Commit-ID: 05dd61fa7ff73678c33d252aa9f989634349c791 Gitweb: http://git.kernel.org/tip/05dd61fa7ff73678c33d252aa9f989634349c791 Author: Andy Lutomirski <l...@kernel.org> AuthorDate: Tue, 4 Apr 2017 17:02:36 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 5 Apr 2017 09:27:48 +0200
x86/efi: Clean up the EFI CR3 save/restore logic efi_call_phys_prolog() used to return a "pgd_t *" that meant one of three different things depending on kernel and system configuration. Clean it up so it uses a union and is more explicit about what's going on. Signed-off-by: Andy Lutomirski <l...@kernel.org> Signed-off-by: Matt Fleming <m...@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: linux-...@vger.kernel.org Link: http://lkml.kernel.org/r/20170404160245.27812-3-ard.biesheu...@linaro.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/include/asm/efi.h | 17 +++++++++++++++-- arch/x86/platform/efi/efi.c | 6 +++--- arch/x86/platform/efi/efi_32.c | 12 ++++++------ arch/x86/platform/efi/efi_64.c | 22 ++++++++++++---------- 4 files changed, 36 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 2f77bce..0859ed7 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -111,11 +111,24 @@ extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size, #endif /* CONFIG_X86_32 */ +union efi_saved_pgd { + /* + * If !EFI_OLD_MEMMAP or we're 32-bit, this is a verbatim saved CR3 + * value: + */ + unsigned long cr3; + +#ifdef CONFIG_X86_64 + /* If EFI_OLD_MEMMAP, this is a kmalloc()ed copy of the pgd: */ + pgd_t *pgd; +#endif +}; + extern struct efi_scratch efi_scratch; extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable); extern int __init efi_memblock_x86_reserve_range(void); -extern pgd_t * __init efi_call_phys_prolog(void); -extern void __init efi_call_phys_epilog(pgd_t *save_pgd); +extern union efi_saved_pgd __init efi_call_phys_prolog(void); +extern void __init efi_call_phys_epilog(union efi_saved_pgd saved_pgd); extern void __init efi_print_memmap(void); extern void __init efi_memory_uc(u64 addr, unsigned long size); extern void __init efi_map_region(efi_memory_desc_t *md); diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 565dff3..217dc16 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -81,9 +81,9 @@ static efi_status_t __init phys_efi_set_virtual_address_map( { efi_status_t status; unsigned long flags; - pgd_t *save_pgd; + union efi_saved_pgd saved_pgd; - save_pgd = efi_call_phys_prolog(); + saved_pgd = efi_call_phys_prolog(); /* Disable interrupts around EFI calls: */ local_irq_save(flags); @@ -92,7 +92,7 @@ static efi_status_t __init phys_efi_set_virtual_address_map( descriptor_version, virtual_map); local_irq_restore(flags); - efi_call_phys_epilog(save_pgd); + efi_call_phys_epilog(saved_pgd); return status; } diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c index cef39b0..9b1abcf 100644 --- a/arch/x86/platform/efi/efi_32.c +++ b/arch/x86/platform/efi/efi_32.c @@ -58,13 +58,13 @@ void __init efi_map_region(efi_memory_desc_t *md) void __init efi_map_region_fixed(efi_memory_desc_t *md) {} void __init parse_efi_setup(u64 phys_addr, u32 data_len) {} -pgd_t * __init efi_call_phys_prolog(void) +union efi_saved_pgd __init efi_call_phys_prolog(void) { struct desc_ptr gdt_descr; - pgd_t *save_pgd; + union efi_saved_pgd saved_pgd; /* Current pgd is swapper_pg_dir, we'll restore it later: */ - save_pgd = swapper_pg_dir; + saved_pgd.cr3 = __pa(swapper_pg_dir); load_cr3(initial_page_table); __flush_tlb_all(); @@ -72,10 +72,10 @@ pgd_t * __init efi_call_phys_prolog(void) gdt_descr.size = GDT_SIZE - 1; load_gdt(&gdt_descr); - return save_pgd; + return saved_pgd; } -void __init efi_call_phys_epilog(pgd_t *save_pgd) +void __init efi_call_phys_epilog(union efi_saved_pgd saved_pgd) { struct desc_ptr gdt_descr; @@ -83,7 +83,7 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) gdt_descr.size = GDT_SIZE - 1; load_gdt(&gdt_descr); - load_cr3(save_pgd); + write_cr3(saved_pgd.cr3); __flush_tlb_all(); } diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index a4695da..d56dd864 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -69,16 +69,16 @@ static void __init early_code_mapping_set_exec(int executable) } } -pgd_t * __init efi_call_phys_prolog(void) +union efi_saved_pgd __init efi_call_phys_prolog(void) { unsigned long vaddress; - pgd_t *save_pgd; + union efi_saved_pgd saved_pgd; int pgd; int n_pgds; if (!efi_enabled(EFI_OLD_MEMMAP)) { - save_pgd = (pgd_t *)read_cr3(); + saved_pgd.cr3 = read_cr3(); write_cr3((unsigned long)efi_scratch.efi_pgt); goto out; } @@ -86,20 +86,21 @@ pgd_t * __init efi_call_phys_prolog(void) early_code_mapping_set_exec(1); n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE); - save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL); + saved_pgd.pgd = kmalloc_array(n_pgds, sizeof(*saved_pgd.pgd), + GFP_KERNEL); for (pgd = 0; pgd < n_pgds; pgd++) { - save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE); + saved_pgd.pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE); vaddress = (unsigned long)__va(pgd * PGDIR_SIZE); set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress)); } out: __flush_tlb_all(); - return save_pgd; + return saved_pgd; } -void __init efi_call_phys_epilog(pgd_t *save_pgd) +void __init efi_call_phys_epilog(union efi_saved_pgd saved_pgd) { /* * After the lock is released, the original page table is restored. @@ -108,7 +109,7 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) int nr_pgds; if (!efi_enabled(EFI_OLD_MEMMAP)) { - write_cr3((unsigned long)save_pgd); + write_cr3(saved_pgd.cr3); __flush_tlb_all(); return; } @@ -116,9 +117,10 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE); for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) - set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]); + set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), + saved_pgd.pgd[pgd_idx]); - kfree(save_pgd); + kfree(saved_pgd.pgd); __flush_tlb_all(); early_code_mapping_set_exec(0);
