From: James Morse <james.morse@arm.com>
To: stable@vger.kernel.org
Cc: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org,
james.morse@arm.com
Subject: [stable:PATCH v5.4.184 13/22] arm64: entry: Allow the trampoline text to occupy multiple pages
Date: Tue, 15 Mar 2022 18:24:06 +0000 [thread overview]
Message-ID: <20220315182415.3900464-14-james.morse@arm.com> (raw)
In-Reply-To: <20220315182415.3900464-1-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>
---
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[];
--
2.30.2
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next prev parent reply other threads:[~2022-03-15 18:29 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 18:23 [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 01/22] arm64: Add part number for Arm Cortex-A77 James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 02/22] arm64: Add Neoverse-N2, Cortex-A710 CPU part definition James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 03/22] arm64: add ID_AA64ISAR2_EL1 sys register James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 04/22] arm64: Add Cortex-X2 CPU part definition James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 05/22] arm64: entry.S: Add ventry overflow sanity checks James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 06/22] arm64: entry: Make the trampoline cleanup optional James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 07/22] arm64: entry: Free up another register on kpti's tramp_exit path James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 08/22] arm64: entry: Move the trampoline data page before the text page James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 09/22] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 10/22] arm64: entry: Don't assume tramp_vectors is the start of the vectors James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 11/22] arm64: entry: Move trampoline macros out of ifdef'd section James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 12/22] arm64: entry: Make the kpti trampoline's kpti sequence optional James Morse
2022-03-15 18:24 ` James Morse [this message]
2022-03-15 18:24 ` [stable:PATCH v5.4.184 14/22] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 15/22] arm64: entry: Add vectors that have the bhb mitigation sequences James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 16/22] arm64: entry: Add macro for reading symbol addresses from the trampoline James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 17/22] arm64: Add percpu vectors for EL1 James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 18/22] arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 19/22] KVM: arm64: Add templates for BHB mitigation sequences James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 20/22] arm64: Mitigate spectre style branch history side channels James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 21/22] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 22/22] arm64: Use the clearbhb instruction in mitigations James Morse
2022-03-16 15:41 ` [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels Sasha Levin
2022-03-16 17:38 ` James Morse
2022-03-16 18:43 ` Sasha Levin
2022-03-17 10:00 ` Greg KH
2022-03-18 12:15 ` James Morse
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