Commits
Andy Lutomirski committed 5bc653b7318
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>