Convert kernel_add_identity_map() into a function pointer to be able to provide alternative implementations of this function. Required to enable calling the code using this function from EFI environment. Tested-by: Mario Limonciello <mario.limonciello@xxxxxxx> Signed-off-by: Evgeniy Baskov <baskov@xxxxxxxxx> Warnings on the previous version were Reported-by: kernel test robot <lkp@xxxxxxxxx> Link: https://lore.kernel.org/oe-kbuild-all/202303090348.l0pqa8oz-lkp@xxxxxxxxx/ --- arch/x86/boot/compressed/ident_map_64.c | 7 ++++--- arch/x86/boot/compressed/misc.c | 24 ++++++++++++++++++++++++ arch/x86/boot/compressed/misc.h | 15 +++------------ 3 files changed, 31 insertions(+), 15 deletions(-) diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index 378f99b1d7e8..1995560d3b43 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -92,9 +92,9 @@ bool has_nx; /* set in head_64.S */ /* * Adds the specified range to the identity mappings. */ -unsigned long kernel_add_identity_map(unsigned long start, - unsigned long end, - unsigned int flags) +static unsigned long kernel_add_identity_map_impl(unsigned long start, + unsigned long end, + unsigned int flags) { int ret; @@ -143,6 +143,7 @@ void initialize_identity_maps(void *rmode) struct setup_data *sd; boot_params = rmode; + kernel_add_identity_map = kernel_add_identity_map_impl; /* Exclude the encryption mask from __PHYSICAL_MASK */ physical_mask &= ~sme_me_mask; diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 76773a989364..74f028cf2dfd 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -277,6 +277,22 @@ static size_t parse_elf(void *output, unsigned long output_len, return ehdr.e_entry - LOAD_PHYSICAL_ADDR; } +/* + * This points to actual implementation of mapping function + * for current environment: either EFI API wrapper, + * own implementation or dummy implementation below. + */ +unsigned long (*kernel_add_identity_map)(unsigned long start, + unsigned long end, + unsigned int flags); + +static unsigned long kernel_add_identity_map_dummy(unsigned long start, + unsigned long end, + unsigned int flags) +{ + return start; +} + /* * The compressed kernel image (ZO), has been moved so that its position * is against the end of the buffer used to hold the uncompressed kernel @@ -315,6 +331,14 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, init_default_io_ops(); + /* + * On 64-bit this pointer is set during page table uninitialization, + * but on 32-bit it remains uninitialized, since paging is disabled. + */ + if (IS_ENABLED(CONFIG_X86_32)) + kernel_add_identity_map = kernel_add_identity_map_dummy; + + /* * Detect TDX guest environment. * diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index e20f60bfe91b..fe201b45b038 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -182,18 +182,9 @@ static inline int count_immovable_mem_regions(void) { return 0; } #ifdef CONFIG_X86_5LEVEL extern unsigned int __pgtable_l5_enabled, pgdir_shift, ptrs_per_p4d; #endif -#ifdef CONFIG_X86_64 -extern unsigned long kernel_add_identity_map(unsigned long start, - unsigned long end, - unsigned int flags); -#else -static inline unsigned long kernel_add_identity_map(unsigned long start, - unsigned long end, - unsigned int flags) -{ - return start; -} -#endif +extern unsigned long (*kernel_add_identity_map)(unsigned long start, + unsigned long end, + unsigned int flags); /* Used by PAGE_KERN* macros: */ extern pteval_t __default_kernel_pte_mask; -- 2.39.2
