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arm64: entry: Allow the trampoline text to occupy multiple pages

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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>
This commit is contained in:
James Morse 2021-11-18 15:04:32 +00:00
parent c47e4d04ba
commit a9c406e646
5 changed files with 20 additions and 7 deletions
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6
arch/arm64/include/asm/fixmap.h
View File

@ -62,9 +62,11 @@ 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,

5
arch/arm64/include/asm/sections.h
View File

@ -23,4 +23,9 @@ extern char __mmuoff_data_start[], __mmuoff_data_end[];
extern char __entry_tramp_text_start[], __entry_tramp_text_end[];
extern char __relocate_new_kernel_start[], __relocate_new_kernel_end[];
static inline size_t entry_tramp_text_size(void)
{
return __entry_tramp_text_end - __entry_tramp_text_start;
}
#endif /* __ASM_SECTIONS_H */

2
arch/arm64/kernel/entry.S
View File

@ -642,7 +642,7 @@ 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

2
arch/arm64/kernel/vmlinux.lds.S
View File

@ -341,7 +341,7 @@ 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
#ifdef CONFIG_KVM

12
arch/arm64/mm/mmu.c
View File

@ -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[];