| From foo@baz Sat Mar 19 01:51:18 PM CET 2022 |
| From: James Morse <james.morse@arm.com> |
| Date: Fri, 18 Mar 2022 17:48:32 +0000 |
| Subject: arm64: entry: Allow the trampoline text to occupy multiple pages |
| To: stable@vger.kernel.org |
| Cc: linux-kernel@vger.kernel.org, james.morse@arm.com, catalin.marinas@arm.com |
| Message-ID: <20220318174842.2321061-13-james.morse@arm.com> |
| |
| 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: Greg Kroah-Hartman <gregkh@linuxfoundation.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(-) |
| |
| --- a/arch/arm64/include/asm/fixmap.h |
| +++ b/arch/arm64/include/asm/fixmap.h |
| @@ -59,9 +59,11 @@ 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, |
| |
| --- a/arch/arm64/include/asm/sections.h |
| +++ b/arch/arm64/include/asm/sections.h |
| @@ -30,4 +30,9 @@ extern char __irqentry_text_start[], __i |
| 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 */ |
| --- a/arch/arm64/kernel/entry.S |
| +++ b/arch/arm64/kernel/entry.S |
| @@ -966,7 +966,7 @@ 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 |
| |
| --- a/arch/arm64/kernel/vmlinux.lds.S |
| +++ b/arch/arm64/kernel/vmlinux.lds.S |
| @@ -259,7 +259,7 @@ ASSERT(__hibernate_exit_text_end - (__hi |
| <= 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 |
| /* |
| --- a/arch/arm64/mm/mmu.c |
| +++ b/arch/arm64/mm/mmu.c |
| @@ -541,6 +541,8 @@ 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); |
| |
| @@ -549,11 +551,15 @@ static int __init map_entry_trampoline(v |
| |
| /* 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, |
| + 0); |
| |
| /* 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[]; |
| |