bfa7965b33
Kfence only needs its pool to be mapped as page granularity, if it is inited early. Previous judgement was a bit over protected. From [1], Mark suggested to "just map the KFENCE region a page granularity". So I decouple it from judgement and do page granularity mapping for kfence pool only. Need to be noticed that late init of kfence pool still requires page granularity mapping. Page granularity mapping in theory cost more(2M per 1GB) memory on arm64 platform. Like what I've tested on QEMU(emulated 1GB RAM) with gki_defconfig, also turning off rodata protection: Before: [root@liebao ]# cat /proc/meminfo MemTotal: 999484 kB After: [root@liebao ]# cat /proc/meminfo MemTotal: 1001480 kB To implement this, also relocate the kfence pool allocation before the linear mapping setting up, arm64_kfence_alloc_pool is to allocate phys addr, __kfence_pool is to be set after linear mapping set up. LINK: [1] https://lore.kernel.org/linux-arm-kernel/Y+IsdrvDNILA59UN@FVFF77S0Q05N/ Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Marco Elver <elver@google.com> Link: https://lore.kernel.org/r/1679066974-690-1-git-send-email-quic_zhenhuah@quicinc.com Signed-off-by: Will Deacon <will@kernel.org>
33 lines
680 B
C
33 lines
680 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* arm64 KFENCE support.
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*
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* Copyright (C) 2020, Google LLC.
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*/
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#ifndef __ASM_KFENCE_H
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#define __ASM_KFENCE_H
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#include <asm/set_memory.h>
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static inline bool arch_kfence_init_pool(void) { return true; }
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static inline bool kfence_protect_page(unsigned long addr, bool protect)
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{
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set_memory_valid(addr, 1, !protect);
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return true;
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}
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#ifdef CONFIG_KFENCE
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extern bool kfence_early_init;
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static inline bool arm64_kfence_can_set_direct_map(void)
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{
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return !kfence_early_init;
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}
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#else /* CONFIG_KFENCE */
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static inline bool arm64_kfence_can_set_direct_map(void) { return false; }
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#endif /* CONFIG_KFENCE */
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#endif /* __ASM_KFENCE_H */
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