mirror of
https://github.com/torvalds/linux
synced 2024-10-08 04:12:40 +00:00
6e2edd6371
Commit18107f8a2d("arm64: Support execute-only permissions with Enhanced PAN") re-introduced execute-only permissions when EPAN is available. When EPAN is not available, arch_filter_pgprot() is supposed to change a PAGE_EXECONLY permission into PAGE_READONLY_EXEC. However, if BTI or MTE are present, such check does not detect the execute-only pgprot in the presence of PTE_GP (BTI) or MT_NORMAL_TAGGED (MTE), allowing the user to request PROT_EXEC with PROT_BTI or PROT_MTE. Remove the arch_filter_pgprot() function, change the default VM_EXEC permissions to PAGE_READONLY_EXEC and update the protection_map[] array at core_initcall() if EPAN is detected. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Fixes:18107f8a2d("arm64: Support execute-only permissions with Enhanced PAN") Cc: <stable@vger.kernel.org> # 5.13.x Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Based on arch/arm/mm/mmap.c
|
|
*
|
|
* Copyright (C) 2012 ARM Ltd.
|
|
*/
|
|
|
|
#include <linux/io.h>
|
|
#include <linux/memblock.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/types.h>
|
|
|
|
#include <asm/cpufeature.h>
|
|
#include <asm/page.h>
|
|
|
|
/*
|
|
* You really shouldn't be using read() or write() on /dev/mem. This might go
|
|
* away in the future.
|
|
*/
|
|
int valid_phys_addr_range(phys_addr_t addr, size_t size)
|
|
{
|
|
/*
|
|
* Check whether addr is covered by a memory region without the
|
|
* MEMBLOCK_NOMAP attribute, and whether that region covers the
|
|
* entire range. In theory, this could lead to false negatives
|
|
* if the range is covered by distinct but adjacent memory regions
|
|
* that only differ in other attributes. However, few of such
|
|
* attributes have been defined, and it is debatable whether it
|
|
* follows that /dev/mem read() calls should be able traverse
|
|
* such boundaries.
|
|
*/
|
|
return memblock_is_region_memory(addr, size) &&
|
|
memblock_is_map_memory(addr);
|
|
}
|
|
|
|
/*
|
|
* Do not allow /dev/mem mappings beyond the supported physical range.
|
|
*/
|
|
int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
|
|
{
|
|
return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
|
|
}
|
|
|
|
static int __init adjust_protection_map(void)
|
|
{
|
|
/*
|
|
* With Enhanced PAN we can honour the execute-only permissions as
|
|
* there is no PAN override with such mappings.
|
|
*/
|
|
if (cpus_have_const_cap(ARM64_HAS_EPAN)) {
|
|
protection_map[VM_EXEC] = PAGE_EXECONLY;
|
|
protection_map[VM_EXEC | VM_SHARED] = PAGE_EXECONLY;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
arch_initcall(adjust_protection_map);
|