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From: Steve Capper <steve.capper@arm.com>
To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu
Cc: catalin.marinas@arm.com, ard.biesheuvel@linaro.org
Subject: [PATCH 05/12] arm64: mm: Remove VMALLOC checks from update_mapping_prot(.)
Date: Mon,  4 Dec 2017 14:13:06 +0000	[thread overview]
Message-ID: <20171204141313.31604-6-steve.capper@arm.com> (raw)
In-Reply-To: <20171204141313.31604-1-steve.capper@arm.com>

update_mapping_prot assumes that it will be used on the VA for the
kernel .text section. (Via the check virt >= VMALLOC_START)

Recent kdump patches employ this function to modify the protection of
the direct linear mapping (which is strictly speaking outside of this
area), via mark_linear_text_alias_ro(.).

We "get away" with this as the direct linear mapping currently follows
the VA for the kernel text, so the check passes.

This patch removes the check in update_mapping_prot allowing us to move
the kernel VA layout without spuriously firing the warning.

Signed-off-by: Steve Capper <steve.capper@arm.com>
---
 arch/arm64/mm/mmu.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 58b1ed6fd7ec..c8f486384fe3 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -383,12 +383,6 @@ void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
 static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
 				phys_addr_t size, pgprot_t prot)
 {
-	if (virt < VMALLOC_START) {
-		pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n",
-			&phys, virt);
-		return;
-	}
-
 	__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
 			     NO_CONT_MAPPINGS);
 
-- 
2.11.0

  parent reply	other threads:[~2017-12-04 14:10 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-04 14:13 [PATCH 00/12] 52-bit kernel VAs for arm64 Steve Capper
2017-12-04 14:13 ` [PATCH 01/12] KVM: arm/arm64: vgic: Remove spurious call to kern_hyp_va Steve Capper
2017-12-04 14:30   ` Suzuki K Poulose
2017-12-12 11:53     ` Steve Capper
2017-12-04 14:13 ` [PATCH 02/12] arm64: KVM: Enforce injective kern_hyp_va mappings Steve Capper
2017-12-04 14:13 ` [PATCH 03/12] arm/arm64: KVM: Formalise end of direct linear map Steve Capper
2017-12-04 14:13 ` [PATCH 04/12] arm64: Initialise high_memory global variable earlier Steve Capper
2017-12-11 12:00   ` Catalin Marinas
2017-12-12 10:56     ` Steve Capper
2017-12-04 14:13 ` Steve Capper [this message]
2017-12-04 16:01   ` [PATCH 05/12] arm64: mm: Remove VMALLOC checks from update_mapping_prot(.) Ard Biesheuvel
2017-12-12 15:39     ` Steve Capper
2017-12-13 16:04       ` Catalin Marinas
2017-12-04 14:13 ` [PATCH 06/12] arm64: mm: Flip kernel VA space Steve Capper
2017-12-04 14:13 ` [PATCH 07/12] arm64: mm: Place kImage at bottom of " Steve Capper
2017-12-04 16:25   ` Ard Biesheuvel
2017-12-04 17:18     ` Steve Capper
2017-12-04 17:21       ` Steve Capper
2017-12-04 17:27       ` Ard Biesheuvel
2017-12-04 18:12         ` Steve Capper
2017-12-12 11:03           ` Steve Capper
2017-12-04 14:13 ` [PATCH 08/12] arm64: kasan: Switch to using KASAN_SHADOW_OFFSET Steve Capper
2017-12-04 14:13 ` [PATCH 09/12] arm64: dump: Make kernel page table dumper dynamic again Steve Capper
2017-12-04 14:13 ` [PATCH 10/12] arm64: mm: Make VA_BITS variable, introduce VA_BITS_MIN Steve Capper
2017-12-04 14:13 ` [PATCH 11/12] arm64: KVM: Add support for an alternative VA space Steve Capper
2017-12-04 14:13 ` [PATCH 12/12] arm64: mm: Add 48/52-bit kernel VA support Steve Capper

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