From 0e72a6a3cfc3a32273f5e99bfaa4407f4917d343 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 15 Jan 2020 17:35:45 +0100 Subject: efi: Export boot-services code and data as debugfs-blobs Sometimes it is useful to be able to dump the efi boot-services code and data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi, but only if efi=debug is passed on the kernel-commandline as this requires not freeing those memory-regions, which costs 20+ MB of RAM. Reviewed-by: Greg Kroah-Hartman Acked-by: Ard Biesheuvel Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20200115163554.101315-2-hdegoede@redhat.com Signed-off-by: Ard Biesheuvel --- arch/x86/platform/efi/efi.c | 1 + arch/x86/platform/efi/quirks.c | 4 ++++ 2 files changed, 5 insertions(+) (limited to 'arch/x86/platform') diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index ae923ee8e2b4..8391d3c658b4 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -243,6 +243,7 @@ int __init efi_memblock_x86_reserve_range(void) efi.memmap.desc_version); memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size); + set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags); return 0; } diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index 88d32c06cffa..bada1037b711 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -410,6 +410,10 @@ void __init efi_free_boot_services(void) int num_entries = 0; void *new, *new_md; + /* Keep all regions for /sys/kernel/debug/efi */ + if (efi_enabled(EFI_DBG)) + return; + for_each_efi_memory_desc(md) { unsigned long long start = md->phys_addr; unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; -- cgit v1.2.3