hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

x86/efi: Allocate a trampoline if needed in efi_free_boot_services() 

On my Dell XPS 13 9350 with firmware 1.4.4 and SGX on, if I boot
Fedora 24's grub2-efi off a hard disk, my first 1MB of RAM looks
like:

 efi: mem00: [Runtime Data       |RUN|  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000000fff] (0MB)
 efi: mem01: [Boot Data          |   |  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000027fff] (0MB)
 efi: mem02: [Loader Data        |   |  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000028000-0x0000000000029fff] (0MB)
 efi: mem03: [Reserved           |   |  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x000000000002a000-0x000000000002bfff] (0MB)
 efi: mem04: [Runtime Data       |RUN|  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x000000000002c000-0x000000000002cfff] (0MB)
 efi: mem05: [Loader Data        |   |  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x000000000002d000-0x000000000002dfff] (0MB)
 efi: mem06: [Conventional Memory|   |  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x000000000002e000-0x0000000000057fff] (0MB)
 efi: mem07: [Reserved           |   |  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000058000-0x0000000000058fff] (0MB)
 efi: mem08: [Conventional Memory|   |  |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000000059000-0x000000000009ffff] (0MB)

My EBDA is at 0x2c000, which blocks off everything from 0x2c000 and
up, and my trampoline is 0x6000 bytes (6 pages), so it doesn't fit
in the loader data range at 0x28000.

Without this patch, it panics due to a failure to allocate the
trampoline.  With this patch, it works:

 [  +0.001744] Base memory trampoline at [ffff880000001000] 1000 size 24576

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Matt Fleming <mfleming@suse.de>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/998c77b3bf709f3dfed85cb30701ed1a5d8a438b.1470821230.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2016-08-10 02:29:17 -07:00 committed by Ingo Molnar
parent 5ff3e2c3c3
commit 5bc653b731
1 changed files with 21 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
arch/x86/platform/efi/quirks.c
View File

@ -254,6 +254,7 @@ void __init efi_free_boot_services(void)
for_each_efi_memory_desc(md) {
unsigned long long start = md->phys_addr;
unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
size_t rm_size;
if (md->type != EFI_BOOT_SERVICES_CODE &&
md->type != EFI_BOOT_SERVICES_DATA)
@ -263,6 +264,26 @@ void __init efi_free_boot_services(void)
if (md->attribute & EFI_MEMORY_RUNTIME)
continue;
/*
* Nasty quirk: if all sub-1MB memory is used for boot
* services, we can get here without having allocated the
* real mode trampoline. It's too late to hand boot services
* memory back to the memblock allocator, so instead
* try to manually allocate the trampoline if needed.
*
* I've seen this on a Dell XPS 13 9350 with firmware
* 1.4.4 with SGX enabled booting Linux via Fedora 24's
* grub2-efi on a hard disk. (And no, I don't know why
* this happened, but Linux should still try to boot rather
* panicing early.)
*/
rm_size = real_mode_size_needed();
if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
set_real_mode_mem(start, rm_size);
start += rm_size;
size -= rm_size;
}
free_bootmem_late(start, size);
}