* [PATCH v2 1/2] efi: Rename efi_early_memdesc_ptr() to efi_memdesc_ptr()
2024-07-11 17:11 [PATCH v2 0/2] efi: Replace efi_memory_attributes_table_t 0-sized array with flexible array Kees Cook
@ 2024-07-11 17:11 ` Kees Cook
2024-07-11 17:11 ` [PATCH v2 2/2] efi: Replace efi_memory_attributes_table_t 0-sized array with flexible array Kees Cook
2024-07-12 8:08 ` [PATCH v2 0/2] " Ard Biesheuvel
2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2024-07-11 17:11 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Kees Cook, Kirill A. Shutemov, Borislav Petkov (AMD),
Baskov Evgeniy, linux-efi, Ingo Molnar, Radek Podgorny,
linux-kernel, linux-hardening
The "early" part of the helper's name isn't accurate[1]. Drop it in
preparation for adding a new (not early) usage.
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/lkml/CAMj1kXEyDjH0uu3Z4eBesV3PEnKGi5ArXXMp7R-hn8HdRytiPg@mail.gmail.com [1]
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Baskov Evgeniy <baskov@ispras.ru>
Cc: linux-efi@vger.kernel.org
---
drivers/firmware/efi/libstub/relocate.c | 2 +-
drivers/firmware/efi/libstub/unaccepted_memory.c | 2 +-
drivers/firmware/efi/libstub/x86-stub.c | 2 +-
include/linux/efi.h | 4 ++--
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/firmware/efi/libstub/relocate.c b/drivers/firmware/efi/libstub/relocate.c
index bf6fbd5d22a1..d694bcfa1074 100644
--- a/drivers/firmware/efi/libstub/relocate.c
+++ b/drivers/firmware/efi/libstub/relocate.c
@@ -48,7 +48,7 @@ efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
unsigned long m = (unsigned long)map->map;
u64 start, end;
- desc = efi_early_memdesc_ptr(m, map->desc_size, i);
+ desc = efi_memdesc_ptr(m, map->desc_size, i);
if (desc->type != EFI_CONVENTIONAL_MEMORY)
continue;
diff --git a/drivers/firmware/efi/libstub/unaccepted_memory.c b/drivers/firmware/efi/libstub/unaccepted_memory.c
index 9a655f30ba47..c295ea3a6efc 100644
--- a/drivers/firmware/efi/libstub/unaccepted_memory.c
+++ b/drivers/firmware/efi/libstub/unaccepted_memory.c
@@ -29,7 +29,7 @@ efi_status_t allocate_unaccepted_bitmap(__u32 nr_desc,
efi_memory_desc_t *d;
unsigned long m = (unsigned long)map->map;
- d = efi_early_memdesc_ptr(m, map->desc_size, i);
+ d = efi_memdesc_ptr(m, map->desc_size, i);
if (d->type != EFI_UNACCEPTED_MEMORY)
continue;
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 1983fd3bf392..8d94484f3a20 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -555,7 +555,7 @@ setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_s
m |= (u64)efi->efi_memmap_hi << 32;
#endif
- d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
+ d = efi_memdesc_ptr(m, efi->efi_memdesc_size, i);
switch (d->type) {
case EFI_RESERVED_TYPE:
case EFI_RUNTIME_SERVICES_CODE:
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 418e555459da..fbdfcc9a81e6 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -783,7 +783,7 @@ extern int efi_memattr_apply_permissions(struct mm_struct *mm,
efi_memattr_perm_setter fn);
/*
- * efi_early_memdesc_ptr - get the n-th EFI memmap descriptor
+ * efi_memdesc_ptr - get the n-th EFI memmap descriptor
* @map: the start of efi memmap
* @desc_size: the size of space for each EFI memmap descriptor
* @n: the index of efi memmap descriptor
@@ -801,7 +801,7 @@ extern int efi_memattr_apply_permissions(struct mm_struct *mm,
* during bootup since for_each_efi_memory_desc_xxx() is available after the
* kernel initializes the EFI subsystem to set up struct efi_memory_map.
*/
-#define efi_early_memdesc_ptr(map, desc_size, n) \
+#define efi_memdesc_ptr(map, desc_size, n) \
(efi_memory_desc_t *)((void *)(map) + ((n) * (desc_size)))
/* Iterate through an efi_memory_map */
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2 2/2] efi: Replace efi_memory_attributes_table_t 0-sized array with flexible array
2024-07-11 17:11 [PATCH v2 0/2] efi: Replace efi_memory_attributes_table_t 0-sized array with flexible array Kees Cook
2024-07-11 17:11 ` [PATCH v2 1/2] efi: Rename efi_early_memdesc_ptr() to efi_memdesc_ptr() Kees Cook
@ 2024-07-11 17:11 ` Kees Cook
2024-07-12 8:08 ` [PATCH v2 0/2] " Ard Biesheuvel
2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2024-07-11 17:11 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Kees Cook, linux-efi, Kirill A. Shutemov, Borislav Petkov (AMD),
Baskov Evgeniy, Ingo Molnar, Radek Podgorny, linux-kernel,
linux-hardening
While efi_memory_attributes_table_t::entry isn't used directly as an
array, it is used as a base for pointer arithmetic. The type is wrong
as it's not technically an array of efi_memory_desc_t's; they could be
larger. Regardless, leave the type unchanged and remove the old style
"0" array size. Additionally replace the open-coded entry offset code
with the existing efi_memdesc_ptr() helper.
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
---
drivers/firmware/efi/memattr.c | 2 +-
include/linux/efi.h | 6 +++++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c
index ab85bf8e165a..164203429fa7 100644
--- a/drivers/firmware/efi/memattr.c
+++ b/drivers/firmware/efi/memattr.c
@@ -164,7 +164,7 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm,
bool valid;
char buf[64];
- valid = entry_is_valid((void *)tbl->entry + i * tbl->desc_size,
+ valid = entry_is_valid(efi_memdesc_ptr(tbl->entry, tbl->desc_size, i),
&md);
size = md.num_pages << EFI_PAGE_SHIFT;
if (efi_enabled(EFI_DBG) || !valid)
diff --git a/include/linux/efi.h b/include/linux/efi.h
index fbdfcc9a81e6..40475d77231c 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -607,7 +607,11 @@ typedef struct {
u32 num_entries;
u32 desc_size;
u32 flags;
- efi_memory_desc_t entry[0];
+ /*
+ * There are @num_entries following, each of size @desc_size bytes,
+ * including an efi_memory_desc_t header. See efi_memdesc_ptr().
+ */
+ efi_memory_desc_t entry[];
} efi_memory_attributes_table_t;
typedef struct {
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread