From: Ard Biesheuvel <ardb+git@google.com>
To: stable@vger.kernel.org
Cc: linux-efi@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Borislav Petkov <bp@alien8.de>
Subject: [PATCH stable-v6.1 08/18] efi/libstub: Add limit argument to efi_random_alloc()
Date: Mon, 4 Mar 2024 12:19:46 +0100 [thread overview]
Message-ID: <20240304111937.2556102-28-ardb+git@google.com> (raw)
In-Reply-To: <20240304111937.2556102-20-ardb+git@google.com>
From: Ard Biesheuvel <ardb@kernel.org>
[ Commit bc5ddceff4c14494d83449ad45c985e6cd353fce upstream ]
x86 will need to limit the kernel memory allocation to the lowest 512
MiB of memory, to match the behavior of the existing bare metal KASLR
physical randomization logic. So in preparation for that, add a limit
parameter to efi_random_alloc() and wire it up.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230807162720.545787-22-ardb@kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
drivers/firmware/efi/libstub/arm64-stub.c | 2 +-
drivers/firmware/efi/libstub/efistub.h | 2 +-
drivers/firmware/efi/libstub/randomalloc.c | 10 ++++++----
3 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index 40275c3131c8..16377b452119 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -181,7 +181,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
*/
status = efi_random_alloc(*reserve_size, min_kimg_align,
reserve_addr, phys_seed,
- EFI_LOADER_CODE);
+ EFI_LOADER_CODE, EFI_ALLOC_LIMIT);
if (status != EFI_SUCCESS)
efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
} else {
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 6f5a1a16db15..8a343ea1231a 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -905,7 +905,7 @@ efi_status_t efi_get_random_bytes(unsigned long size, u8 *out);
efi_status_t efi_random_alloc(unsigned long size, unsigned long align,
unsigned long *addr, unsigned long random_seed,
- int memory_type);
+ int memory_type, unsigned long alloc_limit);
efi_status_t efi_random_get_seed(void);
diff --git a/drivers/firmware/efi/libstub/randomalloc.c b/drivers/firmware/efi/libstub/randomalloc.c
index 1692d19ae80f..ed6f6087a9ea 100644
--- a/drivers/firmware/efi/libstub/randomalloc.c
+++ b/drivers/firmware/efi/libstub/randomalloc.c
@@ -16,7 +16,8 @@
*/
static unsigned long get_entry_num_slots(efi_memory_desc_t *md,
unsigned long size,
- unsigned long align_shift)
+ unsigned long align_shift,
+ u64 alloc_limit)
{
unsigned long align = 1UL << align_shift;
u64 first_slot, last_slot, region_end;
@@ -29,7 +30,7 @@ static unsigned long get_entry_num_slots(efi_memory_desc_t *md,
return 0;
region_end = min(md->phys_addr + md->num_pages * EFI_PAGE_SIZE - 1,
- (u64)EFI_ALLOC_LIMIT);
+ alloc_limit);
if (region_end < size)
return 0;
@@ -54,7 +55,8 @@ efi_status_t efi_random_alloc(unsigned long size,
unsigned long align,
unsigned long *addr,
unsigned long random_seed,
- int memory_type)
+ int memory_type,
+ unsigned long alloc_limit)
{
unsigned long total_slots = 0, target_slot;
unsigned long total_mirrored_slots = 0;
@@ -76,7 +78,7 @@ efi_status_t efi_random_alloc(unsigned long size,
efi_memory_desc_t *md = (void *)map->map + map_offset;
unsigned long slots;
- slots = get_entry_num_slots(md, size, ilog2(align));
+ slots = get_entry_num_slots(md, size, ilog2(align), alloc_limit);
MD_NUM_SLOTS(md) = slots;
total_slots += slots;
if (md->attribute & EFI_MEMORY_MORE_RELIABLE)
--
2.44.0.278.ge034bb2e1d-goog
next prev parent reply other threads:[~2024-03-04 11:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-04 11:19 [PATCH stable-v6.1 00/18] efistub/x86 changes for secure boot Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 01/18] arm64: efi: Limit allocations to 48-bit addressable physical region Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 02/18] efi: efivars: prevent double registration Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 03/18] x86/efistub: Simplify and clean up handover entry code Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 04/18] x86/decompressor: Avoid magic offsets for EFI handover entrypoint Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 05/18] x86/efistub: Clear BSS in EFI handover protocol entrypoint Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 06/18] x86/decompressor: Move global symbol references to C code Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 07/18] efi/libstub: Add memory attribute protocol definitions Ard Biesheuvel
2024-03-04 11:19 ` Ard Biesheuvel [this message]
2024-03-04 11:19 ` [PATCH stable-v6.1 09/18] x86/efistub: Perform 4/5 level paging switch from the stub Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 10/18] x86/decompressor: Factor out kernel decompression and relocation Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 11/18] x86/efistub: Prefer EFI memory attributes protocol over DXE services Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 12/18] x86/efistub: Perform SNP feature test while running in the firmware Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 13/18] x86/efistub: Avoid legacy decompressor when doing EFI boot Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 14/18] efi/x86: Avoid physical KASLR on older Dell systems Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 15/18] x86/efistub: Avoid placing the kernel below LOAD_PHYSICAL_ADDR Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 16/18] x86/boot: Rename conflicting 'boot_params' pointer to 'boot_params_ptr' Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 17/18] x86/boot: efistub: Assign global boot_params variable Ard Biesheuvel
2024-03-04 11:19 ` [PATCH stable-v6.1 18/18] efi/x86: Fix the missing KASLR_FLAG bit in boot_params->hdr.loadflags Ard Biesheuvel
2024-03-04 11:42 ` [PATCH stable-v6.1 00/18] efistub/x86 changes for secure boot Greg KH
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