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arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors

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Users of trans_pgd may also need a copy of vector table because it is
also may be overwritten if a linear map can be overwritten.

Move setup of EL2 vectors from hibernate to trans_pgd, so it can be
later shared with kexec as well.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-3-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Pasha Tatashin 2021-09-30 14:31:00 +00:00 committed by Will Deacon
parent 094a3684b9
commit 788bfdd974
7 changed files with 103 additions and 72 deletions
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9
arch/arm64/include/asm/trans_pgd.h
View file

@ -1,8 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2020, Microsoft Corporation.
* Pavel Tatashin <pasha.tatashin@soleen.com>
* Copyright (c) 2021, Microsoft Corporation.
* Pasha Tatashin <pasha.tatashin@soleen.com>
*/
#ifndef _ASM_TRANS_TABLE_H
@ -36,4 +36,9 @@ int trans_pgd_map_page(struct trans_pgd_info *info, pgd_t *trans_pgd,
int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
unsigned long *t0sz, void *page);
int trans_pgd_copy_el2_vectors(struct trans_pgd_info *info,
phys_addr_t *el2_vectors);
extern char trans_pgd_stub_vectors[];
#endif /* _ASM_TRANS_TABLE_H */

2
arch/arm64/include/asm/virt.h
View file

@ -67,6 +67,8 @@
*/
extern u32 __boot_cpu_mode[2];
#define ARM64_VECTOR_TABLE_LEN SZ_2K
void __hyp_set_vectors(phys_addr_t phys_vector_base);
void __hyp_reset_vectors(void);

52
arch/arm64/kernel/hibernate-asm.S
View file

@ -112,56 +112,4 @@ alternative_insn "dc cvau, x4", "dc civac, x4", ARM64_WORKAROUND_CLEAN_CACHE
hvc #0
3: ret
SYM_CODE_END(swsusp_arch_suspend_exit)
/*
* Restore the hyp stub.
* This must be done before the hibernate page is unmapped by _cpu_resume(),
* but happens before any of the hyp-stub's code is cleaned to PoC.
*
* x24: The physical address of __hyp_stub_vectors
*/
SYM_CODE_START_LOCAL(el1_sync)
msr vbar_el2, x24
eret
SYM_CODE_END(el1_sync)
.macro invalid_vector label
SYM_CODE_START_LOCAL(\label)
b \label
SYM_CODE_END(\label)
.endm
invalid_vector el2_sync_invalid
invalid_vector el2_irq_invalid
invalid_vector el2_fiq_invalid
invalid_vector el2_error_invalid
invalid_vector el1_sync_invalid
invalid_vector el1_irq_invalid
invalid_vector el1_fiq_invalid
invalid_vector el1_error_invalid
/* el2 vectors - switch el2 here while we restore the memory image. */
.align 11
SYM_CODE_START(hibernate_el2_vectors)
ventry el2_sync_invalid // Synchronous EL2t
ventry el2_irq_invalid // IRQ EL2t
ventry el2_fiq_invalid // FIQ EL2t
ventry el2_error_invalid // Error EL2t
ventry el2_sync_invalid // Synchronous EL2h
ventry el2_irq_invalid // IRQ EL2h
ventry el2_fiq_invalid // FIQ EL2h
ventry el2_error_invalid // Error EL2h
ventry el1_sync // Synchronous 64-bit EL1
ventry el1_irq_invalid // IRQ 64-bit EL1
ventry el1_fiq_invalid // FIQ 64-bit EL1
ventry el1_error_invalid // Error 64-bit EL1
ventry el1_sync_invalid // Synchronous 32-bit EL1
ventry el1_irq_invalid // IRQ 32-bit EL1
ventry el1_fiq_invalid // FIQ 32-bit EL1
ventry el1_error_invalid // Error 32-bit EL1
SYM_CODE_END(hibernate_el2_vectors)
.popsection

26
arch/arm64/kernel/hibernate.c
View file

@ -51,9 +51,6 @@ extern int in_suspend;
/* Do we need to reset el2? */
#define el2_reset_needed() (is_hyp_nvhe())
/* temporary el2 vectors in the __hibernate_exit_text section. */
extern char hibernate_el2_vectors[];
/* hyp-stub vectors, used to restore el2 during resume from hibernate. */
extern char __hyp_stub_vectors[];
@ -434,6 +431,7 @@ int swsusp_arch_resume(void)
void *zero_page;
size_t exit_size;
pgd_t *tmp_pg_dir;
phys_addr_t el2_vectors;
void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *,
void *, phys_addr_t, phys_addr_t);
struct trans_pgd_info trans_info = {
@ -461,6 +459,14 @@ int swsusp_arch_resume(void)
return -ENOMEM;
}
if (el2_reset_needed()) {
rc = trans_pgd_copy_el2_vectors(&trans_info, &el2_vectors);
if (rc) {
pr_err("Failed to setup el2 vectors\n");
return rc;
}
}
exit_size = __hibernate_exit_text_end - __hibernate_exit_text_start;
/*
* Copy swsusp_arch_suspend_exit() to a safe page. This will generate
@ -473,26 +479,14 @@ int swsusp_arch_resume(void)
return rc;
}
/*
* The hibernate exit text contains a set of el2 vectors, that will
* be executed at el2 with the mmu off in order to reload hyp-stub.
*/
dcache_clean_inval_poc((unsigned long)hibernate_exit,
(unsigned long)hibernate_exit + exit_size);
/*
* KASLR will cause the el2 vectors to be in a different location in
* the resumed kernel. Load hibernate's temporary copy into el2.
*
* We can skip this step if we booted at EL1, or are running with VHE.
*/
if (el2_reset_needed()) {
phys_addr_t el2_vectors = (phys_addr_t)hibernate_exit;
el2_vectors += hibernate_el2_vectors -
__hibernate_exit_text_start; /* offset */
if (el2_reset_needed())
__hyp_set_vectors(el2_vectors);
}
hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
resume_hdr.reenter_kernel, restore_pblist,

1
arch/arm64/mm/Makefile
View file

@ -7,6 +7,7 @@ obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o
obj-$(CONFIG_TRANS_TABLE) += trans_pgd.o
obj-$(CONFIG_TRANS_TABLE) += trans_pgd-asm.o
obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
obj-$(CONFIG_ARM64_MTE) += mteswap.o
KASAN_SANITIZE_physaddr.o += n

58
arch/arm64/mm/trans_pgd-asm.S Normal file
View file

@ -0,0 +1,58 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2021, Microsoft Corporation.
* Pasha Tatashin <pasha.tatashin@soleen.com>
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/kvm_asm.h>
.macro invalid_vector label
SYM_CODE_START_LOCAL(\label)
.align 7
b \label
SYM_CODE_END(\label)
.endm
.macro el1_sync_vector
SYM_CODE_START_LOCAL(el1_sync)
.align 7
cmp x0, #HVC_SET_VECTORS /* Called from hibernate */
b.ne 1f
msr vbar_el2, x1
mov x0, xzr
eret
1: /* Unexpected argument, set an error */
mov_q x0, HVC_STUB_ERR
eret
SYM_CODE_END(el1_sync)
.endm
SYM_CODE_START(trans_pgd_stub_vectors)
invalid_vector hyp_stub_el2t_sync_invalid // Synchronous EL2t
invalid_vector hyp_stub_el2t_irq_invalid // IRQ EL2t
invalid_vector hyp_stub_el2t_fiq_invalid // FIQ EL2t
invalid_vector hyp_stub_el2t_error_invalid // Error EL2t
invalid_vector hyp_stub_el2h_sync_invalid // Synchronous EL2h
invalid_vector hyp_stub_el2h_irq_invalid // IRQ EL2h
invalid_vector hyp_stub_el2h_fiq_invalid // FIQ EL2h
invalid_vector hyp_stub_el2h_error_invalid // Error EL2h
el1_sync_vector // Synchronous 64-bit EL1
invalid_vector hyp_stub_el1_irq_invalid // IRQ 64-bit EL1
invalid_vector hyp_stub_el1_fiq_invalid // FIQ 64-bit EL1
invalid_vector hyp_stub_el1_error_invalid // Error 64-bit EL1
invalid_vector hyp_stub_32b_el1_sync_invalid // Synchronous 32-bit EL1
invalid_vector hyp_stub_32b_el1_irq_invalid // IRQ 32-bit EL1
invalid_vector hyp_stub_32b_el1_fiq_invalid // FIQ 32-bit EL1
invalid_vector hyp_stub_32b_el1_error_invalid // Error 32-bit EL1
.align 11
SYM_INNER_LABEL(__trans_pgd_stub_vectors_end, SYM_L_LOCAL)
SYM_CODE_END(trans_pgd_stub_vectors)
# Check the trans_pgd_stub_vectors didn't overflow
.org . - (__trans_pgd_stub_vectors_end - trans_pgd_stub_vectors) + SZ_2K

27
arch/arm64/mm/trans_pgd.c
View file

@ -5,8 +5,8 @@
*
* This file derived from: arch/arm64/kernel/hibernate.c
*
* Copyright (c) 2020, Microsoft Corporation.
* Pavel Tatashin <pasha.tatashin@soleen.com>
* Copyright (c) 2021, Microsoft Corporation.
* Pasha Tatashin <pasha.tatashin@soleen.com>
*
*/
@ -322,3 +322,26 @@ int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
return 0;
}
/*
* Create a copy of the vector table so we can call HVC_SET_VECTORS or
* HVC_SOFT_RESTART from contexts where the table may be overwritten.
*/
int trans_pgd_copy_el2_vectors(struct trans_pgd_info *info,
phys_addr_t *el2_vectors)
{
void *hyp_stub = trans_alloc(info);
if (!hyp_stub)
return -ENOMEM;
*el2_vectors = virt_to_phys(hyp_stub);
memcpy(hyp_stub, &trans_pgd_stub_vectors, ARM64_VECTOR_TABLE_LEN);
caches_clean_inval_pou((unsigned long)hyp_stub,
(unsigned long)hyp_stub +
ARM64_VECTOR_TABLE_LEN);
dcache_clean_inval_poc((unsigned long)hyp_stub,
(unsigned long)hyp_stub +
ARM64_VECTOR_TABLE_LEN);
return 0;
}