From: James Morse james.morse@arm.com
commit a9c406e6462ff14956d690de7bbe5131a5677dc9 upstream.
Adding a second set of vectors to .entry.tramp.text will make it larger than a single 4K page.
Allow the trampoline text to occupy up to three pages by adding two more fixmap slots. Previous changes to tramp_valias allowed it to reach beyond a single page.
Reviewed-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: James Morse james.morse@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/include/asm/fixmap.h | 6 ++++-- arch/arm64/include/asm/sections.h | 5 +++++ arch/arm64/kernel/entry.S | 2 +- arch/arm64/kernel/vmlinux.lds.S | 2 +- arch/arm64/mm/mmu.c | 12 +++++++++--- 5 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h index 2e0977c7564c..928a96b9b161 100644 --- a/arch/arm64/include/asm/fixmap.h +++ b/arch/arm64/include/asm/fixmap.h @@ -63,9 +63,11 @@ enum fixed_addresses { #endif /* CONFIG_ACPI_APEI_GHES */
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 - FIX_ENTRY_TRAMP_TEXT, + FIX_ENTRY_TRAMP_TEXT3, + FIX_ENTRY_TRAMP_TEXT2, + FIX_ENTRY_TRAMP_TEXT1, FIX_ENTRY_TRAMP_DATA, -#define TRAMP_VALIAS (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT)) +#define TRAMP_VALIAS (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT1)) #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ __end_of_permanent_fixed_addresses,
diff --git a/arch/arm64/include/asm/sections.h b/arch/arm64/include/asm/sections.h index 25a73aab438f..a75f2882cc7c 100644 --- a/arch/arm64/include/asm/sections.h +++ b/arch/arm64/include/asm/sections.h @@ -20,4 +20,9 @@ extern char __irqentry_text_start[], __irqentry_text_end[]; extern char __mmuoff_data_start[], __mmuoff_data_end[]; extern char __entry_tramp_text_start[], __entry_tramp_text_end[];
+static inline size_t entry_tramp_text_size(void) +{ + return __entry_tramp_text_end - __entry_tramp_text_start; +} + #endif /* __ASM_SECTIONS_H */ diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index bb456f596c43..c1cebaf68e0c 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -1059,7 +1059,7 @@ alternative_else_nop_endif .endm
.macro tramp_data_page dst - adr \dst, .entry.tramp.text + adr_l \dst, .entry.tramp.text sub \dst, \dst, PAGE_SIZE .endm
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 1f82cf631c3c..fbab044b3a39 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -276,7 +276,7 @@ ASSERT(__hibernate_exit_text_end - (__hibernate_exit_text_start & ~(SZ_4K - 1)) <= SZ_4K, "Hibernate exit text too big or misaligned") #endif #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) == PAGE_SIZE, +ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) <= 3*PAGE_SIZE, "Entry trampoline text too big") #endif /* diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 99bc0289ab2b..5cf575f23af2 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -583,6 +583,8 @@ early_param("rodata", parse_rodata); #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 static int __init map_entry_trampoline(void) { + int i; + pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start);
@@ -591,11 +593,15 @@ static int __init map_entry_trampoline(void)
/* Map only the text into the trampoline page table */ memset(tramp_pg_dir, 0, PGD_SIZE); - __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, - prot, __pgd_pgtable_alloc, 0); + __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, + entry_tramp_text_size(), prot, + __pgd_pgtable_alloc, NO_BLOCK_MAPPINGS);
/* Map both the text and data into the kernel page table */ - __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot); + for (i = 0; i < DIV_ROUND_UP(entry_tramp_text_size(), PAGE_SIZE); i++) + __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i, + pa_start + i * PAGE_SIZE, prot); + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { extern char __entry_tramp_data_start[];