diff options
| author | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2021-09-21 12:57:22 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2021-10-19 10:30:56 +0100 |
| commit | b8bc0e50a32a3c3b51605e41de41b4d7952e6aa4 (patch) | |
| tree | f30b5a2086dc1093e185f5877060ab8a1d18730d /arch | |
| parent | 48342ae751c797ac73ac9c894b3f312df18ffd21 (diff) | |
ARM: add __arm_iomem_set_ro() to write-protect ioremapped area
__arm_iomem_set_ro() marks an ioremapped area read-only. This is
intended for use with __arm_ioremap_exec() to allow the kernel to
write some code into e.g. SRAM and then write-protect it so the
kernel doesn't complain about W+X mappings.
Tested-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/io.h | 1 | ||||
| -rw-r--r-- | arch/arm/mm/ioremap.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index f74944c6fe8d..c576fa7d9bf8 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -138,6 +138,7 @@ extern void __iomem *__arm_ioremap_caller(phys_addr_t, size_t, unsigned int, void *); extern void __iomem *__arm_ioremap_pfn(unsigned long, unsigned long, size_t, unsigned int); extern void __iomem *__arm_ioremap_exec(phys_addr_t, size_t, bool cached); +void __arm_iomem_set_ro(void __iomem *ptr, size_t size); extern void __iounmap(volatile void __iomem *addr); extern void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t, diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index 80fb5a4a5c05..6e830b9418c9 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -36,6 +36,7 @@ #include <asm/mmu_context.h> #include <asm/pgalloc.h> #include <asm/tlbflush.h> +#include <asm/set_memory.h> #include <asm/system_info.h> #include <asm/mach/map.h> @@ -401,6 +402,11 @@ __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached) __builtin_return_address(0)); } +void __arm_iomem_set_ro(void __iomem *ptr, size_t size) +{ + set_memory_ro((unsigned long)ptr, PAGE_ALIGN(size) / PAGE_SIZE); +} + void *arch_memremap_wb(phys_addr_t phys_addr, size_t size) { return (__force void *)arch_ioremap_caller(phys_addr, size, |