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| author | Ard Biesheuvel <ardb@kernel.org> | 2023-02-01 09:48:12 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2023-02-04 09:19:02 +0100 |
| commit | cf1d2ffcc6f17b422239f6ab34b078945d07f9aa (patch) | |
| tree | a42d8efe5cc90616ea052bbbe84dfaad91b9f5a1 /drivers/firmware | |
| parent | b0048092f7d3921d56f2c5bfa32062fac5e7500b (diff) | |
| download | linux-cf1d2ffcc6f17b422239f6ab34b078945d07f9aa.tar.gz linux-cf1d2ffcc6f17b422239f6ab34b078945d07f9aa.tar.bz2 linux-cf1d2ffcc6f17b422239f6ab34b078945d07f9aa.zip | |
efi: Discover BTI support in runtime services regions
Add the generic plumbing to detect whether or not the runtime code
regions were constructed with BTI/IBT landing pads by the firmware,
permitting the OS to enable enforcement when mapping these regions into
the OS's address space.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/memattr.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c index 0a9aba5f9cef..3cbf00f04c5b 100644 --- a/drivers/firmware/efi/memattr.c +++ b/drivers/firmware/efi/memattr.c @@ -129,6 +129,7 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm, efi_memattr_perm_setter fn) { efi_memory_attributes_table_t *tbl; + bool has_bti = false; int i, ret; if (tbl_size <= sizeof(*tbl)) @@ -150,6 +151,10 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm, return -ENOMEM; } + if (tbl->version > 1 && + (tbl->flags & EFI_MEMORY_ATTRIBUTES_FLAGS_RT_FORWARD_CONTROL_FLOW_GUARD)) + has_bti = true; + if (efi_enabled(EFI_DBG)) pr_info("Processing EFI Memory Attributes table:\n"); @@ -169,7 +174,7 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm, efi_md_typeattr_format(buf, sizeof(buf), &md)); if (valid) { - ret = fn(mm, &md); + ret = fn(mm, &md, has_bti); if (ret) pr_err("Error updating mappings, skipping subsequent md's\n"); } |