which describes the size, pixel format and > > the address of a BMP image in memory. While the BGRT ACPI table is > > guaranteed to reside in a "ACPI reclaim" memory region, which is > > never touched by Linux. The BMP image, however, typically resides > > in EFI Boot Services Memory, which may have been overwritten by the > > time the BGRT discovery routine runs. > > > > So instead, drop the handling from the ACPI init code, and call the > > BGRT parsing code immediately after going over the EFI configuration > > table array, at which time no memory has been touched yet except for > > the .data/.bss regions covered by the static kernel image. > > > > Unfortunately, this involves a non-trivial amount of ACPI entry > > point and root table parsing, but we cannot rely on the normal > > ACPI infrastructure yet this early in the boot. > > > > Also note that we cannot take the 'acpi_disabled' global variable > > into account, since it may not have assumed the correct value yet > > (on arm64, the default value is '1' which is overridden to '0' if > > no DT description has been made available by the firmware) > > > > Cc: Peter Jones <pjones@xxxxxxxxxx> > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> > > --- > > Hi Ard, et. al., > > I'm trying out tip/master and I find that my system panics early during boot. Reverting > this patch seems to resolve the issue. Please see the trace below. > > I've started debugging, but I'm not familiar with this code. Please let me know if you > have any ideas or if there's anything you'd like me to try. > Hi Yazen, Thanks for the report, you are the second person to flag this issue, so in the mean time, I have asked Ingo to drop it from the efi/core queue, and so the patch will be gone from -next as soon as it refreshes. I'll cc you on the updated version of this patch once I get around to looking into it, which will probably be around early next week. Thanks, Ard. > > [ 0.000000] Kernel panic - not syncing: ERROR: Failed to allocate 0x0000000000000b40 bytes below 0x0000000000000000. > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc5-merged-bases+ #101 > [ 0.000000] Call Trace: > [ 0.000000] dump_stack+0x63/0x85 > [ 0.000000] panic+0xfe/0x2a4 > [ 0.000000] memblock_alloc_base+0x33/0x35 > [ 0.000000] memblock_phys_alloc+0x10/0x12 > [ 0.000000] efi_memmap_alloc+0x62/0x65 > [ 0.000000] efi_arch_mem_reserve+0x10e/0x194 > [ 0.000000] efi_mem_reserve+0x31/0x36 > [ 0.000000] ? efi_mem_reserve+0x31/0x36 > [ 0.000000] efi_bgrt_init+0x2c6/0x2e0 > [ 0.000000] efi_config_parse_tables+0x1b2/0x1dd > [ 0.000000] efi_config_init+0x7b/0x9f > [ 0.000000] ? efi_config_init+0x7b/0x9f > [ 0.000000] efi_init+0x366/0x465 > [ 0.000000] ? 0xffffffff87800000 > [ 0.000000] setup_arch+0x42f/0xcc9 > [ 0.000000] ? printk+0x52/0x6e > [ 0.000000] start_kernel+0x6c/0x516 > [ 0.000000] x86_64_start_reservations+0x24/0x26 > [ 0.000000] x86_64_start_kernel+0x74/0x77 > [ 0.000000] secondary_startup_64+0xa4/0xb0 > [ 0.000000] ---[ end Kernel panic - not syncing: ERROR: Failed to allocate 0x0000000000000b40 bytes below 0x0000000000000000. ]--- >
