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authorPalmer Dabbelt <palmerdabbelt@google.com>2020-12-11 21:30:26 +0100
committerPalmer Dabbelt <palmerdabbelt@google.com>2020-12-11 21:30:26 +0100
commit7d95a88f9254b711a3a95106fc73f6a3a9866a40 (patch)
tree9c4551d7f2dce744bbefc359b941fd144f66333d
parentriscv: Fixed kernel test robot warning (diff)
parentarm64: Use the generic devmem_is_allowed() (diff)
downloadlinux-7d95a88f9254b711a3a95106fc73f6a3a9866a40.tar.xz
linux-7d95a88f9254b711a3a95106fc73f6a3a9866a40.zip
Add and use a generic version of devmem_is_allowed()
As part of adding STRICT_DEVMEM support to the RISC-V port, Zong provided an implementation of devmem_is_allowed() that's exactly the same as the version in a handful of other ports. Rather than duplicate code, I've put a generic version of this in lib/ and used it for the RISC-V port. * palmer/generic-devmem: arm64: Use the generic devmem_is_allowed() arm: Use the generic devmem_is_allowed() RISC-V: Use the new generic devmem_is_allowed() lib: Add a generic version of devmem_is_allowed()
-rw-r--r--arch/arm/Kconfig2
-rw-r--r--arch/arm/include/asm/io.h1
-rw-r--r--arch/arm/mm/mmap.c22
-rw-r--r--arch/arm64/Kconfig2
-rw-r--r--arch/arm64/include/asm/io.h2
-rw-r--r--arch/arm64/mm/mmap.c21
-rw-r--r--arch/riscv/Kconfig1
-rw-r--r--include/asm-generic/io.h4
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Kconfig.debug2
-rw-r--r--lib/Makefile2
-rw-r--r--lib/devmem_is_allowed.c27
12 files changed, 40 insertions, 49 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index fe2f17eb2b50..ae7c7364871b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -5,7 +5,6 @@ config ARM
select ARCH_32BIT_OFF_T
select ARCH_HAS_BINFMT_FLAT
select ARCH_HAS_DEBUG_VIRTUAL if MMU
- select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
@@ -56,6 +55,7 @@ config ARM
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
+ select GENERIC_LIB_DEVMEM_IS_ALLOWED
select GENERIC_PCI_IOMAP
select GENERIC_SCHED_CLOCK
select GENERIC_SMP_IDLE_THREAD
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index ab2b654084fa..fc748122f1e0 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -441,7 +441,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
-extern int devmem_is_allowed(unsigned long pfn);
#endif
/*
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index b8d912ac9e61..a0f8a0ca0788 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -165,25 +165,3 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
{
return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT));
}
-
-#ifdef CONFIG_STRICT_DEVMEM
-
-#include <linux/ioport.h>
-
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain
- * address is valid. The argument is a physical page number.
- * We mimic x86 here by disallowing access to system RAM as well as
- * device-exclusive MMIO regions. This effectively disable read()/write()
- * on /dev/mem.
- */
-int devmem_is_allowed(unsigned long pfn)
-{
- if (iomem_is_exclusive(pfn << PAGE_SHIFT))
- return 0;
- if (!page_is_ram(pfn))
- return 1;
- return 0;
-}
-
-#endif
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f858c352f72a..dd3c81d84e28 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -13,7 +13,6 @@ config ARM64
select ARCH_BINFMT_ELF_STATE
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEBUG_VM_PGTABLE
- select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_FAST_MULTIPLIER
@@ -112,6 +111,7 @@ config ARM64
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
+ select GENERIC_LIB_DEVMEM_IS_ALLOWED
select GENERIC_PCI_IOMAP
select GENERIC_PTDUMP
select GENERIC_SCHED_CLOCK
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index fd172c41df90..5ea8656a2030 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -201,6 +201,4 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
-extern int devmem_is_allowed(unsigned long pfn);
-
#endif /* __ASM_IO_H */
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index 3028bacbc4e9..07937b49cb88 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -47,24 +47,3 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
{
return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
}
-
-#ifdef CONFIG_STRICT_DEVMEM
-
-#include <linux/ioport.h>
-
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain address
- * is valid. The argument is a physical page number. We mimic x86 here by
- * disallowing access to system RAM as well as device-exclusive MMIO regions.
- * This effectively disable read()/write() on /dev/mem.
- */
-int devmem_is_allowed(unsigned long pfn)
-{
- if (iomem_is_exclusive(pfn << PAGE_SHIFT))
- return 0;
- if (!page_is_ram(pfn))
- return 1;
- return 0;
-}
-
-#endif
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d9da5d92e40d..2b41f6d8e458 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -44,6 +44,7 @@ config RISCV
select GENERIC_IOREMAP
select GENERIC_IRQ_MULTI_HANDLER
select GENERIC_IRQ_SHOW
+ select GENERIC_LIB_DEVMEM_IS_ALLOWED
select GENERIC_PCI_IOMAP
select GENERIC_PTDUMP if MMU
select GENERIC_SCHED_CLOCK
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 9ea83d80eb6f..c6af40ce03be 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1137,6 +1137,10 @@ static inline void memcpy_toio(volatile void __iomem *addr, const void *buffer,
}
#endif
+#ifndef CONFIG_GENERIC_DEVMEM_IS_ALLOWED
+extern int devmem_is_allowed(unsigned long pfn);
+#endif
+
#endif /* __KERNEL__ */
#endif /* __ASM_GENERIC_IO_H */
diff --git a/lib/Kconfig b/lib/Kconfig
index b46a9fd122c8..46806332a8cc 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -686,6 +686,9 @@ config GENERIC_LIB_CMPDI2
config GENERIC_LIB_UCMPDI2
bool
+config GENERIC_LIB_DEVMEM_IS_ALLOWED
+ bool
+
config PLDMFW
bool
default n
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d7a7bc3b6098..c63fc68f9bf2 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1645,7 +1645,7 @@ config ARCH_HAS_DEVMEM_IS_ALLOWED
config STRICT_DEVMEM
bool "Filter access to /dev/mem"
depends on MMU && DEVMEM
- depends on ARCH_HAS_DEVMEM_IS_ALLOWED
+ depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
default y if PPC || X86 || ARM64
help
If this option is disabled, you allow userspace (root) access to all
diff --git a/lib/Makefile b/lib/Makefile
index ce45af50983a..431d7d894bf7 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -352,3 +352,5 @@ obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o
obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
obj-$(CONFIG_BITS_TEST) += test_bits.o
+
+obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
diff --git a/lib/devmem_is_allowed.c b/lib/devmem_is_allowed.c
new file mode 100644
index 000000000000..c0d67c541849
--- /dev/null
+++ b/lib/devmem_is_allowed.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * A generic version of devmem_is_allowed.
+ *
+ * Based on arch/arm64/mm/mmap.c
+ *
+ * Copyright (C) 2020 Google, Inc.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/mm.h>
+#include <linux/ioport.h>
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number. We mimic x86 here by
+ * disallowing access to system RAM as well as device-exclusive MMIO regions.
+ * This effectively disable read()/write() on /dev/mem.
+ */
+int devmem_is_allowed(unsigned long pfn)
+{
+ if (iomem_is_exclusive(pfn << PAGE_SHIFT))
+ return 0;
+ if (!page_is_ram(pfn))
+ return 1;
+ return 0;
+}