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authorJames Morse <james.morse@arm.com>2021-11-18 16:04:32 +0100
committerJames Morse <james.morse@arm.com>2022-02-15 18:40:28 +0100
commita9c406e6462ff14956d690de7bbe5131a5677dc9 (patch)
tree90b8435c09994d03fff2d8d26d131c503efdd700 /arch/arm64/mm/mmu.c
parentarm64: entry: Make the kpti trampoline's kpti sequence optional (diff)
downloadlinux-a9c406e6462ff14956d690de7bbe5131a5677dc9.tar.xz
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arm64: entry: Allow the trampoline text to occupy multiple pages
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>
Diffstat (limited to 'arch/arm64/mm/mmu.c')
-rw-r--r--arch/arm64/mm/mmu.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index acfae9b41cc8..49abbf43bf35 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -617,6 +617,8 @@ 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);
@@ -625,11 +627,15 @@ 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[];