* [PATCH v5 0/5] riscv: Introduce KASLR
@ 2023-07-21 7:48 Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 1/5] riscv: Introduce virtual kernel mapping KASLR Alexandre Ghiti
` (4 more replies)
0 siblings, 5 replies; 12+ messages in thread
From: Alexandre Ghiti @ 2023-07-21 7:48 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Ard Biesheuvel,
Kees Cook, linux-riscv, linux-kernel, linux-efi, linux-arm-kernel
Cc: Alexandre Ghiti
The following KASLR implementation allows to randomize the kernel mapping:
- virtually: we expect the bootloader to provide a seed in the device-tree
- physically: only implemented in the EFI stub, it relies on the firmware to
provide a seed using EFI_RNG_PROTOCOL. arm64 has a similar implementation
hence the patch 3 factorizes KASLR related functions for riscv to take
advantage.
The new virtual kernel location is limited by the early page table that only
has one PUD and with the PMD alignment constraint, the kernel can only take
< 512 positions.
base-commit-tag: v6.5-rc1
Changes in v5:
* Renamed efi-stub-kaslr.c into kaslr.c and fix commit log of patch 3,
as suggested by Ard
* Removed stubs since the kaslr functions were moved to their own file
(and then does not trigger any build failure for architectures that do
not call those functions since they are in their own compilation unit)
Changes in v4:
* Fix efi_get_kimg macro that returned nothing
* Moved new kaslr functions into their own files to avoid zboot link
failures, as suggested by Ard
Changes in v3:
* Rebase on top of 6.4-rc2
* Make RANDOMIZE_BASE depend on 64bit
* Fix efi_icache_sync and efi_get_kimg_min_align which were undefined
in x86 (and certainly other archs)
* Add patch 4 to fix warning on rv32
Changes in v2:
* Rebase on top of 6.3-rc1
* Add a riscv cache sync after memcpying the kernel
* Add kaslr_offset implementation for KCOV
* Add forward declaration to quiet LLVM
Alexandre Ghiti (5):
riscv: Introduce virtual kernel mapping KASLR
riscv: Dump out kernel offset information on panic
arm64: libstub: Move KASLR handling functions to kaslr.c
libstub: Fix compilation warning for rv32
riscv: libstub: Implement KASLR by using generic functions
arch/arm64/include/asm/efi.h | 2 +
arch/riscv/Kconfig | 19 +++
arch/riscv/include/asm/efi.h | 2 +
arch/riscv/include/asm/page.h | 3 +
arch/riscv/kernel/image-vars.h | 1 +
arch/riscv/kernel/pi/Makefile | 2 +-
arch/riscv/kernel/pi/cmdline_early.c | 13 ++
arch/riscv/kernel/pi/fdt_early.c | 30 ++++
arch/riscv/kernel/setup.c | 25 ++++
arch/riscv/mm/init.c | 36 ++++-
drivers/firmware/efi/libstub/Makefile | 3 +-
drivers/firmware/efi/libstub/arm64-stub.c | 117 ++--------------
drivers/firmware/efi/libstub/efistub.h | 8 ++
drivers/firmware/efi/libstub/kaslr.c | 159 ++++++++++++++++++++++
drivers/firmware/efi/libstub/riscv-stub.c | 33 ++---
15 files changed, 328 insertions(+), 125 deletions(-)
create mode 100644 arch/riscv/kernel/pi/fdt_early.c
create mode 100644 drivers/firmware/efi/libstub/kaslr.c
--
2.39.2
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http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v5 1/5] riscv: Introduce virtual kernel mapping KASLR
2023-07-21 7:48 [PATCH v5 0/5] riscv: Introduce KASLR Alexandre Ghiti
@ 2023-07-21 7:48 ` Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 2/5] riscv: Dump out kernel offset information on panic Alexandre Ghiti
` (3 subsequent siblings)
4 siblings, 0 replies; 12+ messages in thread
From: Alexandre Ghiti @ 2023-07-21 7:48 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Ard Biesheuvel,
Kees Cook, linux-riscv, linux-kernel, linux-efi, linux-arm-kernel
Cc: Alexandre Ghiti
KASLR implementation relies on a relocatable kernel so that we can move
the kernel mapping.
The seed needed to virtually move the kernel is taken from the device tree,
so we rely on the bootloader to provide a correct seed. Zkr could be used
unconditionnally instead if implemented, but that's for another patch.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
arch/riscv/Kconfig | 19 +++++++++++++++
arch/riscv/include/asm/page.h | 3 +++
arch/riscv/kernel/pi/Makefile | 2 +-
arch/riscv/kernel/pi/cmdline_early.c | 13 ++++++++++
arch/riscv/kernel/pi/fdt_early.c | 30 +++++++++++++++++++++++
arch/riscv/mm/init.c | 36 +++++++++++++++++++++++++++-
6 files changed, 101 insertions(+), 2 deletions(-)
create mode 100644 arch/riscv/kernel/pi/fdt_early.c
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 4c07b9189c86..6a606d5b74c6 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -719,6 +719,25 @@ config RELOCATABLE
If unsure, say N.
+config RANDOMIZE_BASE
+ bool "Randomize the address of the kernel image"
+ select RELOCATABLE
+ depends on MMU && 64BIT && !XIP_KERNEL
+ help
+ Randomizes the virtual address at which the kernel image is
+ loaded, as a security feature that deters exploit attempts
+ relying on knowledge of the location of kernel internals.
+
+ It is the bootloader's job to provide entropy, by passing a
+ random u64 value in /chosen/kaslr-seed at kernel entry.
+
+ When booting via the UEFI stub, it will invoke the firmware's
+ EFI_RNG_PROTOCOL implementation (if available) to supply entropy
+ to the kernel proper. In addition, it will randomise the physical
+ location of the kernel Image as well.
+
+ If unsure, say N.
+
endmenu # "Kernel features"
menu "Boot options"
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index b55ba20903ec..5488ecc337b6 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -106,6 +106,7 @@ typedef struct page *pgtable_t;
struct kernel_mapping {
unsigned long page_offset;
unsigned long virt_addr;
+ unsigned long virt_offset;
uintptr_t phys_addr;
uintptr_t size;
/* Offset between linear mapping virtual address and kernel load address */
@@ -185,6 +186,8 @@ extern phys_addr_t __phys_addr_symbol(unsigned long x);
#define sym_to_pfn(x) __phys_to_pfn(__pa_symbol(x))
+unsigned long kaslr_offset(void);
+
#endif /* __ASSEMBLY__ */
#define virt_addr_valid(vaddr) ({ \
diff --git a/arch/riscv/kernel/pi/Makefile b/arch/riscv/kernel/pi/Makefile
index 7b593d44c712..07915dc9279e 100644
--- a/arch/riscv/kernel/pi/Makefile
+++ b/arch/riscv/kernel/pi/Makefile
@@ -35,5 +35,5 @@ $(obj)/string.o: $(srctree)/lib/string.c FORCE
$(obj)/ctype.o: $(srctree)/lib/ctype.c FORCE
$(call if_changed_rule,cc_o_c)
-obj-y := cmdline_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o
+obj-y := cmdline_early.pi.o fdt_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o
extra-y := $(patsubst %.pi.o,%.o,$(obj-y))
diff --git a/arch/riscv/kernel/pi/cmdline_early.c b/arch/riscv/kernel/pi/cmdline_early.c
index 05652d13c746..68e786c84c94 100644
--- a/arch/riscv/kernel/pi/cmdline_early.c
+++ b/arch/riscv/kernel/pi/cmdline_early.c
@@ -14,6 +14,7 @@ static char early_cmdline[COMMAND_LINE_SIZE];
* LLVM complain because the function is actually unused in this file).
*/
u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa);
+bool set_nokaslr_from_cmdline(uintptr_t dtb_pa);
static char *get_early_cmdline(uintptr_t dtb_pa)
{
@@ -60,3 +61,15 @@ u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa)
return match_noXlvl(cmdline);
}
+
+static bool match_nokaslr(char *cmdline)
+{
+ return strstr(cmdline, "nokaslr");
+}
+
+bool set_nokaslr_from_cmdline(uintptr_t dtb_pa)
+{
+ char *cmdline = get_early_cmdline(dtb_pa);
+
+ return match_nokaslr(cmdline);
+}
diff --git a/arch/riscv/kernel/pi/fdt_early.c b/arch/riscv/kernel/pi/fdt_early.c
new file mode 100644
index 000000000000..899610e042ab
--- /dev/null
+++ b/arch/riscv/kernel/pi/fdt_early.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/libfdt.h>
+
+/*
+ * Declare the functions that are exported (but prefixed) here so that LLVM
+ * does not complain it lacks the 'static' keyword (which, if added, makes
+ * LLVM complain because the function is actually unused in this file).
+ */
+u64 get_kaslr_seed(uintptr_t dtb_pa);
+
+u64 get_kaslr_seed(uintptr_t dtb_pa)
+{
+ int node, len;
+ fdt64_t *prop;
+ u64 ret;
+
+ node = fdt_path_offset((void *)dtb_pa, "/chosen");
+ if (node < 0)
+ return 0;
+
+ prop = fdt_getprop_w((void *)dtb_pa, node, "kaslr-seed", &len);
+ if (!prop || len != sizeof(u64))
+ return 0;
+
+ ret = fdt64_to_cpu(*prop);
+ *prop = 0;
+ return ret;
+}
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 70fb31960b63..ff926531236e 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1012,11 +1012,45 @@ static void __init pt_ops_set_late(void)
#endif
}
+#ifdef CONFIG_RANDOMIZE_BASE
+extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa);
+extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa);
+
+static int __init print_nokaslr(char *p)
+{
+ pr_info("Disabled KASLR");
+ return 0;
+}
+early_param("nokaslr", print_nokaslr);
+
+unsigned long kaslr_offset(void)
+{
+ return kernel_map.virt_offset;
+}
+#endif
+
asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{
pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
- kernel_map.virt_addr = KERNEL_LINK_ADDR;
+#ifdef CONFIG_RANDOMIZE_BASE
+ if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) {
+ u64 kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
+ u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
+ u32 nr_pos;
+
+ /*
+ * Compute the number of positions available: we are limited
+ * by the early page table that only has one PUD and we must
+ * be aligned on PMD_SIZE.
+ */
+ nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE;
+
+ kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE;
+ }
+#endif
+
+ kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset;
kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
#ifdef CONFIG_XIP_KERNEL
--
2.39.2
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v5 2/5] riscv: Dump out kernel offset information on panic
2023-07-21 7:48 [PATCH v5 0/5] riscv: Introduce KASLR Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 1/5] riscv: Introduce virtual kernel mapping KASLR Alexandre Ghiti
@ 2023-07-21 7:48 ` Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c Alexandre Ghiti
` (2 subsequent siblings)
4 siblings, 0 replies; 12+ messages in thread
From: Alexandre Ghiti @ 2023-07-21 7:48 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Ard Biesheuvel,
Kees Cook, linux-riscv, linux-kernel, linux-efi, linux-arm-kernel
Cc: Alexandre Ghiti, Zong Li
Dump out the KASLR virtual kernel offset when panic to help debug kernel.
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
arch/riscv/kernel/setup.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 971fe776e2f8..0fb5a26ca4cc 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -21,6 +21,7 @@
#include <linux/smp.h>
#include <linux/efi.h>
#include <linux/crash_dump.h>
+#include <linux/panic_notifier.h>
#include <asm/acpi.h>
#include <asm/alternative.h>
@@ -341,3 +342,27 @@ void free_initmem(void)
free_initmem_default(POISON_FREE_INITMEM);
}
+
+static int dump_kernel_offset(struct notifier_block *self,
+ unsigned long v, void *p)
+{
+ pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
+ kernel_map.virt_offset,
+ KERNEL_LINK_ADDR);
+
+ return 0;
+}
+
+static struct notifier_block kernel_offset_notifier = {
+ .notifier_call = dump_kernel_offset
+};
+
+static int __init register_kernel_offset_dumper(void)
+{
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &kernel_offset_notifier);
+
+ return 0;
+}
+device_initcall(register_kernel_offset_dumper);
--
2.39.2
_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
2023-07-21 7:48 [PATCH v5 0/5] riscv: Introduce KASLR Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 1/5] riscv: Introduce virtual kernel mapping KASLR Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 2/5] riscv: Dump out kernel offset information on panic Alexandre Ghiti
@ 2023-07-21 7:48 ` Alexandre Ghiti
2023-07-21 14:41 ` Ard Biesheuvel
` (3 more replies)
2023-07-21 7:48 ` [PATCH v5 4/5] libstub: Fix compilation warning for rv32 Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 5/5] riscv: libstub: Implement KASLR by using generic functions Alexandre Ghiti
4 siblings, 4 replies; 12+ messages in thread
From: Alexandre Ghiti @ 2023-07-21 7:48 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Ard Biesheuvel,
Kees Cook, linux-riscv, linux-kernel, linux-efi, linux-arm-kernel
Cc: Alexandre Ghiti
This prepares for riscv to use the same functions to handle the pĥysical
kernel move when KASLR is enabled.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
arch/arm64/include/asm/efi.h | 2 +
drivers/firmware/efi/libstub/Makefile | 3 +-
drivers/firmware/efi/libstub/arm64-stub.c | 117 ++--------------
drivers/firmware/efi/libstub/efistub.h | 8 ++
drivers/firmware/efi/libstub/kaslr.c | 159 ++++++++++++++++++++++
5 files changed, 184 insertions(+), 105 deletions(-)
create mode 100644 drivers/firmware/efi/libstub/kaslr.c
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 4cf2cb053bc8..46273ee89445 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -168,4 +168,6 @@ static inline void efi_capsule_flush_cache_range(void *addr, int size)
efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f);
+void efi_icache_sync(unsigned long start, unsigned long end);
+
#endif /* _ASM_EFI_H */
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 16d64a34d1e1..d363c806e87d 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -67,7 +67,8 @@ OBJECT_FILES_NON_STANDARD := y
# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
KCOV_INSTRUMENT := n
-lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \
+lib-y := efi-stub-helper.o kaslr.o \
+ gop.o secureboot.o tpm.o \
file.o mem.o random.o randomalloc.o pci.o \
skip_spaces.o lib-cmdline.o lib-ctype.o \
alignedmem.o relocate.o printk.o vsprintf.o
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index 770b8ecb7398..452b7ccd330e 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -14,42 +14,6 @@
#include "efistub.h"
-/*
- * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
- * to provide space, and fail to zero it). Check for this condition by double
- * checking that the first and the last byte of the image are covered by the
- * same EFI memory map entry.
- */
-static bool check_image_region(u64 base, u64 size)
-{
- struct efi_boot_memmap *map;
- efi_status_t status;
- bool ret = false;
- int map_offset;
-
- status = efi_get_memory_map(&map, false);
- if (status != EFI_SUCCESS)
- return false;
-
- for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) {
- efi_memory_desc_t *md = (void *)map->map + map_offset;
- u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
-
- /*
- * Find the region that covers base, and return whether
- * it covers base+size bytes.
- */
- if (base >= md->phys_addr && base < end) {
- ret = (base + size) <= end;
- break;
- }
- }
-
- efi_bs_call(free_pool, map);
-
- return ret;
-}
-
efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
@@ -59,31 +23,6 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
{
efi_status_t status;
unsigned long kernel_size, kernel_codesize, kernel_memsize;
- u32 phys_seed = 0;
- u64 min_kimg_align = efi_get_kimg_min_align();
-
- if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
- efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
- void *p;
-
- if (efi_nokaslr) {
- efi_info("KASLR disabled on kernel command line\n");
- } else if (efi_bs_call(handle_protocol, image_handle,
- &li_fixed_proto, &p) == EFI_SUCCESS) {
- efi_info("Image placement fixed by loader\n");
- } else {
- status = efi_get_random_bytes(sizeof(phys_seed),
- (u8 *)&phys_seed);
- if (status == EFI_NOT_FOUND) {
- efi_info("EFI_RNG_PROTOCOL unavailable\n");
- efi_nokaslr = true;
- } else if (status != EFI_SUCCESS) {
- efi_err("efi_get_random_bytes() failed (0x%lx)\n",
- status);
- efi_nokaslr = true;
- }
- }
- }
if (image->image_base != _text) {
efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
@@ -98,50 +37,15 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
kernel_codesize = __inittext_end - _text;
kernel_memsize = kernel_size + (_end - _edata);
*reserve_size = kernel_memsize;
+ *image_addr = (unsigned long)_text;
- if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
- /*
- * If KASLR is enabled, and we have some randomness available,
- * locate the kernel at a randomized offset in physical memory.
- */
- status = efi_random_alloc(*reserve_size, min_kimg_align,
- reserve_addr, phys_seed,
- EFI_LOADER_CODE);
- if (status != EFI_SUCCESS)
- efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
- } else {
- status = EFI_OUT_OF_RESOURCES;
- }
-
- if (status != EFI_SUCCESS) {
- if (!check_image_region((u64)_text, kernel_memsize)) {
- efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
- } else if (IS_ALIGNED((u64)_text, min_kimg_align) &&
- (u64)_end < EFI_ALLOC_LIMIT) {
- /*
- * Just execute from wherever we were loaded by the
- * UEFI PE/COFF loader if the placement is suitable.
- */
- *image_addr = (u64)_text;
- *reserve_size = 0;
- return EFI_SUCCESS;
- }
-
- status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
- ULONG_MAX, min_kimg_align,
- EFI_LOADER_CODE);
-
- if (status != EFI_SUCCESS) {
- efi_err("Failed to relocate kernel\n");
- *reserve_size = 0;
- return status;
- }
- }
-
- *image_addr = *reserve_addr;
- memcpy((void *)*image_addr, _text, kernel_size);
- caches_clean_inval_pou(*image_addr, *image_addr + kernel_codesize);
- efi_remap_image(*image_addr, *reserve_size, kernel_codesize);
+ status = efi_kaslr_relocate_kernel(image_addr,
+ reserve_addr, reserve_size,
+ kernel_size, kernel_codesize,
+ kernel_memsize,
+ efi_kaslr_get_phys_seed(image_handle));
+ if (status != EFI_SUCCESS)
+ return status;
return EFI_SUCCESS;
}
@@ -159,3 +63,8 @@ unsigned long primary_entry_offset(void)
*/
return (char *)primary_entry - _text;
}
+
+void efi_icache_sync(unsigned long start, unsigned long end)
+{
+ caches_clean_inval_pou(start, end);
+}
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 6aa38a1bf126..b1a1037567ba 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -1132,6 +1132,14 @@ const u8 *__efi_get_smbios_string(const struct efi_smbios_record *record,
void efi_remap_image(unsigned long image_base, unsigned alloc_size,
unsigned long code_size);
+efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long kernel_size,
+ unsigned long kernel_codesize,
+ unsigned long kernel_memsize,
+ u32 phys_seed);
+u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle);
asmlinkage efi_status_t __efiapi
efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab);
diff --git a/drivers/firmware/efi/libstub/kaslr.c b/drivers/firmware/efi/libstub/kaslr.c
new file mode 100644
index 000000000000..be0c8ab0982a
--- /dev/null
+++ b/drivers/firmware/efi/libstub/kaslr.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helper functions used by the EFI stub on multiple
+ * architectures to deal with physical address space randomization.
+ */
+#include <linux/efi.h>
+
+#include "efistub.h"
+
+/**
+ * efi_kaslr_get_phys_seed() - Get random seed for physical kernel KASLR
+ * @image_handle: Handle to the image
+ *
+ * If KASLR is not disabled, obtain a random seed using EFI_RNG_PROTOCOL
+ * that will be used to move the kernel physical mapping.
+ *
+ * Return: the random seed
+ */
+u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle)
+{
+ efi_status_t status;
+ u32 phys_seed;
+ efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
+ void *p;
+
+ if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
+ return 0;
+
+ if (efi_nokaslr) {
+ efi_info("KASLR disabled on kernel command line\n");
+ } else if (efi_bs_call(handle_protocol, image_handle,
+ &li_fixed_proto, &p) == EFI_SUCCESS) {
+ efi_info("Image placement fixed by loader\n");
+ } else {
+ status = efi_get_random_bytes(sizeof(phys_seed),
+ (u8 *)&phys_seed);
+ if (status == EFI_SUCCESS) {
+ return phys_seed;
+ } else if (status == EFI_NOT_FOUND) {
+ efi_info("EFI_RNG_PROTOCOL unavailable\n");
+ efi_nokaslr = true;
+ } else if (status != EFI_SUCCESS) {
+ efi_err("efi_get_random_bytes() failed (0x%lx)\n",
+ status);
+ efi_nokaslr = true;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
+ * to provide space, and fail to zero it). Check for this condition by double
+ * checking that the first and the last byte of the image are covered by the
+ * same EFI memory map entry.
+ */
+static bool check_image_region(u64 base, u64 size)
+{
+ struct efi_boot_memmap *map;
+ efi_status_t status;
+ bool ret = false;
+ int map_offset;
+
+ status = efi_get_memory_map(&map, false);
+ if (status != EFI_SUCCESS)
+ return false;
+
+ for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) {
+ efi_memory_desc_t *md = (void *)map->map + map_offset;
+ u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
+
+ /*
+ * Find the region that covers base, and return whether
+ * it covers base+size bytes.
+ */
+ if (base >= md->phys_addr && base < end) {
+ ret = (base + size) <= end;
+ break;
+ }
+ }
+
+ efi_bs_call(free_pool, map);
+
+ return ret;
+}
+
+/**
+ * efi_kaslr_relocate_kernel() - Relocate the kernel (random if KASLR enabled)
+ * @image_addr: Pointer to the current kernel location
+ * @reserve_addr: Pointer to the relocated kernel location
+ * @reserve_size: Size of the relocated kernel
+ * @kernel_size: Size of the text + data
+ * @kernel_codesize: Size of the text
+ * @kernel_memsize: Size of the text + data + bss
+ * @phys_seed: Random seed used for the relocation
+ *
+ * If KASLR is not enabled, this function relocates the kernel to a fixed
+ * address (or leave it as its current location). If KASLR is enabled, the
+ * kernel physical location is randomized using the seed in parameter.
+ *
+ * Return: status code, EFI_SUCCESS if relocation is successful
+ */
+efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long kernel_size,
+ unsigned long kernel_codesize,
+ unsigned long kernel_memsize,
+ u32 phys_seed)
+{
+ efi_status_t status;
+ u64 min_kimg_align = efi_get_kimg_min_align();
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
+ /*
+ * If KASLR is enabled, and we have some randomness available,
+ * locate the kernel at a randomized offset in physical memory.
+ */
+ status = efi_random_alloc(*reserve_size, min_kimg_align,
+ reserve_addr, phys_seed,
+ EFI_LOADER_CODE);
+ if (status != EFI_SUCCESS)
+ efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
+ } else {
+ status = EFI_OUT_OF_RESOURCES;
+ }
+
+ if (status != EFI_SUCCESS) {
+ if (!check_image_region(*image_addr, kernel_memsize)) {
+ efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
+ } else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
+ (u64)_end < EFI_ALLOC_LIMIT) {
+ /*
+ * Just execute from wherever we were loaded by the
+ * UEFI PE/COFF loader if the placement is suitable.
+ */
+ *reserve_size = 0;
+ return EFI_SUCCESS;
+ }
+
+ status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
+ ULONG_MAX, min_kimg_align,
+ EFI_LOADER_CODE);
+
+ if (status != EFI_SUCCESS) {
+ efi_err("Failed to relocate kernel\n");
+ *reserve_size = 0;
+ return status;
+ }
+ }
+
+ memcpy((void *)*reserve_addr, (void *)*image_addr, kernel_size);
+ *image_addr = *reserve_addr;
+ efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
+ efi_remap_image(*image_addr, *reserve_size, kernel_codesize);
+
+ return status;
+}
--
2.39.2
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v5 4/5] libstub: Fix compilation warning for rv32
2023-07-21 7:48 [PATCH v5 0/5] riscv: Introduce KASLR Alexandre Ghiti
` (2 preceding siblings ...)
2023-07-21 7:48 ` [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c Alexandre Ghiti
@ 2023-07-21 7:48 ` Alexandre Ghiti
2023-07-21 14:42 ` Ard Biesheuvel
2023-07-21 7:48 ` [PATCH v5 5/5] riscv: libstub: Implement KASLR by using generic functions Alexandre Ghiti
4 siblings, 1 reply; 12+ messages in thread
From: Alexandre Ghiti @ 2023-07-21 7:48 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Ard Biesheuvel,
Kees Cook, linux-riscv, linux-kernel, linux-efi, linux-arm-kernel
Cc: Alexandre Ghiti
Fix the following warning which appears when compiled for rv32 by using
unsigned long type instead of u64.
../drivers/firmware/efi/libstub/efi-stub-helper.c: In function 'efi_kaslr_relocate_kernel':
../drivers/firmware/efi/libstub/efi-stub-helper.c:846:28: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
846 | (u64)_end < EFI_ALLOC_LIMIT) {
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
drivers/firmware/efi/libstub/kaslr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/libstub/kaslr.c b/drivers/firmware/efi/libstub/kaslr.c
index be0c8ab0982a..afb857329799 100644
--- a/drivers/firmware/efi/libstub/kaslr.c
+++ b/drivers/firmware/efi/libstub/kaslr.c
@@ -130,7 +130,7 @@ efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
if (!check_image_region(*image_addr, kernel_memsize)) {
efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
} else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
- (u64)_end < EFI_ALLOC_LIMIT) {
+ (unsigned long)_end < EFI_ALLOC_LIMIT) {
/*
* Just execute from wherever we were loaded by the
* UEFI PE/COFF loader if the placement is suitable.
--
2.39.2
_______________________________________________
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v5 5/5] riscv: libstub: Implement KASLR by using generic functions
2023-07-21 7:48 [PATCH v5 0/5] riscv: Introduce KASLR Alexandre Ghiti
` (3 preceding siblings ...)
2023-07-21 7:48 ` [PATCH v5 4/5] libstub: Fix compilation warning for rv32 Alexandre Ghiti
@ 2023-07-21 7:48 ` Alexandre Ghiti
4 siblings, 0 replies; 12+ messages in thread
From: Alexandre Ghiti @ 2023-07-21 7:48 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Ard Biesheuvel,
Kees Cook, linux-riscv, linux-kernel, linux-efi, linux-arm-kernel
Cc: Alexandre Ghiti
We can now use arm64 functions to handle the move of the kernel physical
mapping: if KASLR is enabled, we will try to get a random seed from the
firmware, if not possible, the kernel will be moved to a location that
suits its alignment constraints.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
arch/riscv/include/asm/efi.h | 2 ++
arch/riscv/kernel/image-vars.h | 1 +
drivers/firmware/efi/libstub/riscv-stub.c | 33 +++++++++++------------
3 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/arch/riscv/include/asm/efi.h b/arch/riscv/include/asm/efi.h
index 29e9a0d84b16..00b24ba55035 100644
--- a/arch/riscv/include/asm/efi.h
+++ b/arch/riscv/include/asm/efi.h
@@ -51,4 +51,6 @@ void efi_virtmap_unload(void);
unsigned long stext_offset(void);
+void efi_icache_sync(unsigned long start, unsigned long end);
+
#endif /* _ASM_EFI_H */
diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h
index 15616155008c..ea1a10355ce9 100644
--- a/arch/riscv/kernel/image-vars.h
+++ b/arch/riscv/kernel/image-vars.h
@@ -27,6 +27,7 @@ __efistub__start = _start;
__efistub__start_kernel = _start_kernel;
__efistub__end = _end;
__efistub__edata = _edata;
+__efistub___init_text_end = __init_text_end;
__efistub_screen_info = screen_info;
#endif
diff --git a/drivers/firmware/efi/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c
index 145c9f0ba217..c96d6dcee86c 100644
--- a/drivers/firmware/efi/libstub/riscv-stub.c
+++ b/drivers/firmware/efi/libstub/riscv-stub.c
@@ -30,32 +30,29 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
efi_loaded_image_t *image,
efi_handle_t image_handle)
{
- unsigned long kernel_size = 0;
- unsigned long preferred_addr;
+ unsigned long kernel_size, kernel_codesize, kernel_memsize;
efi_status_t status;
kernel_size = _edata - _start;
+ kernel_codesize = __init_text_end - _start;
+ kernel_memsize = kernel_size + (_end - _edata);
*image_addr = (unsigned long)_start;
- *image_size = kernel_size + (_end - _edata);
-
- /*
- * RISC-V kernel maps PAGE_OFFSET virtual address to the same physical
- * address where kernel is booted. That's why kernel should boot from
- * as low as possible to avoid wastage of memory. Currently, dram_base
- * is occupied by the firmware. So the preferred address for kernel to
- * boot is next aligned address. If preferred address is not available,
- * relocate_kernel will fall back to efi_low_alloc_above to allocate
- * lowest possible memory region as long as the address and size meets
- * the alignment constraints.
- */
- preferred_addr = EFI_KIMG_PREFERRED_ADDRESS;
- status = efi_relocate_kernel(image_addr, kernel_size, *image_size,
- preferred_addr, efi_get_kimg_min_align(),
- 0x0);
+ *image_size = kernel_memsize;
+ *reserve_size = *image_size;
+ status = efi_kaslr_relocate_kernel(image_addr,
+ reserve_addr, reserve_size,
+ kernel_size, kernel_codesize, kernel_memsize,
+ efi_kaslr_get_phys_seed(image_handle));
if (status != EFI_SUCCESS) {
efi_err("Failed to relocate kernel\n");
*image_size = 0;
}
+
return status;
}
+
+void efi_icache_sync(unsigned long start, unsigned long end)
+{
+ asm volatile ("fence.i" ::: "memory");
+}
--
2.39.2
_______________________________________________
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^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
2023-07-21 7:48 ` [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c Alexandre Ghiti
@ 2023-07-21 14:41 ` Ard Biesheuvel
2023-07-22 9:13 ` Alexandre Ghiti
2023-07-21 19:59 ` kernel test robot
` (2 subsequent siblings)
3 siblings, 1 reply; 12+ messages in thread
From: Ard Biesheuvel @ 2023-07-21 14:41 UTC (permalink / raw)
To: Alexandre Ghiti
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Kees Cook, linux-riscv,
linux-kernel, linux-efi, linux-arm-kernel
On Fri, 21 Jul 2023 at 09:51, Alexandre Ghiti <alexghiti@rivosinc.com> wrote:
>
> This prepares for riscv to use the same functions to handle the pĥysical
> kernel move when KASLR is enabled.
>
> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
> ---
> arch/arm64/include/asm/efi.h | 2 +
> drivers/firmware/efi/libstub/Makefile | 3 +-
> drivers/firmware/efi/libstub/arm64-stub.c | 117 ++--------------
> drivers/firmware/efi/libstub/efistub.h | 8 ++
> drivers/firmware/efi/libstub/kaslr.c | 159 ++++++++++++++++++++++
> 5 files changed, 184 insertions(+), 105 deletions(-)
> create mode 100644 drivers/firmware/efi/libstub/kaslr.c
>
> diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
> index 4cf2cb053bc8..46273ee89445 100644
> --- a/arch/arm64/include/asm/efi.h
> +++ b/arch/arm64/include/asm/efi.h
> @@ -168,4 +168,6 @@ static inline void efi_capsule_flush_cache_range(void *addr, int size)
>
> efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f);
>
> +void efi_icache_sync(unsigned long start, unsigned long end);
> +
This needs to be in efistub.h or you are breaking the build on other
architectures (including RISC-V until the final patch of the series is
applied)
x86 also chokes on the missing efi_get_kimg_min_align() so something
should be done for that as well in this patch.
Alternatively, you could add kaslr.o to lib-$(CONFIG_ARM64) only, and
add it to lib-$(CONFIG_RISCV) too in the final patch.
> #endif /* _ASM_EFI_H */
> diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> index 16d64a34d1e1..d363c806e87d 100644
> --- a/drivers/firmware/efi/libstub/Makefile
> +++ b/drivers/firmware/efi/libstub/Makefile
> @@ -67,7 +67,8 @@ OBJECT_FILES_NON_STANDARD := y
> # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
> KCOV_INSTRUMENT := n
>
> -lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \
> +lib-y := efi-stub-helper.o kaslr.o \
> + gop.o secureboot.o tpm.o \
> file.o mem.o random.o randomalloc.o pci.o \
> skip_spaces.o lib-cmdline.o lib-ctype.o \
> alignedmem.o relocate.o printk.o vsprintf.o
> diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
> index 770b8ecb7398..452b7ccd330e 100644
> --- a/drivers/firmware/efi/libstub/arm64-stub.c
> +++ b/drivers/firmware/efi/libstub/arm64-stub.c
> @@ -14,42 +14,6 @@
>
> #include "efistub.h"
>
> -/*
> - * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
> - * to provide space, and fail to zero it). Check for this condition by double
> - * checking that the first and the last byte of the image are covered by the
> - * same EFI memory map entry.
> - */
> -static bool check_image_region(u64 base, u64 size)
> -{
> - struct efi_boot_memmap *map;
> - efi_status_t status;
> - bool ret = false;
> - int map_offset;
> -
> - status = efi_get_memory_map(&map, false);
> - if (status != EFI_SUCCESS)
> - return false;
> -
> - for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) {
> - efi_memory_desc_t *md = (void *)map->map + map_offset;
> - u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
> -
> - /*
> - * Find the region that covers base, and return whether
> - * it covers base+size bytes.
> - */
> - if (base >= md->phys_addr && base < end) {
> - ret = (base + size) <= end;
> - break;
> - }
> - }
> -
> - efi_bs_call(free_pool, map);
> -
> - return ret;
> -}
> -
> efi_status_t handle_kernel_image(unsigned long *image_addr,
> unsigned long *image_size,
> unsigned long *reserve_addr,
> @@ -59,31 +23,6 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> {
> efi_status_t status;
> unsigned long kernel_size, kernel_codesize, kernel_memsize;
> - u32 phys_seed = 0;
> - u64 min_kimg_align = efi_get_kimg_min_align();
> -
> - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
> - efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
> - void *p;
> -
> - if (efi_nokaslr) {
> - efi_info("KASLR disabled on kernel command line\n");
> - } else if (efi_bs_call(handle_protocol, image_handle,
> - &li_fixed_proto, &p) == EFI_SUCCESS) {
> - efi_info("Image placement fixed by loader\n");
> - } else {
> - status = efi_get_random_bytes(sizeof(phys_seed),
> - (u8 *)&phys_seed);
> - if (status == EFI_NOT_FOUND) {
> - efi_info("EFI_RNG_PROTOCOL unavailable\n");
> - efi_nokaslr = true;
> - } else if (status != EFI_SUCCESS) {
> - efi_err("efi_get_random_bytes() failed (0x%lx)\n",
> - status);
> - efi_nokaslr = true;
> - }
> - }
> - }
>
> if (image->image_base != _text) {
> efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
> @@ -98,50 +37,15 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> kernel_codesize = __inittext_end - _text;
> kernel_memsize = kernel_size + (_end - _edata);
> *reserve_size = kernel_memsize;
> + *image_addr = (unsigned long)_text;
>
> - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
> - /*
> - * If KASLR is enabled, and we have some randomness available,
> - * locate the kernel at a randomized offset in physical memory.
> - */
> - status = efi_random_alloc(*reserve_size, min_kimg_align,
> - reserve_addr, phys_seed,
> - EFI_LOADER_CODE);
> - if (status != EFI_SUCCESS)
> - efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
> - } else {
> - status = EFI_OUT_OF_RESOURCES;
> - }
> -
> - if (status != EFI_SUCCESS) {
> - if (!check_image_region((u64)_text, kernel_memsize)) {
> - efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
> - } else if (IS_ALIGNED((u64)_text, min_kimg_align) &&
> - (u64)_end < EFI_ALLOC_LIMIT) {
> - /*
> - * Just execute from wherever we were loaded by the
> - * UEFI PE/COFF loader if the placement is suitable.
> - */
> - *image_addr = (u64)_text;
> - *reserve_size = 0;
> - return EFI_SUCCESS;
> - }
> -
> - status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
> - ULONG_MAX, min_kimg_align,
> - EFI_LOADER_CODE);
> -
> - if (status != EFI_SUCCESS) {
> - efi_err("Failed to relocate kernel\n");
> - *reserve_size = 0;
> - return status;
> - }
> - }
> -
> - *image_addr = *reserve_addr;
> - memcpy((void *)*image_addr, _text, kernel_size);
> - caches_clean_inval_pou(*image_addr, *image_addr + kernel_codesize);
> - efi_remap_image(*image_addr, *reserve_size, kernel_codesize);
> + status = efi_kaslr_relocate_kernel(image_addr,
> + reserve_addr, reserve_size,
> + kernel_size, kernel_codesize,
> + kernel_memsize,
> + efi_kaslr_get_phys_seed(image_handle));
> + if (status != EFI_SUCCESS)
> + return status;
>
> return EFI_SUCCESS;
> }
> @@ -159,3 +63,8 @@ unsigned long primary_entry_offset(void)
> */
> return (char *)primary_entry - _text;
> }
> +
> +void efi_icache_sync(unsigned long start, unsigned long end)
> +{
> + caches_clean_inval_pou(start, end);
> +}
> diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
> index 6aa38a1bf126..b1a1037567ba 100644
> --- a/drivers/firmware/efi/libstub/efistub.h
> +++ b/drivers/firmware/efi/libstub/efistub.h
> @@ -1132,6 +1132,14 @@ const u8 *__efi_get_smbios_string(const struct efi_smbios_record *record,
>
> void efi_remap_image(unsigned long image_base, unsigned alloc_size,
> unsigned long code_size);
> +efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
> + unsigned long *reserve_addr,
> + unsigned long *reserve_size,
> + unsigned long kernel_size,
> + unsigned long kernel_codesize,
> + unsigned long kernel_memsize,
> + u32 phys_seed);
> +u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle);
>
> asmlinkage efi_status_t __efiapi
> efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab);
> diff --git a/drivers/firmware/efi/libstub/kaslr.c b/drivers/firmware/efi/libstub/kaslr.c
> new file mode 100644
> index 000000000000..be0c8ab0982a
> --- /dev/null
> +++ b/drivers/firmware/efi/libstub/kaslr.c
> @@ -0,0 +1,159 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Helper functions used by the EFI stub on multiple
> + * architectures to deal with physical address space randomization.
> + */
> +#include <linux/efi.h>
> +
> +#include "efistub.h"
> +
> +/**
> + * efi_kaslr_get_phys_seed() - Get random seed for physical kernel KASLR
> + * @image_handle: Handle to the image
> + *
> + * If KASLR is not disabled, obtain a random seed using EFI_RNG_PROTOCOL
> + * that will be used to move the kernel physical mapping.
> + *
> + * Return: the random seed
> + */
> +u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle)
> +{
> + efi_status_t status;
> + u32 phys_seed;
> + efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
> + void *p;
> +
> + if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
> + return 0;
> +
> + if (efi_nokaslr) {
> + efi_info("KASLR disabled on kernel command line\n");
> + } else if (efi_bs_call(handle_protocol, image_handle,
> + &li_fixed_proto, &p) == EFI_SUCCESS) {
> + efi_info("Image placement fixed by loader\n");
> + } else {
> + status = efi_get_random_bytes(sizeof(phys_seed),
> + (u8 *)&phys_seed);
> + if (status == EFI_SUCCESS) {
> + return phys_seed;
> + } else if (status == EFI_NOT_FOUND) {
> + efi_info("EFI_RNG_PROTOCOL unavailable\n");
> + efi_nokaslr = true;
> + } else if (status != EFI_SUCCESS) {
> + efi_err("efi_get_random_bytes() failed (0x%lx)\n",
> + status);
> + efi_nokaslr = true;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
> + * to provide space, and fail to zero it). Check for this condition by double
> + * checking that the first and the last byte of the image are covered by the
> + * same EFI memory map entry.
> + */
> +static bool check_image_region(u64 base, u64 size)
> +{
> + struct efi_boot_memmap *map;
> + efi_status_t status;
> + bool ret = false;
> + int map_offset;
> +
> + status = efi_get_memory_map(&map, false);
> + if (status != EFI_SUCCESS)
> + return false;
> +
> + for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) {
> + efi_memory_desc_t *md = (void *)map->map + map_offset;
> + u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
> +
> + /*
> + * Find the region that covers base, and return whether
> + * it covers base+size bytes.
> + */
> + if (base >= md->phys_addr && base < end) {
> + ret = (base + size) <= end;
> + break;
> + }
> + }
> +
> + efi_bs_call(free_pool, map);
> +
> + return ret;
> +}
> +
> +/**
> + * efi_kaslr_relocate_kernel() - Relocate the kernel (random if KASLR enabled)
> + * @image_addr: Pointer to the current kernel location
> + * @reserve_addr: Pointer to the relocated kernel location
> + * @reserve_size: Size of the relocated kernel
> + * @kernel_size: Size of the text + data
> + * @kernel_codesize: Size of the text
> + * @kernel_memsize: Size of the text + data + bss
> + * @phys_seed: Random seed used for the relocation
> + *
> + * If KASLR is not enabled, this function relocates the kernel to a fixed
> + * address (or leave it as its current location). If KASLR is enabled, the
> + * kernel physical location is randomized using the seed in parameter.
> + *
> + * Return: status code, EFI_SUCCESS if relocation is successful
> + */
> +efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
> + unsigned long *reserve_addr,
> + unsigned long *reserve_size,
> + unsigned long kernel_size,
> + unsigned long kernel_codesize,
> + unsigned long kernel_memsize,
> + u32 phys_seed)
> +{
> + efi_status_t status;
> + u64 min_kimg_align = efi_get_kimg_min_align();
> +
> + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
> + /*
> + * If KASLR is enabled, and we have some randomness available,
> + * locate the kernel at a randomized offset in physical memory.
> + */
> + status = efi_random_alloc(*reserve_size, min_kimg_align,
> + reserve_addr, phys_seed,
> + EFI_LOADER_CODE);
> + if (status != EFI_SUCCESS)
> + efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
> + } else {
> + status = EFI_OUT_OF_RESOURCES;
> + }
> +
> + if (status != EFI_SUCCESS) {
> + if (!check_image_region(*image_addr, kernel_memsize)) {
> + efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
> + } else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
> + (u64)_end < EFI_ALLOC_LIMIT) {
> + /*
> + * Just execute from wherever we were loaded by the
> + * UEFI PE/COFF loader if the placement is suitable.
> + */
> + *reserve_size = 0;
> + return EFI_SUCCESS;
> + }
> +
> + status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
> + ULONG_MAX, min_kimg_align,
> + EFI_LOADER_CODE);
> +
> + if (status != EFI_SUCCESS) {
> + efi_err("Failed to relocate kernel\n");
> + *reserve_size = 0;
> + return status;
> + }
> + }
> +
> + memcpy((void *)*reserve_addr, (void *)*image_addr, kernel_size);
> + *image_addr = *reserve_addr;
> + efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
> + efi_remap_image(*image_addr, *reserve_size, kernel_codesize);
> +
> + return status;
> +}
> --
> 2.39.2
>
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v5 4/5] libstub: Fix compilation warning for rv32
2023-07-21 7:48 ` [PATCH v5 4/5] libstub: Fix compilation warning for rv32 Alexandre Ghiti
@ 2023-07-21 14:42 ` Ard Biesheuvel
0 siblings, 0 replies; 12+ messages in thread
From: Ard Biesheuvel @ 2023-07-21 14:42 UTC (permalink / raw)
To: Alexandre Ghiti
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Kees Cook, linux-riscv,
linux-kernel, linux-efi, linux-arm-kernel
On Fri, 21 Jul 2023 at 09:52, Alexandre Ghiti <alexghiti@rivosinc.com> wrote:
>
> Fix the following warning which appears when compiled for rv32 by using
> unsigned long type instead of u64.
>
> ../drivers/firmware/efi/libstub/efi-stub-helper.c: In function 'efi_kaslr_relocate_kernel':
> ../drivers/firmware/efi/libstub/efi-stub-helper.c:846:28: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
> 846 | (u64)_end < EFI_ALLOC_LIMIT) {
>
> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
For all I care, you can just squash this into the previous patch as well.
> ---
> drivers/firmware/efi/libstub/kaslr.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/efi/libstub/kaslr.c b/drivers/firmware/efi/libstub/kaslr.c
> index be0c8ab0982a..afb857329799 100644
> --- a/drivers/firmware/efi/libstub/kaslr.c
> +++ b/drivers/firmware/efi/libstub/kaslr.c
> @@ -130,7 +130,7 @@ efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
> if (!check_image_region(*image_addr, kernel_memsize)) {
> efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
> } else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
> - (u64)_end < EFI_ALLOC_LIMIT) {
> + (unsigned long)_end < EFI_ALLOC_LIMIT) {
> /*
> * Just execute from wherever we were loaded by the
> * UEFI PE/COFF loader if the placement is suitable.
> --
> 2.39.2
>
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
2023-07-21 7:48 ` [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c Alexandre Ghiti
2023-07-21 14:41 ` Ard Biesheuvel
@ 2023-07-21 19:59 ` kernel test robot
2023-07-21 20:31 ` kernel test robot
2023-07-21 21:32 ` kernel test robot
3 siblings, 0 replies; 12+ messages in thread
From: kernel test robot @ 2023-07-21 19:59 UTC (permalink / raw)
To: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Ard Biesheuvel, Kees Cook, linux-riscv, linux-kernel, linux-efi,
linux-arm-kernel
Cc: oe-kbuild-all, Alexandre Ghiti
Hi Alexandre,
kernel test robot noticed the following build errors:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.5-rc2 next-20230721]
[cannot apply to efi/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Alexandre-Ghiti/riscv-Introduce-virtual-kernel-mapping-KASLR/20230721-155554
base: linus/master
patch link: https://lore.kernel.org/r/20230721074850.310644-4-alexghiti%40rivosinc.com
patch subject: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
config: loongarch-defconfig (https://download.01.org/0day-ci/archive/20230722/202307220314.ZZIxEjW2-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230722/202307220314.ZZIxEjW2-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307220314.ZZIxEjW2-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/firmware/efi/libstub/kaslr.c: In function 'efi_kaslr_relocate_kernel':
>> drivers/firmware/efi/libstub/kaslr.c:155:9: error: implicit declaration of function 'efi_icache_sync'; did you mean 'efi_cache_sync_image'? [-Werror=implicit-function-declaration]
155 | efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
| ^~~~~~~~~~~~~~~
| efi_cache_sync_image
cc1: some warnings being treated as errors
vim +155 drivers/firmware/efi/libstub/kaslr.c
87
88 /**
89 * efi_kaslr_relocate_kernel() - Relocate the kernel (random if KASLR enabled)
90 * @image_addr: Pointer to the current kernel location
91 * @reserve_addr: Pointer to the relocated kernel location
92 * @reserve_size: Size of the relocated kernel
93 * @kernel_size: Size of the text + data
94 * @kernel_codesize: Size of the text
95 * @kernel_memsize: Size of the text + data + bss
96 * @phys_seed: Random seed used for the relocation
97 *
98 * If KASLR is not enabled, this function relocates the kernel to a fixed
99 * address (or leave it as its current location). If KASLR is enabled, the
100 * kernel physical location is randomized using the seed in parameter.
101 *
102 * Return: status code, EFI_SUCCESS if relocation is successful
103 */
104 efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
105 unsigned long *reserve_addr,
106 unsigned long *reserve_size,
107 unsigned long kernel_size,
108 unsigned long kernel_codesize,
109 unsigned long kernel_memsize,
110 u32 phys_seed)
111 {
112 efi_status_t status;
113 u64 min_kimg_align = efi_get_kimg_min_align();
114
115 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
116 /*
117 * If KASLR is enabled, and we have some randomness available,
118 * locate the kernel at a randomized offset in physical memory.
119 */
120 status = efi_random_alloc(*reserve_size, min_kimg_align,
121 reserve_addr, phys_seed,
122 EFI_LOADER_CODE);
123 if (status != EFI_SUCCESS)
124 efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
125 } else {
126 status = EFI_OUT_OF_RESOURCES;
127 }
128
129 if (status != EFI_SUCCESS) {
130 if (!check_image_region(*image_addr, kernel_memsize)) {
131 efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
132 } else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
133 (u64)_end < EFI_ALLOC_LIMIT) {
134 /*
135 * Just execute from wherever we were loaded by the
136 * UEFI PE/COFF loader if the placement is suitable.
137 */
138 *reserve_size = 0;
139 return EFI_SUCCESS;
140 }
141
142 status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
143 ULONG_MAX, min_kimg_align,
144 EFI_LOADER_CODE);
145
146 if (status != EFI_SUCCESS) {
147 efi_err("Failed to relocate kernel\n");
148 *reserve_size = 0;
149 return status;
150 }
151 }
152
153 memcpy((void *)*reserve_addr, (void *)*image_addr, kernel_size);
154 *image_addr = *reserve_addr;
> 155 efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
_______________________________________________
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linux-riscv@lists.infradead.org
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
2023-07-21 7:48 ` [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c Alexandre Ghiti
2023-07-21 14:41 ` Ard Biesheuvel
2023-07-21 19:59 ` kernel test robot
@ 2023-07-21 20:31 ` kernel test robot
2023-07-21 21:32 ` kernel test robot
3 siblings, 0 replies; 12+ messages in thread
From: kernel test robot @ 2023-07-21 20:31 UTC (permalink / raw)
To: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Ard Biesheuvel, Kees Cook, linux-riscv, linux-kernel, linux-efi,
linux-arm-kernel
Cc: oe-kbuild-all, Alexandre Ghiti
Hi Alexandre,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.5-rc2 next-20230721]
[cannot apply to efi/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Alexandre-Ghiti/riscv-Introduce-virtual-kernel-mapping-KASLR/20230721-155554
base: linus/master
patch link: https://lore.kernel.org/r/20230721074850.310644-4-alexghiti%40rivosinc.com
patch subject: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20230722/202307220429.jaPTVAph-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230722/202307220429.jaPTVAph-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307220429.jaPTVAph-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/firmware/efi/libstub/kaslr.c: In function 'efi_kaslr_relocate_kernel':
>> drivers/firmware/efi/libstub/kaslr.c:113:30: warning: implicit declaration of function 'efi_get_kimg_min_align' [-Wimplicit-function-declaration]
113 | u64 min_kimg_align = efi_get_kimg_min_align();
| ^~~~~~~~~~~~~~~~~~~~~~
>> drivers/firmware/efi/libstub/kaslr.c:155:9: warning: implicit declaration of function 'efi_icache_sync'; did you mean 'efi_cache_sync_image'? [-Wimplicit-function-declaration]
155 | efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
| ^~~~~~~~~~~~~~~
| efi_cache_sync_image
vim +/efi_get_kimg_min_align +113 drivers/firmware/efi/libstub/kaslr.c
87
88 /**
89 * efi_kaslr_relocate_kernel() - Relocate the kernel (random if KASLR enabled)
90 * @image_addr: Pointer to the current kernel location
91 * @reserve_addr: Pointer to the relocated kernel location
92 * @reserve_size: Size of the relocated kernel
93 * @kernel_size: Size of the text + data
94 * @kernel_codesize: Size of the text
95 * @kernel_memsize: Size of the text + data + bss
96 * @phys_seed: Random seed used for the relocation
97 *
98 * If KASLR is not enabled, this function relocates the kernel to a fixed
99 * address (or leave it as its current location). If KASLR is enabled, the
100 * kernel physical location is randomized using the seed in parameter.
101 *
102 * Return: status code, EFI_SUCCESS if relocation is successful
103 */
104 efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
105 unsigned long *reserve_addr,
106 unsigned long *reserve_size,
107 unsigned long kernel_size,
108 unsigned long kernel_codesize,
109 unsigned long kernel_memsize,
110 u32 phys_seed)
111 {
112 efi_status_t status;
> 113 u64 min_kimg_align = efi_get_kimg_min_align();
114
115 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
116 /*
117 * If KASLR is enabled, and we have some randomness available,
118 * locate the kernel at a randomized offset in physical memory.
119 */
120 status = efi_random_alloc(*reserve_size, min_kimg_align,
121 reserve_addr, phys_seed,
122 EFI_LOADER_CODE);
123 if (status != EFI_SUCCESS)
124 efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
125 } else {
126 status = EFI_OUT_OF_RESOURCES;
127 }
128
129 if (status != EFI_SUCCESS) {
130 if (!check_image_region(*image_addr, kernel_memsize)) {
131 efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
132 } else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
133 (u64)_end < EFI_ALLOC_LIMIT) {
134 /*
135 * Just execute from wherever we were loaded by the
136 * UEFI PE/COFF loader if the placement is suitable.
137 */
138 *reserve_size = 0;
139 return EFI_SUCCESS;
140 }
141
142 status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
143 ULONG_MAX, min_kimg_align,
144 EFI_LOADER_CODE);
145
146 if (status != EFI_SUCCESS) {
147 efi_err("Failed to relocate kernel\n");
148 *reserve_size = 0;
149 return status;
150 }
151 }
152
153 memcpy((void *)*reserve_addr, (void *)*image_addr, kernel_size);
154 *image_addr = *reserve_addr;
> 155 efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
2023-07-21 7:48 ` [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c Alexandre Ghiti
` (2 preceding siblings ...)
2023-07-21 20:31 ` kernel test robot
@ 2023-07-21 21:32 ` kernel test robot
3 siblings, 0 replies; 12+ messages in thread
From: kernel test robot @ 2023-07-21 21:32 UTC (permalink / raw)
To: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Ard Biesheuvel, Kees Cook, linux-riscv, linux-kernel, linux-efi,
linux-arm-kernel
Cc: llvm, oe-kbuild-all, Alexandre Ghiti
Hi Alexandre,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.5-rc2 next-20230721]
[cannot apply to efi/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Alexandre-Ghiti/riscv-Introduce-virtual-kernel-mapping-KASLR/20230721-155554
base: linus/master
patch link: https://lore.kernel.org/r/20230721074850.310644-4-alexghiti%40rivosinc.com
patch subject: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
config: i386-randconfig-i002-20230721 (https://download.01.org/0day-ci/archive/20230722/202307220545.aNYBwGqt-lkp@intel.com/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce: (https://download.01.org/0day-ci/archive/20230722/202307220545.aNYBwGqt-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307220545.aNYBwGqt-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/firmware/efi/libstub/kaslr.c:113:23: warning: call to undeclared function 'efi_get_kimg_min_align'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
u64 min_kimg_align = efi_get_kimg_min_align();
^
>> drivers/firmware/efi/libstub/kaslr.c:155:2: warning: call to undeclared function 'efi_icache_sync'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
^
2 warnings generated.
vim +/efi_get_kimg_min_align +113 drivers/firmware/efi/libstub/kaslr.c
87
88 /**
89 * efi_kaslr_relocate_kernel() - Relocate the kernel (random if KASLR enabled)
90 * @image_addr: Pointer to the current kernel location
91 * @reserve_addr: Pointer to the relocated kernel location
92 * @reserve_size: Size of the relocated kernel
93 * @kernel_size: Size of the text + data
94 * @kernel_codesize: Size of the text
95 * @kernel_memsize: Size of the text + data + bss
96 * @phys_seed: Random seed used for the relocation
97 *
98 * If KASLR is not enabled, this function relocates the kernel to a fixed
99 * address (or leave it as its current location). If KASLR is enabled, the
100 * kernel physical location is randomized using the seed in parameter.
101 *
102 * Return: status code, EFI_SUCCESS if relocation is successful
103 */
104 efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
105 unsigned long *reserve_addr,
106 unsigned long *reserve_size,
107 unsigned long kernel_size,
108 unsigned long kernel_codesize,
109 unsigned long kernel_memsize,
110 u32 phys_seed)
111 {
112 efi_status_t status;
> 113 u64 min_kimg_align = efi_get_kimg_min_align();
114
115 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
116 /*
117 * If KASLR is enabled, and we have some randomness available,
118 * locate the kernel at a randomized offset in physical memory.
119 */
120 status = efi_random_alloc(*reserve_size, min_kimg_align,
121 reserve_addr, phys_seed,
122 EFI_LOADER_CODE);
123 if (status != EFI_SUCCESS)
124 efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
125 } else {
126 status = EFI_OUT_OF_RESOURCES;
127 }
128
129 if (status != EFI_SUCCESS) {
130 if (!check_image_region(*image_addr, kernel_memsize)) {
131 efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
132 } else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
133 (u64)_end < EFI_ALLOC_LIMIT) {
134 /*
135 * Just execute from wherever we were loaded by the
136 * UEFI PE/COFF loader if the placement is suitable.
137 */
138 *reserve_size = 0;
139 return EFI_SUCCESS;
140 }
141
142 status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
143 ULONG_MAX, min_kimg_align,
144 EFI_LOADER_CODE);
145
146 if (status != EFI_SUCCESS) {
147 efi_err("Failed to relocate kernel\n");
148 *reserve_size = 0;
149 return status;
150 }
151 }
152
153 memcpy((void *)*reserve_addr, (void *)*image_addr, kernel_size);
154 *image_addr = *reserve_addr;
> 155 efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c
2023-07-21 14:41 ` Ard Biesheuvel
@ 2023-07-22 9:13 ` Alexandre Ghiti
0 siblings, 0 replies; 12+ messages in thread
From: Alexandre Ghiti @ 2023-07-22 9:13 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Kees Cook, linux-riscv,
linux-kernel, linux-efi, linux-arm-kernel
Hi Ard,
On Fri, Jul 21, 2023 at 4:41 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Fri, 21 Jul 2023 at 09:51, Alexandre Ghiti <alexghiti@rivosinc.com> wrote:
> >
> > This prepares for riscv to use the same functions to handle the pĥysical
> > kernel move when KASLR is enabled.
> >
> > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
> > ---
> > arch/arm64/include/asm/efi.h | 2 +
> > drivers/firmware/efi/libstub/Makefile | 3 +-
> > drivers/firmware/efi/libstub/arm64-stub.c | 117 ++--------------
> > drivers/firmware/efi/libstub/efistub.h | 8 ++
> > drivers/firmware/efi/libstub/kaslr.c | 159 ++++++++++++++++++++++
> > 5 files changed, 184 insertions(+), 105 deletions(-)
> > create mode 100644 drivers/firmware/efi/libstub/kaslr.c
> >
> > diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
> > index 4cf2cb053bc8..46273ee89445 100644
> > --- a/arch/arm64/include/asm/efi.h
> > +++ b/arch/arm64/include/asm/efi.h
> > @@ -168,4 +168,6 @@ static inline void efi_capsule_flush_cache_range(void *addr, int size)
> >
> > efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f);
> >
> > +void efi_icache_sync(unsigned long start, unsigned long end);
> > +
>
> This needs to be in efistub.h or you are breaking the build on other
> architectures (including RISC-V until the final patch of the series is
> applied)
>
> x86 also chokes on the missing efi_get_kimg_min_align() so something
> should be done for that as well in this patch.
>
> Alternatively, you could add kaslr.o to lib-$(CONFIG_ARM64) only, and
> add it to lib-$(CONFIG_RISCV) too in the final patch.
>
Sorry about that, I was so focused on the linking errors that I did
not see those warnings...I'll go with the solution you propose rather
than introducing stubs like v3 did.
Sorry again and thanks,
Alex
>
> > #endif /* _ASM_EFI_H */
> > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> > index 16d64a34d1e1..d363c806e87d 100644
> > --- a/drivers/firmware/efi/libstub/Makefile
> > +++ b/drivers/firmware/efi/libstub/Makefile
> > @@ -67,7 +67,8 @@ OBJECT_FILES_NON_STANDARD := y
> > # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
> > KCOV_INSTRUMENT := n
> >
> > -lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \
> > +lib-y := efi-stub-helper.o kaslr.o \
> > + gop.o secureboot.o tpm.o \
> > file.o mem.o random.o randomalloc.o pci.o \
> > skip_spaces.o lib-cmdline.o lib-ctype.o \
> > alignedmem.o relocate.o printk.o vsprintf.o
> > diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
> > index 770b8ecb7398..452b7ccd330e 100644
> > --- a/drivers/firmware/efi/libstub/arm64-stub.c
> > +++ b/drivers/firmware/efi/libstub/arm64-stub.c
> > @@ -14,42 +14,6 @@
> >
> > #include "efistub.h"
> >
> > -/*
> > - * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
> > - * to provide space, and fail to zero it). Check for this condition by double
> > - * checking that the first and the last byte of the image are covered by the
> > - * same EFI memory map entry.
> > - */
> > -static bool check_image_region(u64 base, u64 size)
> > -{
> > - struct efi_boot_memmap *map;
> > - efi_status_t status;
> > - bool ret = false;
> > - int map_offset;
> > -
> > - status = efi_get_memory_map(&map, false);
> > - if (status != EFI_SUCCESS)
> > - return false;
> > -
> > - for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) {
> > - efi_memory_desc_t *md = (void *)map->map + map_offset;
> > - u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
> > -
> > - /*
> > - * Find the region that covers base, and return whether
> > - * it covers base+size bytes.
> > - */
> > - if (base >= md->phys_addr && base < end) {
> > - ret = (base + size) <= end;
> > - break;
> > - }
> > - }
> > -
> > - efi_bs_call(free_pool, map);
> > -
> > - return ret;
> > -}
> > -
> > efi_status_t handle_kernel_image(unsigned long *image_addr,
> > unsigned long *image_size,
> > unsigned long *reserve_addr,
> > @@ -59,31 +23,6 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> > {
> > efi_status_t status;
> > unsigned long kernel_size, kernel_codesize, kernel_memsize;
> > - u32 phys_seed = 0;
> > - u64 min_kimg_align = efi_get_kimg_min_align();
> > -
> > - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
> > - efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
> > - void *p;
> > -
> > - if (efi_nokaslr) {
> > - efi_info("KASLR disabled on kernel command line\n");
> > - } else if (efi_bs_call(handle_protocol, image_handle,
> > - &li_fixed_proto, &p) == EFI_SUCCESS) {
> > - efi_info("Image placement fixed by loader\n");
> > - } else {
> > - status = efi_get_random_bytes(sizeof(phys_seed),
> > - (u8 *)&phys_seed);
> > - if (status == EFI_NOT_FOUND) {
> > - efi_info("EFI_RNG_PROTOCOL unavailable\n");
> > - efi_nokaslr = true;
> > - } else if (status != EFI_SUCCESS) {
> > - efi_err("efi_get_random_bytes() failed (0x%lx)\n",
> > - status);
> > - efi_nokaslr = true;
> > - }
> > - }
> > - }
> >
> > if (image->image_base != _text) {
> > efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
> > @@ -98,50 +37,15 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> > kernel_codesize = __inittext_end - _text;
> > kernel_memsize = kernel_size + (_end - _edata);
> > *reserve_size = kernel_memsize;
> > + *image_addr = (unsigned long)_text;
> >
> > - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
> > - /*
> > - * If KASLR is enabled, and we have some randomness available,
> > - * locate the kernel at a randomized offset in physical memory.
> > - */
> > - status = efi_random_alloc(*reserve_size, min_kimg_align,
> > - reserve_addr, phys_seed,
> > - EFI_LOADER_CODE);
> > - if (status != EFI_SUCCESS)
> > - efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
> > - } else {
> > - status = EFI_OUT_OF_RESOURCES;
> > - }
> > -
> > - if (status != EFI_SUCCESS) {
> > - if (!check_image_region((u64)_text, kernel_memsize)) {
> > - efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
> > - } else if (IS_ALIGNED((u64)_text, min_kimg_align) &&
> > - (u64)_end < EFI_ALLOC_LIMIT) {
> > - /*
> > - * Just execute from wherever we were loaded by the
> > - * UEFI PE/COFF loader if the placement is suitable.
> > - */
> > - *image_addr = (u64)_text;
> > - *reserve_size = 0;
> > - return EFI_SUCCESS;
> > - }
> > -
> > - status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
> > - ULONG_MAX, min_kimg_align,
> > - EFI_LOADER_CODE);
> > -
> > - if (status != EFI_SUCCESS) {
> > - efi_err("Failed to relocate kernel\n");
> > - *reserve_size = 0;
> > - return status;
> > - }
> > - }
> > -
> > - *image_addr = *reserve_addr;
> > - memcpy((void *)*image_addr, _text, kernel_size);
> > - caches_clean_inval_pou(*image_addr, *image_addr + kernel_codesize);
> > - efi_remap_image(*image_addr, *reserve_size, kernel_codesize);
> > + status = efi_kaslr_relocate_kernel(image_addr,
> > + reserve_addr, reserve_size,
> > + kernel_size, kernel_codesize,
> > + kernel_memsize,
> > + efi_kaslr_get_phys_seed(image_handle));
> > + if (status != EFI_SUCCESS)
> > + return status;
> >
> > return EFI_SUCCESS;
> > }
> > @@ -159,3 +63,8 @@ unsigned long primary_entry_offset(void)
> > */
> > return (char *)primary_entry - _text;
> > }
> > +
> > +void efi_icache_sync(unsigned long start, unsigned long end)
> > +{
> > + caches_clean_inval_pou(start, end);
> > +}
> > diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
> > index 6aa38a1bf126..b1a1037567ba 100644
> > --- a/drivers/firmware/efi/libstub/efistub.h
> > +++ b/drivers/firmware/efi/libstub/efistub.h
> > @@ -1132,6 +1132,14 @@ const u8 *__efi_get_smbios_string(const struct efi_smbios_record *record,
> >
> > void efi_remap_image(unsigned long image_base, unsigned alloc_size,
> > unsigned long code_size);
> > +efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
> > + unsigned long *reserve_addr,
> > + unsigned long *reserve_size,
> > + unsigned long kernel_size,
> > + unsigned long kernel_codesize,
> > + unsigned long kernel_memsize,
> > + u32 phys_seed);
> > +u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle);
> >
> > asmlinkage efi_status_t __efiapi
> > efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab);
> > diff --git a/drivers/firmware/efi/libstub/kaslr.c b/drivers/firmware/efi/libstub/kaslr.c
> > new file mode 100644
> > index 000000000000..be0c8ab0982a
> > --- /dev/null
> > +++ b/drivers/firmware/efi/libstub/kaslr.c
> > @@ -0,0 +1,159 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Helper functions used by the EFI stub on multiple
> > + * architectures to deal with physical address space randomization.
> > + */
> > +#include <linux/efi.h>
> > +
> > +#include "efistub.h"
> > +
> > +/**
> > + * efi_kaslr_get_phys_seed() - Get random seed for physical kernel KASLR
> > + * @image_handle: Handle to the image
> > + *
> > + * If KASLR is not disabled, obtain a random seed using EFI_RNG_PROTOCOL
> > + * that will be used to move the kernel physical mapping.
> > + *
> > + * Return: the random seed
> > + */
> > +u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle)
> > +{
> > + efi_status_t status;
> > + u32 phys_seed;
> > + efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
> > + void *p;
> > +
> > + if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
> > + return 0;
> > +
> > + if (efi_nokaslr) {
> > + efi_info("KASLR disabled on kernel command line\n");
> > + } else if (efi_bs_call(handle_protocol, image_handle,
> > + &li_fixed_proto, &p) == EFI_SUCCESS) {
> > + efi_info("Image placement fixed by loader\n");
> > + } else {
> > + status = efi_get_random_bytes(sizeof(phys_seed),
> > + (u8 *)&phys_seed);
> > + if (status == EFI_SUCCESS) {
> > + return phys_seed;
> > + } else if (status == EFI_NOT_FOUND) {
> > + efi_info("EFI_RNG_PROTOCOL unavailable\n");
> > + efi_nokaslr = true;
> > + } else if (status != EFI_SUCCESS) {
> > + efi_err("efi_get_random_bytes() failed (0x%lx)\n",
> > + status);
> > + efi_nokaslr = true;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
> > + * to provide space, and fail to zero it). Check for this condition by double
> > + * checking that the first and the last byte of the image are covered by the
> > + * same EFI memory map entry.
> > + */
> > +static bool check_image_region(u64 base, u64 size)
> > +{
> > + struct efi_boot_memmap *map;
> > + efi_status_t status;
> > + bool ret = false;
> > + int map_offset;
> > +
> > + status = efi_get_memory_map(&map, false);
> > + if (status != EFI_SUCCESS)
> > + return false;
> > +
> > + for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) {
> > + efi_memory_desc_t *md = (void *)map->map + map_offset;
> > + u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
> > +
> > + /*
> > + * Find the region that covers base, and return whether
> > + * it covers base+size bytes.
> > + */
> > + if (base >= md->phys_addr && base < end) {
> > + ret = (base + size) <= end;
> > + break;
> > + }
> > + }
> > +
> > + efi_bs_call(free_pool, map);
> > +
> > + return ret;
> > +}
> > +
> > +/**
> > + * efi_kaslr_relocate_kernel() - Relocate the kernel (random if KASLR enabled)
> > + * @image_addr: Pointer to the current kernel location
> > + * @reserve_addr: Pointer to the relocated kernel location
> > + * @reserve_size: Size of the relocated kernel
> > + * @kernel_size: Size of the text + data
> > + * @kernel_codesize: Size of the text
> > + * @kernel_memsize: Size of the text + data + bss
> > + * @phys_seed: Random seed used for the relocation
> > + *
> > + * If KASLR is not enabled, this function relocates the kernel to a fixed
> > + * address (or leave it as its current location). If KASLR is enabled, the
> > + * kernel physical location is randomized using the seed in parameter.
> > + *
> > + * Return: status code, EFI_SUCCESS if relocation is successful
> > + */
> > +efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr,
> > + unsigned long *reserve_addr,
> > + unsigned long *reserve_size,
> > + unsigned long kernel_size,
> > + unsigned long kernel_codesize,
> > + unsigned long kernel_memsize,
> > + u32 phys_seed)
> > +{
> > + efi_status_t status;
> > + u64 min_kimg_align = efi_get_kimg_min_align();
> > +
> > + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
> > + /*
> > + * If KASLR is enabled, and we have some randomness available,
> > + * locate the kernel at a randomized offset in physical memory.
> > + */
> > + status = efi_random_alloc(*reserve_size, min_kimg_align,
> > + reserve_addr, phys_seed,
> > + EFI_LOADER_CODE);
> > + if (status != EFI_SUCCESS)
> > + efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
> > + } else {
> > + status = EFI_OUT_OF_RESOURCES;
> > + }
> > +
> > + if (status != EFI_SUCCESS) {
> > + if (!check_image_region(*image_addr, kernel_memsize)) {
> > + efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
> > + } else if (IS_ALIGNED(*image_addr, min_kimg_align) &&
> > + (u64)_end < EFI_ALLOC_LIMIT) {
> > + /*
> > + * Just execute from wherever we were loaded by the
> > + * UEFI PE/COFF loader if the placement is suitable.
> > + */
> > + *reserve_size = 0;
> > + return EFI_SUCCESS;
> > + }
> > +
> > + status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
> > + ULONG_MAX, min_kimg_align,
> > + EFI_LOADER_CODE);
> > +
> > + if (status != EFI_SUCCESS) {
> > + efi_err("Failed to relocate kernel\n");
> > + *reserve_size = 0;
> > + return status;
> > + }
> > + }
> > +
> > + memcpy((void *)*reserve_addr, (void *)*image_addr, kernel_size);
> > + *image_addr = *reserve_addr;
> > + efi_icache_sync(*image_addr, *image_addr + kernel_codesize);
> > + efi_remap_image(*image_addr, *reserve_size, kernel_codesize);
> > +
> > + return status;
> > +}
> > --
> > 2.39.2
> >
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^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2023-07-22 9:13 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-07-21 7:48 [PATCH v5 0/5] riscv: Introduce KASLR Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 1/5] riscv: Introduce virtual kernel mapping KASLR Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 2/5] riscv: Dump out kernel offset information on panic Alexandre Ghiti
2023-07-21 7:48 ` [PATCH v5 3/5] arm64: libstub: Move KASLR handling functions to kaslr.c Alexandre Ghiti
2023-07-21 14:41 ` Ard Biesheuvel
2023-07-22 9:13 ` Alexandre Ghiti
2023-07-21 19:59 ` kernel test robot
2023-07-21 20:31 ` kernel test robot
2023-07-21 21:32 ` kernel test robot
2023-07-21 7:48 ` [PATCH v5 4/5] libstub: Fix compilation warning for rv32 Alexandre Ghiti
2023-07-21 14:42 ` Ard Biesheuvel
2023-07-21 7:48 ` [PATCH v5 5/5] riscv: libstub: Implement KASLR by using generic functions Alexandre Ghiti
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