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From foo@baz Tue Mar 8 08:47:19 PM CET 2022 |
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From: James Morse <james.morse@arm.com> |
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Date: Thu, 18 Nov 2021 15:04:32 +0000 |
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Subject: arm64: entry: Allow the trampoline text to occupy multiple pages |
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|
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From: James Morse <james.morse@arm.com> |
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|
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commit a9c406e6462ff14956d690de7bbe5131a5677dc9 upstream. |
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|
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Adding a second set of vectors to .entry.tramp.text will make it |
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larger than a single 4K page. |
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|
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Allow the trampoline text to occupy up to three pages by adding two |
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more fixmap slots. Previous changes to tramp_valias allowed it to reach |
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beyond a single page. |
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|
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Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> |
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Signed-off-by: James Morse <james.morse@arm.com> |
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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--- |
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arch/arm64/include/asm/fixmap.h | 6 ++++-- |
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arch/arm64/include/asm/sections.h | 5 +++++ |
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arch/arm64/kernel/entry.S | 2 +- |
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arch/arm64/kernel/vmlinux.lds.S | 2 +- |
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arch/arm64/mm/mmu.c | 12 +++++++++--- |
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5 files changed, 20 insertions(+), 7 deletions(-) |
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|
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--- a/arch/arm64/include/asm/fixmap.h |
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+++ b/arch/arm64/include/asm/fixmap.h |
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@@ -62,9 +62,11 @@ enum fixed_addresses { |
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#endif /* CONFIG_ACPI_APEI_GHES */ |
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|
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#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 |
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- FIX_ENTRY_TRAMP_TEXT, |
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+ FIX_ENTRY_TRAMP_TEXT3, |
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+ FIX_ENTRY_TRAMP_TEXT2, |
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+ FIX_ENTRY_TRAMP_TEXT1, |
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FIX_ENTRY_TRAMP_DATA, |
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-#define TRAMP_VALIAS (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT)) |
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+#define TRAMP_VALIAS (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT1)) |
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#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ |
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__end_of_permanent_fixed_addresses, |
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|
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--- a/arch/arm64/include/asm/sections.h |
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+++ b/arch/arm64/include/asm/sections.h |
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@@ -22,4 +22,9 @@ extern char __irqentry_text_start[], __i |
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extern char __mmuoff_data_start[], __mmuoff_data_end[]; |
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extern char __entry_tramp_text_start[], __entry_tramp_text_end[]; |
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|
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+static inline size_t entry_tramp_text_size(void) |
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+{ |
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+ return __entry_tramp_text_end - __entry_tramp_text_start; |
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+} |
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+ |
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#endif /* __ASM_SECTIONS_H */ |
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--- a/arch/arm64/kernel/entry.S |
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+++ b/arch/arm64/kernel/entry.S |
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@@ -642,7 +642,7 @@ alternative_else_nop_endif |
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.endm |
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|
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.macro tramp_data_page dst |
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- adr \dst, .entry.tramp.text |
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+ adr_l \dst, .entry.tramp.text |
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sub \dst, \dst, PAGE_SIZE |
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.endm |
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|
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--- a/arch/arm64/kernel/vmlinux.lds.S |
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+++ b/arch/arm64/kernel/vmlinux.lds.S |
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@@ -330,7 +330,7 @@ ASSERT(__hibernate_exit_text_end - (__hi |
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<= SZ_4K, "Hibernate exit text too big or misaligned") |
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#endif |
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#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 |
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-ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) == PAGE_SIZE, |
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+ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) <= 3*PAGE_SIZE, |
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"Entry trampoline text too big") |
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#endif |
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#ifdef CONFIG_KVM |
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--- a/arch/arm64/mm/mmu.c |
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+++ b/arch/arm64/mm/mmu.c |
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@@ -616,6 +616,8 @@ early_param("rodata", parse_rodata); |
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#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 |
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static int __init map_entry_trampoline(void) |
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{ |
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+ int i; |
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+ |
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pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; |
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phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start); |
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|
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@@ -624,11 +626,15 @@ static int __init map_entry_trampoline(v |
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|
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/* Map only the text into the trampoline page table */ |
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memset(tramp_pg_dir, 0, PGD_SIZE); |
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- __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, |
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- prot, __pgd_pgtable_alloc, 0); |
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+ __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, |
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+ entry_tramp_text_size(), prot, |
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+ __pgd_pgtable_alloc, NO_BLOCK_MAPPINGS); |
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|
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/* Map both the text and data into the kernel page table */ |
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- __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot); |
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+ for (i = 0; i < DIV_ROUND_UP(entry_tramp_text_size(), PAGE_SIZE); i++) |
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+ __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i, |
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+ pa_start + i * PAGE_SIZE, prot); |
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+ |
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if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { |
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extern char __entry_tramp_data_start[]; |
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