* [PATCH 0/2] Add STRICT_DEVMEM support on RISC-V @ 2020-06-16 7:45 Zong Li 2020-06-16 7:45 ` [PATCH 1/2] riscv: Register System RAM as iomem resources Zong Li 2020-06-16 7:45 ` [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM Zong Li 0 siblings, 2 replies; 13+ messages in thread From: Zong Li @ 2020-06-16 7:45 UTC (permalink / raw) To: paul.walmsley, palmer, linux-riscv, linux-kernel; +Cc: Zong Li This patchset include two parts, the first one is that register System RAM as iomem resources, it is needed for page_is_ram API which checks the specified address whether registered as System RAM in iomem_resource list. The second patch is that add devmem_is_allowed to support STRICT_DEVMEM, and it would invoke page_is_ram to check the addresses. Zong Li (2): riscv: Register System RAM as iomem resources riscv: Support CONFIG_STRICT_DEVMEM arch/riscv/Kconfig | 1 + arch/riscv/include/asm/io.h | 2 ++ arch/riscv/mm/init.c | 41 +++++++++++++++++++++++++++++++++++++ 3 files changed, 44 insertions(+) -- 2.27.0 ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 1/2] riscv: Register System RAM as iomem resources 2020-06-16 7:45 [PATCH 0/2] Add STRICT_DEVMEM support on RISC-V Zong Li @ 2020-06-16 7:45 ` Zong Li 2020-06-16 11:51 ` Nick Kossifidis 2020-07-09 18:27 ` Palmer Dabbelt 2020-06-16 7:45 ` [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM Zong Li 1 sibling, 2 replies; 13+ messages in thread From: Zong Li @ 2020-06-16 7:45 UTC (permalink / raw) To: paul.walmsley, palmer, linux-riscv, linux-kernel; +Cc: Zong Li Add System RAM to /proc/iomem, various tools expect it such as kdump. It is also needed for page_is_ram API which checks the specified address whether registered as System RAM in iomem_resource list. Signed-off-by: Zong Li <zong.li@sifive.com> --- arch/riscv/mm/init.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index f4adb3684f3d..bbe816e03b2f 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -517,6 +517,27 @@ void mark_rodata_ro(void) } #endif +void __init resource_init(void) +{ + struct memblock_region *region; + + for_each_memblock(memory, region) { + struct resource *res; + + res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); + if (!res) + panic("%s: Failed to allocate %zu bytes\n", __func__, + sizeof(struct resource)); + + res->name = "System RAM"; + res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); + res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1; + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + + request_resource(&iomem_resource, res); + } +} + void __init paging_init(void) { setup_vm_final(); @@ -524,6 +545,7 @@ void __init paging_init(void) sparse_init(); setup_zero_page(); zone_sizes_init(); + resource_init(); } #ifdef CONFIG_SPARSEMEM_VMEMMAP -- 2.27.0 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH 1/2] riscv: Register System RAM as iomem resources 2020-06-16 7:45 ` [PATCH 1/2] riscv: Register System RAM as iomem resources Zong Li @ 2020-06-16 11:51 ` Nick Kossifidis 2020-06-17 1:23 ` Zong Li 2020-07-09 18:27 ` Palmer Dabbelt 1 sibling, 1 reply; 13+ messages in thread From: Nick Kossifidis @ 2020-06-16 11:51 UTC (permalink / raw) To: Zong Li; +Cc: paul.walmsley, palmer, linux-riscv, linux-kernel Στις 2020-06-16 10:45, Zong Li έγραψε: > Add System RAM to /proc/iomem, various tools expect it such as kdump. > It is also needed for page_is_ram API which checks the specified > address > whether registered as System RAM in iomem_resource list. > > Signed-off-by: Zong Li <zong.li@sifive.com> > --- > arch/riscv/mm/init.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index f4adb3684f3d..bbe816e03b2f 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -517,6 +517,27 @@ void mark_rodata_ro(void) > } > #endif > > +void __init resource_init(void) > +{ > + struct memblock_region *region; > + > + for_each_memblock(memory, region) { > + struct resource *res; > + > + res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); > + if (!res) > + panic("%s: Failed to allocate %zu bytes\n", __func__, > + sizeof(struct resource)); > + > + res->name = "System RAM"; > + res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); > + res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - > 1; > + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > + > + request_resource(&iomem_resource, res); > + } > +} > + > void __init paging_init(void) > { > setup_vm_final(); > @@ -524,6 +545,7 @@ void __init paging_init(void) > sparse_init(); > setup_zero_page(); > zone_sizes_init(); > + resource_init(); > } > > #ifdef CONFIG_SPARSEMEM_VMEMMAP I already have a patch for registering System RAM as an iomem resource on my kexec/kdump series. Since I don't care about System RAM regions being accurately exposed to userspace (I parse the current device tree instead) I just use memblock_start_of_DRAM/end_of_DRAM. This approach from arm64 codebase is better since it also handles the case of sparse memory regions but in order to be useful for kdump we need to add the various segments of the kernel image as child nodes to their respective region for kexec-tools. I'll re-spin my patchset anyway so I'll extend it to better handle System RAM regions. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 1/2] riscv: Register System RAM as iomem resources 2020-06-16 11:51 ` Nick Kossifidis @ 2020-06-17 1:23 ` Zong Li 0 siblings, 0 replies; 13+ messages in thread From: Zong Li @ 2020-06-17 1:23 UTC (permalink / raw) To: Nick Kossifidis Cc: Paul Walmsley, Palmer Dabbelt, linux-riscv, linux-kernel@vger.kernel.org List On Tue, Jun 16, 2020 at 7:52 PM Nick Kossifidis <mick@ics.forth.gr> wrote: > > Στις 2020-06-16 10:45, Zong Li έγραψε: > > Add System RAM to /proc/iomem, various tools expect it such as kdump. > > It is also needed for page_is_ram API which checks the specified > > address > > whether registered as System RAM in iomem_resource list. > > > > Signed-off-by: Zong Li <zong.li@sifive.com> > > --- > > arch/riscv/mm/init.c | 22 ++++++++++++++++++++++ > > 1 file changed, 22 insertions(+) > > > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > index f4adb3684f3d..bbe816e03b2f 100644 > > --- a/arch/riscv/mm/init.c > > +++ b/arch/riscv/mm/init.c > > @@ -517,6 +517,27 @@ void mark_rodata_ro(void) > > } > > #endif > > > > +void __init resource_init(void) > > +{ > > + struct memblock_region *region; > > + > > + for_each_memblock(memory, region) { > > + struct resource *res; > > + > > + res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); > > + if (!res) > > + panic("%s: Failed to allocate %zu bytes\n", __func__, > > + sizeof(struct resource)); > > + > > + res->name = "System RAM"; > > + res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); > > + res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - > > 1; > > + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > > + > > + request_resource(&iomem_resource, res); > > + } > > +} > > + > > void __init paging_init(void) > > { > > setup_vm_final(); > > @@ -524,6 +545,7 @@ void __init paging_init(void) > > sparse_init(); > > setup_zero_page(); > > zone_sizes_init(); > > + resource_init(); > > } > > > > #ifdef CONFIG_SPARSEMEM_VMEMMAP > > > I already have a patch for registering System RAM as an iomem resource > on my kexec/kdump series. Since I don't care about System RAM regions > being accurately exposed to userspace (I parse the current device tree > instead) I just use memblock_start_of_DRAM/end_of_DRAM. This approach > from arm64 codebase is better since it also handles the case of sparse > memory regions but in order to be useful for kdump we need to add the > various segments of the kernel image as child nodes to their respective > region for kexec-tools. I'll re-spin my patchset anyway so I'll extend > it to better handle System RAM regions. OK, great, I would remove this patch here and only reserve the second patch in the next version. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 1/2] riscv: Register System RAM as iomem resources 2020-06-16 7:45 ` [PATCH 1/2] riscv: Register System RAM as iomem resources Zong Li 2020-06-16 11:51 ` Nick Kossifidis @ 2020-07-09 18:27 ` Palmer Dabbelt 2020-07-10 2:05 ` Nick Kossifidis 1 sibling, 1 reply; 13+ messages in thread From: Palmer Dabbelt @ 2020-07-09 18:27 UTC (permalink / raw) To: zong.li; +Cc: Paul Walmsley, linux-riscv, linux-kernel, zong.li On Tue, 16 Jun 2020 00:45:46 PDT (-0700), zong.li@sifive.com wrote: > Add System RAM to /proc/iomem, various tools expect it such as kdump. > It is also needed for page_is_ram API which checks the specified address > whether registered as System RAM in iomem_resource list. > > Signed-off-by: Zong Li <zong.li@sifive.com> > --- > arch/riscv/mm/init.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index f4adb3684f3d..bbe816e03b2f 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -517,6 +517,27 @@ void mark_rodata_ro(void) > } > #endif > > +void __init resource_init(void) > +{ > + struct memblock_region *region; > + > + for_each_memblock(memory, region) { > + struct resource *res; > + > + res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); > + if (!res) > + panic("%s: Failed to allocate %zu bytes\n", __func__, > + sizeof(struct resource)); > + > + res->name = "System RAM"; > + res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); > + res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1; > + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; Looks like everyone else is checking MEMBLOCK_NOMAP before registering memory regions. I've added that and put this on for-next. Thanks! commit 11dc632bf515874c84887727614e8044452f1f28 gpg: Signature made Thu 09 Jul 2020 11:24:08 AM PDT gpg: using RSA key 2B3C3747446843B24A943A7A2E1319F35FBB1889 gpg: issuer "palmer@dabbelt.com" gpg: Good signature from "Palmer Dabbelt <palmer@dabbelt.com>" [ultimate] gpg: aka "Palmer Dabbelt <palmerdabbelt@google.com>" [ultimate] Author: Zong Li <zong.li@sifive.com> Date: Tue Jun 16 15:45:46 2020 +0800 riscv: Register System RAM as iomem resources Add System RAM to /proc/iomem, various tools expect it such as kdump. It is also needed for page_is_ram API which checks the specified address whether registered as System RAM in iomem_resource list. Signed-off-by: Zong Li <zong.li@sifive.com> [Palmer: check MEMBLOCK_NOMAP] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index f4adb3684f3d..8b78fd23713e 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -517,6 +517,32 @@ void mark_rodata_ro(void) } #endif +void __init resource_init(void) +{ + struct memblock_region *region; + + for_each_memblock(memory, region) { + struct resource *res; + + res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); + if (!res) + panic("%s: Failed to allocate %zu bytes\n", __func__, + sizeof(struct resource)); + + if (memblock_is_nomap(region) { + res->name = "reserved"; + res->flags = IORESOURCE_MEM; + } else { + res->name = "System RAM"; + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + } + res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); + res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1; + + request_resource(&iomem_resource, res); + } +} + void __init paging_init(void) { setup_vm_final(); @@ -524,6 +550,7 @@ void __init paging_init(void) sparse_init(); setup_zero_page(); zone_sizes_init(); + resource_init(); } #ifdef CONFIG_SPARSEMEM_VMEMMAP > + > + request_resource(&iomem_resource, res); > + } > +} > + > void __init paging_init(void) > { > setup_vm_final(); > @@ -524,6 +545,7 @@ void __init paging_init(void) > sparse_init(); > setup_zero_page(); > zone_sizes_init(); > + resource_init(); > } > > #ifdef CONFIG_SPARSEMEM_VMEMMAP ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH 1/2] riscv: Register System RAM as iomem resources 2020-07-09 18:27 ` Palmer Dabbelt @ 2020-07-10 2:05 ` Nick Kossifidis 0 siblings, 0 replies; 13+ messages in thread From: Nick Kossifidis @ 2020-07-10 2:05 UTC (permalink / raw) To: Palmer Dabbelt; +Cc: zong.li, linux-riscv, linux-kernel, Paul Walmsley Στις 2020-07-09 21:27, Palmer Dabbelt έγραψε: > On Tue, 16 Jun 2020 00:45:46 PDT (-0700), zong.li@sifive.com wrote: >> Add System RAM to /proc/iomem, various tools expect it such as kdump. >> It is also needed for page_is_ram API which checks the specified >> address >> whether registered as System RAM in iomem_resource list. >> >> Signed-off-by: Zong Li <zong.li@sifive.com> >> --- >> arch/riscv/mm/init.c | 22 ++++++++++++++++++++++ >> 1 file changed, 22 insertions(+) >> >> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >> index f4adb3684f3d..bbe816e03b2f 100644 >> --- a/arch/riscv/mm/init.c >> +++ b/arch/riscv/mm/init.c >> @@ -517,6 +517,27 @@ void mark_rodata_ro(void) >> } >> #endif >> >> +void __init resource_init(void) >> +{ >> + struct memblock_region *region; >> + >> + for_each_memblock(memory, region) { >> + struct resource *res; >> + >> + res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); >> + if (!res) >> + panic("%s: Failed to allocate %zu bytes\n", __func__, >> + sizeof(struct resource)); >> + >> + res->name = "System RAM"; >> + res->start = >> __pfn_to_phys(memblock_region_memory_base_pfn(region)); >> + res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - >> 1; >> + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > > Looks like everyone else is checking MEMBLOCK_NOMAP before registering > memory > regions. I've added that and put this on for-next. Thanks! > > commit 11dc632bf515874c84887727614e8044452f1f28 > gpg: Signature made Thu 09 Jul 2020 11:24:08 AM PDT > gpg: using RSA key > 2B3C3747446843B24A943A7A2E1319F35FBB1889 > gpg: issuer "palmer@dabbelt.com" > gpg: Good signature from "Palmer Dabbelt <palmer@dabbelt.com>" > [ultimate] > gpg: aka "Palmer Dabbelt <palmerdabbelt@google.com>" > [ultimate] > Author: Zong Li <zong.li@sifive.com> > Date: Tue Jun 16 15:45:46 2020 +0800 > > riscv: Register System RAM as iomem resources > Add System RAM to /proc/iomem, various tools expect it such as > kdump. > It is also needed for page_is_ram API which checks the specified > address > whether registered as System RAM in iomem_resource list. > Signed-off-by: Zong Li <zong.li@sifive.com> > [Palmer: check MEMBLOCK_NOMAP] > Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index f4adb3684f3d..8b78fd23713e 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -517,6 +517,32 @@ void mark_rodata_ro(void) > } > #endif > > +void __init resource_init(void) > +{ > + struct memblock_region *region; > + > + for_each_memblock(memory, region) { > + struct resource *res; > + > + res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); > + if (!res) > + panic("%s: Failed to allocate %zu bytes\n", __func__, > + sizeof(struct resource)); > + > + if (memblock_is_nomap(region) { > + res->name = "reserved"; > + res->flags = IORESOURCE_MEM; > + } else { > + res->name = "System RAM"; > + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > + } > + res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); > + res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - > 1; > + > + request_resource(&iomem_resource, res); > + } > +} > + > void __init paging_init(void) > { > setup_vm_final(); > @@ -524,6 +550,7 @@ void __init paging_init(void) > sparse_init(); > setup_zero_page(); > zone_sizes_init(); > + resource_init(); > } > > #ifdef CONFIG_SPARSEMEM_VMEMMAP > > >> + >> + request_resource(&iomem_resource, res); >> + } >> +} >> + >> void __init paging_init(void) >> { >> setup_vm_final(); >> @@ -524,6 +545,7 @@ void __init paging_init(void) >> sparse_init(); >> setup_zero_page(); >> zone_sizes_init(); >> + resource_init(); >> } >> >> #ifdef CONFIG_SPARSEMEM_VMEMMAP > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv Zong Li sent a newer version of this series without this patch, since I'm handling this on the kexec/kdump series as well where other sections needed for kdump are also registered. ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM 2020-06-16 7:45 [PATCH 0/2] Add STRICT_DEVMEM support on RISC-V Zong Li 2020-06-16 7:45 ` [PATCH 1/2] riscv: Register System RAM as iomem resources Zong Li @ 2020-06-16 7:45 ` Zong Li 2020-06-16 12:27 ` Nick Kossifidis 2020-07-09 20:08 ` Palmer Dabbelt 1 sibling, 2 replies; 13+ messages in thread From: Zong Li @ 2020-06-16 7:45 UTC (permalink / raw) To: paul.walmsley, palmer, linux-riscv, linux-kernel; +Cc: Zong Li Implement the 'devmem_is_allowed()' interface for RISC-V, like some of other architectures have done. It will be called from range_is_allowed() when userpsace attempts to access /dev/mem. Access to exclusive IOMEM and kernel RAM is denied unless CONFIG_STRICT_DEVMEM is set to 'n'. Test it by devmem, the result as follows: - CONFIG_STRICT_DEVMEM=y $ devmem 0x10010000 0x00000000 $ devmem 0x80200000 0x0000106F - CONFIG_STRICT_DEVMEM is not set $ devmem 0x10010000 devmem: mmap: Operation not permitted $ devmem 0x80200000 devmem: mmap: Operation not permitted Signed-off-by: Zong Li <zong.li@sifive.com> --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/io.h | 2 ++ arch/riscv/mm/init.c | 19 +++++++++++++++++++ 3 files changed, 22 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 128192e14ff2..ffd7841ede4c 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -16,6 +16,7 @@ config RISCV select ARCH_HAS_BINFMT_FLAT select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEBUG_WX + select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_GIGANTIC_PAGE select ARCH_HAS_MMIOWB diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h index 3835c3295dc5..04ac65ab93ce 100644 --- a/arch/riscv/include/asm/io.h +++ b/arch/riscv/include/asm/io.h @@ -147,4 +147,6 @@ __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw()) #include <asm-generic/io.h> +extern int devmem_is_allowed(unsigned long pfn); + #endif /* _ASM_RISCV_IO_H */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index bbe816e03b2f..5e7e61519acc 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -517,6 +517,25 @@ void mark_rodata_ro(void) } #endif +#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. + * + * Disallow 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 + void __init resource_init(void) { struct memblock_region *region; -- 2.27.0 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM 2020-06-16 7:45 ` [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM Zong Li @ 2020-06-16 12:27 ` Nick Kossifidis 2020-06-17 1:56 ` Zong Li 2020-07-09 20:08 ` Palmer Dabbelt 1 sibling, 1 reply; 13+ messages in thread From: Nick Kossifidis @ 2020-06-16 12:27 UTC (permalink / raw) To: Zong Li; +Cc: paul.walmsley, palmer, linux-riscv, linux-kernel Στις 2020-06-16 10:45, Zong Li έγραψε: > Implement the 'devmem_is_allowed()' interface for RISC-V, like some of > other architectures have done. It will be called from > range_is_allowed() > when userpsace attempts to access /dev/mem. > > Access to exclusive IOMEM and kernel RAM is denied unless > CONFIG_STRICT_DEVMEM is set to 'n'. > > Test it by devmem, the result as follows: > > - CONFIG_STRICT_DEVMEM=y > $ devmem 0x10010000 > 0x00000000 > $ devmem 0x80200000 > 0x0000106F > > - CONFIG_STRICT_DEVMEM is not set > $ devmem 0x10010000 > devmem: mmap: Operation not permitted > $ devmem 0x80200000 > devmem: mmap: Operation not permitted > > Signed-off-by: Zong Li <zong.li@sifive.com> > --- > arch/riscv/Kconfig | 1 + > arch/riscv/include/asm/io.h | 2 ++ > arch/riscv/mm/init.c | 19 +++++++++++++++++++ > 3 files changed, 22 insertions(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 128192e14ff2..ffd7841ede4c 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -16,6 +16,7 @@ config RISCV > select ARCH_HAS_BINFMT_FLAT > select ARCH_HAS_DEBUG_VIRTUAL if MMU > select ARCH_HAS_DEBUG_WX > + select ARCH_HAS_DEVMEM_IS_ALLOWED > select ARCH_HAS_GCOV_PROFILE_ALL > select ARCH_HAS_GIGANTIC_PAGE > select ARCH_HAS_MMIOWB > diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h > index 3835c3295dc5..04ac65ab93ce 100644 > --- a/arch/riscv/include/asm/io.h > +++ b/arch/riscv/include/asm/io.h > @@ -147,4 +147,6 @@ __io_writes_outs(outs, u64, q, __io_pbr(), > __io_paw()) > > #include <asm-generic/io.h> > > +extern int devmem_is_allowed(unsigned long pfn); > + > #endif /* _ASM_RISCV_IO_H */ > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index bbe816e03b2f..5e7e61519acc 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -517,6 +517,25 @@ void mark_rodata_ro(void) > } > #endif > > +#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. > + * > + * Disallow 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 > + > void __init resource_init(void) > { > struct memblock_region *region; This shouldn't be part of /mm/init.c, it has nothing to do with memory initialization, I suggest we move it to another file like mmap.c on arm/arm64. Also before using iomem_is_exclusive we should probably also mark any reserved regions with the no-map attribute as busy|exclusive, reserved-memory regions are not necessarily part of the main memory so the page_is_ram check may pass and iomem_is_exclusive won't do any good. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM 2020-06-16 12:27 ` Nick Kossifidis @ 2020-06-17 1:56 ` Zong Li 2020-06-17 5:28 ` Nick Kossifidis 0 siblings, 1 reply; 13+ messages in thread From: Zong Li @ 2020-06-17 1:56 UTC (permalink / raw) To: Nick Kossifidis Cc: Paul Walmsley, Palmer Dabbelt, linux-riscv, linux-kernel@vger.kernel.org List On Tue, Jun 16, 2020 at 8:27 PM Nick Kossifidis <mick@ics.forth.gr> wrote: > > Στις 2020-06-16 10:45, Zong Li έγραψε: > > Implement the 'devmem_is_allowed()' interface for RISC-V, like some of > > other architectures have done. It will be called from > > range_is_allowed() > > when userpsace attempts to access /dev/mem. > > > > Access to exclusive IOMEM and kernel RAM is denied unless > > CONFIG_STRICT_DEVMEM is set to 'n'. > > > > Test it by devmem, the result as follows: > > > > - CONFIG_STRICT_DEVMEM=y > > $ devmem 0x10010000 > > 0x00000000 > > $ devmem 0x80200000 > > 0x0000106F > > > > - CONFIG_STRICT_DEVMEM is not set > > $ devmem 0x10010000 > > devmem: mmap: Operation not permitted > > $ devmem 0x80200000 > > devmem: mmap: Operation not permitted > > > > Signed-off-by: Zong Li <zong.li@sifive.com> > > --- > > arch/riscv/Kconfig | 1 + > > arch/riscv/include/asm/io.h | 2 ++ > > arch/riscv/mm/init.c | 19 +++++++++++++++++++ > > 3 files changed, 22 insertions(+) > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 128192e14ff2..ffd7841ede4c 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -16,6 +16,7 @@ config RISCV > > select ARCH_HAS_BINFMT_FLAT > > select ARCH_HAS_DEBUG_VIRTUAL if MMU > > select ARCH_HAS_DEBUG_WX > > + select ARCH_HAS_DEVMEM_IS_ALLOWED > > select ARCH_HAS_GCOV_PROFILE_ALL > > select ARCH_HAS_GIGANTIC_PAGE > > select ARCH_HAS_MMIOWB > > diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h > > index 3835c3295dc5..04ac65ab93ce 100644 > > --- a/arch/riscv/include/asm/io.h > > +++ b/arch/riscv/include/asm/io.h > > @@ -147,4 +147,6 @@ __io_writes_outs(outs, u64, q, __io_pbr(), > > __io_paw()) > > > > #include <asm-generic/io.h> > > > > +extern int devmem_is_allowed(unsigned long pfn); > > + > > #endif /* _ASM_RISCV_IO_H */ > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > index bbe816e03b2f..5e7e61519acc 100644 > > --- a/arch/riscv/mm/init.c > > +++ b/arch/riscv/mm/init.c > > @@ -517,6 +517,25 @@ void mark_rodata_ro(void) > > } > > #endif > > > > +#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. > > + * > > + * Disallow 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 > > + > > void __init resource_init(void) > > { > > struct memblock_region *region; > > This shouldn't be part of /mm/init.c, it has nothing to do with memory > initialization, I suggest we move it to another file like mmap.c on Let me move it, thanks. > arm/arm64. Also before using iomem_is_exclusive we should probably also > mark any reserved regions with the no-map attribute as busy|exclusive, > reserved-memory regions are not necessarily part of the main memory so > the page_is_ram check may pass and iomem_is_exclusive won't do any good. What do you think if we mark the reserved region in kdump_resource_init, and change the kdump_resource_init to a more generic name for initializing resources? ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM 2020-06-17 1:56 ` Zong Li @ 2020-06-17 5:28 ` Nick Kossifidis 2020-06-17 6:32 ` Zong Li 0 siblings, 1 reply; 13+ messages in thread From: Nick Kossifidis @ 2020-06-17 5:28 UTC (permalink / raw) To: Zong Li Cc: Nick Kossifidis, Paul Walmsley, Palmer Dabbelt, linux-riscv, linux-kernel@vger.kernel.org List Στις 2020-06-17 04:56, Zong Li έγραψε: > On Tue, Jun 16, 2020 at 8:27 PM Nick Kossifidis <mick@ics.forth.gr> > wrote: >> >> Στις 2020-06-16 10:45, Zong Li έγραψε: >> > Implement the 'devmem_is_allowed()' interface for RISC-V, like some of >> > other architectures have done. It will be called from >> > range_is_allowed() >> > when userpsace attempts to access /dev/mem. >> > >> > Access to exclusive IOMEM and kernel RAM is denied unless >> > CONFIG_STRICT_DEVMEM is set to 'n'. >> > >> > Test it by devmem, the result as follows: >> > >> > - CONFIG_STRICT_DEVMEM=y >> > $ devmem 0x10010000 >> > 0x00000000 >> > $ devmem 0x80200000 >> > 0x0000106F >> > >> > - CONFIG_STRICT_DEVMEM is not set >> > $ devmem 0x10010000 >> > devmem: mmap: Operation not permitted >> > $ devmem 0x80200000 >> > devmem: mmap: Operation not permitted >> > >> > Signed-off-by: Zong Li <zong.li@sifive.com> >> > --- >> > arch/riscv/Kconfig | 1 + >> > arch/riscv/include/asm/io.h | 2 ++ >> > arch/riscv/mm/init.c | 19 +++++++++++++++++++ >> > 3 files changed, 22 insertions(+) >> > >> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> > index 128192e14ff2..ffd7841ede4c 100644 >> > --- a/arch/riscv/Kconfig >> > +++ b/arch/riscv/Kconfig >> > @@ -16,6 +16,7 @@ config RISCV >> > select ARCH_HAS_BINFMT_FLAT >> > select ARCH_HAS_DEBUG_VIRTUAL if MMU >> > select ARCH_HAS_DEBUG_WX >> > + select ARCH_HAS_DEVMEM_IS_ALLOWED >> > select ARCH_HAS_GCOV_PROFILE_ALL >> > select ARCH_HAS_GIGANTIC_PAGE >> > select ARCH_HAS_MMIOWB >> > diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h >> > index 3835c3295dc5..04ac65ab93ce 100644 >> > --- a/arch/riscv/include/asm/io.h >> > +++ b/arch/riscv/include/asm/io.h >> > @@ -147,4 +147,6 @@ __io_writes_outs(outs, u64, q, __io_pbr(), >> > __io_paw()) >> > >> > #include <asm-generic/io.h> >> > >> > +extern int devmem_is_allowed(unsigned long pfn); >> > + >> > #endif /* _ASM_RISCV_IO_H */ >> > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >> > index bbe816e03b2f..5e7e61519acc 100644 >> > --- a/arch/riscv/mm/init.c >> > +++ b/arch/riscv/mm/init.c >> > @@ -517,6 +517,25 @@ void mark_rodata_ro(void) >> > } >> > #endif >> > >> > +#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. >> > + * >> > + * Disallow 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 >> > + >> > void __init resource_init(void) >> > { >> > struct memblock_region *region; >> >> This shouldn't be part of /mm/init.c, it has nothing to do with memory >> initialization, I suggest we move it to another file like mmap.c on > > Let me move it, thanks. > >> arm/arm64. Also before using iomem_is_exclusive we should probably >> also >> mark any reserved regions with the no-map attribute as busy|exclusive, >> reserved-memory regions are not necessarily part of the main memory so >> the page_is_ram check may pass and iomem_is_exclusive won't do any >> good. > > What do you think if we mark the reserved region in > kdump_resource_init, and change the kdump_resource_init to a more > generic name for initializing resources? Sounds good to me, I'll work on this within the week. Do you agree with marking the no-map reserved-memory regions as exclusive ? ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM 2020-06-17 5:28 ` Nick Kossifidis @ 2020-06-17 6:32 ` Zong Li 0 siblings, 0 replies; 13+ messages in thread From: Zong Li @ 2020-06-17 6:32 UTC (permalink / raw) To: Nick Kossifidis Cc: Paul Walmsley, Palmer Dabbelt, linux-riscv, linux-kernel@vger.kernel.org List On Wed, Jun 17, 2020 at 1:28 PM Nick Kossifidis <mick@ics.forth.gr> wrote: > > Στις 2020-06-17 04:56, Zong Li έγραψε: > > On Tue, Jun 16, 2020 at 8:27 PM Nick Kossifidis <mick@ics.forth.gr> > > wrote: > >> > >> Στις 2020-06-16 10:45, Zong Li έγραψε: > >> > Implement the 'devmem_is_allowed()' interface for RISC-V, like some of > >> > other architectures have done. It will be called from > >> > range_is_allowed() > >> > when userpsace attempts to access /dev/mem. > >> > > >> > Access to exclusive IOMEM and kernel RAM is denied unless > >> > CONFIG_STRICT_DEVMEM is set to 'n'. > >> > > >> > Test it by devmem, the result as follows: > >> > > >> > - CONFIG_STRICT_DEVMEM=y > >> > $ devmem 0x10010000 > >> > 0x00000000 > >> > $ devmem 0x80200000 > >> > 0x0000106F > >> > > >> > - CONFIG_STRICT_DEVMEM is not set > >> > $ devmem 0x10010000 > >> > devmem: mmap: Operation not permitted > >> > $ devmem 0x80200000 > >> > devmem: mmap: Operation not permitted > >> > > >> > Signed-off-by: Zong Li <zong.li@sifive.com> > >> > --- > >> > arch/riscv/Kconfig | 1 + > >> > arch/riscv/include/asm/io.h | 2 ++ > >> > arch/riscv/mm/init.c | 19 +++++++++++++++++++ > >> > 3 files changed, 22 insertions(+) > >> > > >> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > >> > index 128192e14ff2..ffd7841ede4c 100644 > >> > --- a/arch/riscv/Kconfig > >> > +++ b/arch/riscv/Kconfig > >> > @@ -16,6 +16,7 @@ config RISCV > >> > select ARCH_HAS_BINFMT_FLAT > >> > select ARCH_HAS_DEBUG_VIRTUAL if MMU > >> > select ARCH_HAS_DEBUG_WX > >> > + select ARCH_HAS_DEVMEM_IS_ALLOWED > >> > select ARCH_HAS_GCOV_PROFILE_ALL > >> > select ARCH_HAS_GIGANTIC_PAGE > >> > select ARCH_HAS_MMIOWB > >> > diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h > >> > index 3835c3295dc5..04ac65ab93ce 100644 > >> > --- a/arch/riscv/include/asm/io.h > >> > +++ b/arch/riscv/include/asm/io.h > >> > @@ -147,4 +147,6 @@ __io_writes_outs(outs, u64, q, __io_pbr(), > >> > __io_paw()) > >> > > >> > #include <asm-generic/io.h> > >> > > >> > +extern int devmem_is_allowed(unsigned long pfn); > >> > + > >> > #endif /* _ASM_RISCV_IO_H */ > >> > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > >> > index bbe816e03b2f..5e7e61519acc 100644 > >> > --- a/arch/riscv/mm/init.c > >> > +++ b/arch/riscv/mm/init.c > >> > @@ -517,6 +517,25 @@ void mark_rodata_ro(void) > >> > } > >> > #endif > >> > > >> > +#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. > >> > + * > >> > + * Disallow 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 > >> > + > >> > void __init resource_init(void) > >> > { > >> > struct memblock_region *region; > >> > >> This shouldn't be part of /mm/init.c, it has nothing to do with memory > >> initialization, I suggest we move it to another file like mmap.c on > > > > Let me move it, thanks. > > > >> arm/arm64. Also before using iomem_is_exclusive we should probably > >> also > >> mark any reserved regions with the no-map attribute as busy|exclusive, > >> reserved-memory regions are not necessarily part of the main memory so > >> the page_is_ram check may pass and iomem_is_exclusive won't do any > >> good. > > > > What do you think if we mark the reserved region in > > kdump_resource_init, and change the kdump_resource_init to a more > > generic name for initializing resources? > > Sounds good to me, I'll work on this within the week. Do you agree with > marking the no-map reserved-memory regions as exclusive ? It's OK to me, It seems to me that exclusive is more suitable than busy when initialization. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM 2020-06-16 7:45 ` [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM Zong Li 2020-06-16 12:27 ` Nick Kossifidis @ 2020-07-09 20:08 ` Palmer Dabbelt 2020-07-10 2:43 ` Zong Li 1 sibling, 1 reply; 13+ messages in thread From: Palmer Dabbelt @ 2020-07-09 20:08 UTC (permalink / raw) To: zong.li; +Cc: Paul Walmsley, linux-riscv, linux-kernel, zong.li On Tue, 16 Jun 2020 00:45:47 PDT (-0700), zong.li@sifive.com wrote: > Implement the 'devmem_is_allowed()' interface for RISC-V, like some of > other architectures have done. It will be called from range_is_allowed() > when userpsace attempts to access /dev/mem. In fact, it's exactly the same (down to a few words of the comment) to the others that I checked. I'm going to put a generic version in lib/ instead, I've sent out the patches. > Access to exclusive IOMEM and kernel RAM is denied unless > CONFIG_STRICT_DEVMEM is set to 'n'. > > Test it by devmem, the result as follows: > > - CONFIG_STRICT_DEVMEM=y > $ devmem 0x10010000 > 0x00000000 > $ devmem 0x80200000 > 0x0000106F > > - CONFIG_STRICT_DEVMEM is not set > $ devmem 0x10010000 > devmem: mmap: Operation not permitted > $ devmem 0x80200000 > devmem: mmap: Operation not permitted > > Signed-off-by: Zong Li <zong.li@sifive.com> > --- > arch/riscv/Kconfig | 1 + > arch/riscv/include/asm/io.h | 2 ++ > arch/riscv/mm/init.c | 19 +++++++++++++++++++ > 3 files changed, 22 insertions(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 128192e14ff2..ffd7841ede4c 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -16,6 +16,7 @@ config RISCV > select ARCH_HAS_BINFMT_FLAT > select ARCH_HAS_DEBUG_VIRTUAL if MMU > select ARCH_HAS_DEBUG_WX > + select ARCH_HAS_DEVMEM_IS_ALLOWED > select ARCH_HAS_GCOV_PROFILE_ALL > select ARCH_HAS_GIGANTIC_PAGE > select ARCH_HAS_MMIOWB > diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h > index 3835c3295dc5..04ac65ab93ce 100644 > --- a/arch/riscv/include/asm/io.h > +++ b/arch/riscv/include/asm/io.h > @@ -147,4 +147,6 @@ __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw()) > > #include <asm-generic/io.h> > > +extern int devmem_is_allowed(unsigned long pfn); > + > #endif /* _ASM_RISCV_IO_H */ > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index bbe816e03b2f..5e7e61519acc 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -517,6 +517,25 @@ void mark_rodata_ro(void) > } > #endif > > +#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. > + * > + * Disallow 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 > + > void __init resource_init(void) > { > struct memblock_region *region; ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM 2020-07-09 20:08 ` Palmer Dabbelt @ 2020-07-10 2:43 ` Zong Li 0 siblings, 0 replies; 13+ messages in thread From: Zong Li @ 2020-07-10 2:43 UTC (permalink / raw) To: Palmer Dabbelt Cc: Paul Walmsley, linux-riscv, linux-kernel@vger.kernel.org List On Fri, Jul 10, 2020 at 4:08 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > On Tue, 16 Jun 2020 00:45:47 PDT (-0700), zong.li@sifive.com wrote: > > Implement the 'devmem_is_allowed()' interface for RISC-V, like some of > > other architectures have done. It will be called from range_is_allowed() > > when userpsace attempts to access /dev/mem. > > In fact, it's exactly the same (down to a few words of the comment) to the > others that I checked. I'm going to put a generic version in lib/ instead, > I've sent out the patches. > OK, no problem, thanks for improving it. > > Access to exclusive IOMEM and kernel RAM is denied unless > > CONFIG_STRICT_DEVMEM is set to 'n'. > > > > Test it by devmem, the result as follows: > > > > - CONFIG_STRICT_DEVMEM=y > > $ devmem 0x10010000 > > 0x00000000 > > $ devmem 0x80200000 > > 0x0000106F > > > > - CONFIG_STRICT_DEVMEM is not set > > $ devmem 0x10010000 > > devmem: mmap: Operation not permitted > > $ devmem 0x80200000 > > devmem: mmap: Operation not permitted > > > > Signed-off-by: Zong Li <zong.li@sifive.com> > > --- > > arch/riscv/Kconfig | 1 + > > arch/riscv/include/asm/io.h | 2 ++ > > arch/riscv/mm/init.c | 19 +++++++++++++++++++ > > 3 files changed, 22 insertions(+) > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 128192e14ff2..ffd7841ede4c 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -16,6 +16,7 @@ config RISCV > > select ARCH_HAS_BINFMT_FLAT > > select ARCH_HAS_DEBUG_VIRTUAL if MMU > > select ARCH_HAS_DEBUG_WX > > + select ARCH_HAS_DEVMEM_IS_ALLOWED > > select ARCH_HAS_GCOV_PROFILE_ALL > > select ARCH_HAS_GIGANTIC_PAGE > > select ARCH_HAS_MMIOWB > > diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h > > index 3835c3295dc5..04ac65ab93ce 100644 > > --- a/arch/riscv/include/asm/io.h > > +++ b/arch/riscv/include/asm/io.h > > @@ -147,4 +147,6 @@ __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw()) > > > > #include <asm-generic/io.h> > > > > +extern int devmem_is_allowed(unsigned long pfn); > > + > > #endif /* _ASM_RISCV_IO_H */ > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > index bbe816e03b2f..5e7e61519acc 100644 > > --- a/arch/riscv/mm/init.c > > +++ b/arch/riscv/mm/init.c > > @@ -517,6 +517,25 @@ void mark_rodata_ro(void) > > } > > #endif > > > > +#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. > > + * > > + * Disallow 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 > > + > > void __init resource_init(void) > > { > > struct memblock_region *region; ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2020-07-10 2:44 UTC | newest] Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-06-16 7:45 [PATCH 0/2] Add STRICT_DEVMEM support on RISC-V Zong Li 2020-06-16 7:45 ` [PATCH 1/2] riscv: Register System RAM as iomem resources Zong Li 2020-06-16 11:51 ` Nick Kossifidis 2020-06-17 1:23 ` Zong Li 2020-07-09 18:27 ` Palmer Dabbelt 2020-07-10 2:05 ` Nick Kossifidis 2020-06-16 7:45 ` [PATCH 2/2] riscv: Support CONFIG_STRICT_DEVMEM Zong Li 2020-06-16 12:27 ` Nick Kossifidis 2020-06-17 1:56 ` Zong Li 2020-06-17 5:28 ` Nick Kossifidis 2020-06-17 6:32 ` Zong Li 2020-07-09 20:08 ` Palmer Dabbelt 2020-07-10 2:43 ` Zong Li
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