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* riscv: fix race when vmap stack overflowJisheng Zhang2022-11-291-0/+1
| | | | | | | | | | | | | | | | | | | | | Currently, when detecting vmap stack overflow, riscv firstly switches to the so called shadow stack, then use this shadow stack to call the get_overflow_stack() to get the overflow stack. However, there's a race here if two or more harts use the same shadow stack at the same time. To solve this race, we introduce spin_shadow_stack atomic var, which will be swap between its own address and 0 in atomic way, when the var is set, it means the shadow_stack is being used; when the var is cleared, it means the shadow_stack isn't being used. Fixes: 31da94c25aea ("riscv: add VMAP_STACK overflow detection") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Suggested-by: Guo Ren <guoren@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20221030124517.2370-1-jszhang@kernel.org [Palmer: Add AQ to the swap, and also some comments.] Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* riscv: add VMAP_STACK overflow detectionTong Tiangen2021-07-062-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds stack overflow detection to riscv, usable when CONFIG_VMAP_STACK=y. Overflow is detected in kernel exception entry(kernel/entry.S), if the kernel stack is overflow and been detected, the overflow handler is invoked on a per-cpu overflow stack. This approach preserves GPRs and the original exception information. The overflow detect is performed before any attempt is made to access the stack and the principle of stack overflow detection: kernel stacks are aligned to double their size, enabling overflow to be detected with a single bit test. For example, a 16K stack is aligned to 32K, ensuring that bit 14 of the SP must be zero. On an overflow (or underflow), this bit is flipped. Thus, overflow (of less than the size of the stack) can be detected by testing whether this bit is set. This gives us a useful error message on stack overflow, as can be trigger with the LKDTM overflow test: [ 388.053267] lkdtm: Performing direct entry EXHAUST_STACK [ 388.053663] lkdtm: Calling function with 1024 frame size to depth 32 ... [ 388.054016] lkdtm: loop 32/32 ... [ 388.054186] lkdtm: loop 31/32 ... [ 388.054491] lkdtm: loop 30/32 ... [ 388.054672] lkdtm: loop 29/32 ... [ 388.054859] lkdtm: loop 28/32 ... [ 388.055010] lkdtm: loop 27/32 ... [ 388.055163] lkdtm: loop 26/32 ... [ 388.055309] lkdtm: loop 25/32 ... [ 388.055481] lkdtm: loop 24/32 ... [ 388.055653] lkdtm: loop 23/32 ... [ 388.055837] lkdtm: loop 22/32 ... [ 388.056015] lkdtm: loop 21/32 ... [ 388.056188] lkdtm: loop 20/32 ... [ 388.058145] Insufficient stack space to handle exception! [ 388.058153] Task stack: [0xffffffd014260000..0xffffffd014264000] [ 388.058160] Overflow stack: [0xffffffe1f8d2c220..0xffffffe1f8d2d220] [ 388.058168] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90 [ 388.058175] Hardware name: riscv-virtio,qemu (DT) [ 388.058187] epc : number+0x32/0x2c0 [ 388.058247] ra : vsnprintf+0x2ae/0x3f0 [ 388.058255] epc : ffffffe0002d38f6 ra : ffffffe0002d814e sp : ffffffd01425ffc0 [ 388.058263] gp : ffffffe0012e4010 tp : ffffffe08014da00 t0 : ffffffd0142606e8 [ 388.058271] t1 : 0000000000000000 t2 : 0000000000000000 s0 : ffffffd014260070 [ 388.058303] s1 : ffffffd014260158 a0 : ffffffd01426015e a1 : ffffffd014260158 [ 388.058311] a2 : 0000000000000013 a3 : ffff0a01ffffff10 a4 : ffffffe000c398e0 [ 388.058319] a5 : 511b02ec65f3e300 a6 : 0000000000a1749a a7 : 0000000000000000 [ 388.058327] s2 : ffffffff000000ff s3 : 00000000ffff0a01 s4 : ffffffe0012e50a8 [ 388.058335] s5 : 0000000000ffff0a s6 : ffffffe0012e50a8 s7 : ffffffe000da1cc0 [ 388.058343] s8 : ffffffffffffffff s9 : ffffffd0142602b0 s10: ffffffd0142602a8 [ 388.058351] s11: ffffffd01426015e t3 : 00000000000f0000 t4 : ffffffffffffffff [ 388.058359] t5 : 000000000000002f t6 : ffffffd014260158 [ 388.058366] status: 0000000000000100 badaddr: ffffffd01425fff8 cause: 000000000000000f [ 388.058374] Kernel panic - not syncing: Kernel stack overflow [ 388.058381] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90 [ 388.058387] Hardware name: riscv-virtio,qemu (DT) [ 388.058393] Call Trace: [ 388.058400] [<ffffffe000004944>] walk_stackframe+0x0/0xce [ 388.058406] [<ffffffe0006f0b28>] dump_backtrace+0x38/0x46 [ 388.058412] [<ffffffe0006f0b46>] show_stack+0x10/0x18 [ 388.058418] [<ffffffe0006f3690>] dump_stack+0x74/0x8e [ 388.058424] [<ffffffe0006f0d52>] panic+0xfc/0x2b2 [ 388.058430] [<ffffffe0006f0acc>] print_trace_address+0x0/0x24 [ 388.058436] [<ffffffe0002d814e>] vsnprintf+0x2ae/0x3f0 [ 388.058956] SMP: stopping secondary CPUs Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* riscv: ptrace: add argn syntaxJeff Xie2021-07-051-0/+31
| | | | | | | | This enables ftrace kprobe events to access kernel function arguments via $argN syntax. Signed-off-by: Jeff Xie <huan.xie@suse.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* riscv: mm: fix build errors caused by mk_pmd()Nanyong Sun2021-07-052-5/+2
| | | | | | | | | | | | | | | | | | | | | | | With "riscv: mm: add THP support on 64-bit", mk_pmd() function introduce build errors, 1.build with CONFIG_ARCH_RV32I=y: arch/riscv/include/asm/pgtable.h: In function 'mk_pmd': arch/riscv/include/asm/pgtable.h:513:9: error: implicit declaration of function 'pfn_pmd'; did you mean 'pfn_pgd'? [-Werror=implicit-function-declaration] 2.build with CONFIG_SPARSEMEM=y && CONFIG_SPARSEMEM_VMEMMAP=n arch/riscv/include/asm/pgtable.h: In function 'mk_pmd': include/asm-generic/memory_model.h:64:14: error: implicit declaration of function 'page_to_section'; did you mean 'present_section'? [-Werror=implicit-function-declaration] Move the definition of mk_pmd to pgtable-64.h to fix the first error. Use macro definition instead of inline function for mk_pmd to fix the second problem. It is similar to the mk_pte macro. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* riscv: Introduce structure that group all variables regarding kernel mappingAlexandre Ghiti2021-07-051-24/+30
| | | | | | | | | | | We have a lot of variables that are used to hold kernel mapping addresses, offsets between physical and virtual mappings and some others used for XIP kernels: they are all defined at different places in mm/init.c, so group them into a single structure with, for some of them, more explicit and concise names. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* Merge branch 'riscv-wx-mappings' into for-nextPalmer Dabbelt2021-06-304-20/+50
|\ | | | | | | | | | | | | | | | | | | | | | | This contains both the short-term fix for the W+X boot mappings and the larger cleanup. * riscv-wx-mappings: riscv: Map the kernel with correct permissions the first time riscv: Introduce set_kernel_memory helper riscv: Simplify xip and !xip kernel address conversion macros riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED riscv: mm: Fix W+X mappings at boot
| * riscv: Map the kernel with correct permissions the first timeAlexandre Ghiti2021-06-303-9/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For 64-bit kernels, we map all the kernel with write and execute permissions and afterwards remove writability from text and executability from data. For 32-bit kernels, the kernel mapping resides in the linear mapping, so we map all the linear mapping as writable and executable and afterwards we remove those properties for unused memory and kernel mapping as described above. Change this behavior to directly map the kernel with correct permissions and avoid going through the whole mapping to fix the permissions. At the same time, this fixes an issue introduced by commit 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear mapping") as reported here https://github.com/starfive-tech/linux/issues/17. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Introduce set_kernel_memory helperAlexandre Ghiti2021-06-301-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | This helper should be used for setting permissions to the kernel mapping as it takes pointers as arguments and then avoids explicit cast to unsigned long needed for the set_memory_* API. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Simplify xip and !xip kernel address conversion macrosAlexandre Ghiti2021-06-112-11/+5
| | | | | | | | | | | | | | | | | | | | To simplify the kernel address conversion code, make the same definition of kernel_mapping_pa_to_va and kernel_mapping_va_to_pa compatible for both xip and !xip kernel by defining XIP_OFFSET to 0 in !xip kernel. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: Enable KFENCE for riscv64Liu Shixin2021-06-301-0/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add architecture specific implementation details for KFENCE and enable KFENCE for the riscv64 architecture. In particular, this implements the required interface in <asm/kfence.h>. KFENCE requires that attributes for pages from its memory pool can individually be set. Therefore, force the kfence pool to be mapped at page granularity. Testing this patch using the testcases in kfence_test.c and all passed. Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: Marco Elver <elver@google.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | RISC-V: Use asm-generic for {in,out}{bwlq}Palmer Dabbelt2021-06-301-13/+0
| | | | | | | | | | | | | | | | | | The asm-generic implementation is functionally identical to the RISC-V version. Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: add ASID-based tlbflushing methodsGuo Ren2021-06-301-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement optimized version of the tlb flushing routines for systems using ASIDs. These are behind the use_asid_allocator static branch to not affect existing systems not using ASIDs. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> [hch: rebased on top of previous cleanups, use the same algorithm as the non-ASID based code for local vs global flushes, keep functions as local as possible] Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Guo Ren <guoren@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: Cleanup unused functionsGuo Ren2021-06-081-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | These functions haven't been used, so just remove them. The patch has been tested with riscv. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: fix build error when CONFIG_SMP is disabledBixuan Cui2021-06-082-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix build error when disable CONFIG_SMP: mm/pgtable-generic.o: In function `.L19': pgtable-generic.c:(.text+0x42): undefined reference to `flush_pmd_tlb_range' mm/pgtable-generic.o: In function `pmdp_huge_clear_flush': pgtable-generic.c:(.text+0x6c): undefined reference to `flush_pmd_tlb_range' mm/pgtable-generic.o: In function `pmdp_invalidate': pgtable-generic.c:(.text+0x162): undefined reference to `flush_pmd_tlb_range' Fixes: e88b333142e4 ("riscv: mm: add THP support on 64-bit") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Bixuan Cui <cuibixuan@huawei.com> Acked-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: Use global mappings for kernel pagesGuo Ren2021-05-291-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | We map kernel pages into all addresses spages, so they can be marked as global. This allows hardware to avoid flushing the kernel mappings when moving between address spaces. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> [Palmer: commit text] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: mm: init: Consolidate vars, functionsJisheng Zhang2021-05-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Consolidate the following items in init.c Staticize global vars as much as possible; Add __initdata mark if the global var isn't needed after init Add __init mark if the func isn't needed after init Add __ro_after_init if the global var is read only after init Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: kprobes: Remove redundant kprobe_step_ctxJisheng Zhang2021-05-291-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Inspired by commit ba090f9cafd5 ("arm64: kprobes: Remove redundant kprobe_step_ctx"), the ss_pending and match_addr of kprobe_step_ctx are redundant because those can be replaced by KPROBE_HIT_SS and &cur_kprobe->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) respectively. Remove the kprobe_step_ctx to simplify the code. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: Turn has_fpu into a static key if FPU=yJisheng Zhang2021-05-251-3/+8
| | | | | | | | | | | | | | | | | | The has_fpu check sits at hot code path: switch_to(). Currently, has_fpu is a bool variable if FPU=y, switch_to() checks it each time, we can optimize out this check by turning the has_fpu into a static key. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: Move setup_bootmem into paging_initKefeng Wang2021-05-251-1/+0
| | | | | | | | | | | | | | Make setup_bootmem() static. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: enable generic PCI resource mappingStanislaw Kardach2021-05-251-0/+2
| | | | | | | | | | | | | | | | | | | | | | Enable the PCI resource mapping on RISC-V using the generic framework. This allows userspace applications to mmap PCI resources using /sys/devices/pci*/*/resource* interface. The mmap has been tested with Intel x520-DA2 NIC card on a HiFive Unmatched board (SiFive FU740 SoC). Signed-off-by: Stanislaw Kardach <kda@semihalf.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: mremap speedup - enable HAVE_MOVE_PUD and HAVE_MOVE_PMDJisheng Zhang2021-05-251-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | HAVE_MOVE_PUD enables remapping pages at the PUD level if both the source and destination addresses are PUD-aligned. HAVE_MOVE_PMD does similar speedup on the PMD level. With HAVE_MOVE_PUD enabled, there is about a 143x improvement on qemu With HAVE_MOVE_PMD enabled, there is about a 5x improvement on qemu Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: mm: add THP support on 64-bitNanyong Sun2021-05-221-0/+156
| | | | | | | | | | | | | | | | Bring Transparent HugePage support to riscv. A transparent huge page is always represented as a pmd. Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: mm: make pmd_bad() check leaf conditionNanyong Sun2021-05-221-1/+1
| | | | | | | | | | | | | | | | | | In the definition in Documentation/vm/arch_pgtable_helpers.rst, pmd_bad() means test a non-table mapped PMD, so it should also return true when it is a leaf page. Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: mm: add _PAGE_LEAF macroNanyong Sun2021-05-223-6/+8
|/ | | | | | | | | | | In riscv, a page table entry is leaf when any bit of read, write, or execute bit is set. So add a macro:_PAGE_LEAF instead of (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC), which is frequently used to determine if it is a leaf page. This make code easier to read, without any functional change. Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* riscv: Consistify protect_kernel_linear_mapping_text_rodata() useGeert Uytterhoeven2021-05-061-1/+6
| | | | | | | | | | | | | | | | | | | The various uses of protect_kernel_linear_mapping_text_rodata() are not consistent: - Its definition depends on "64BIT && !XIP_KERNEL", - Its forward declaration depends on MMU, - Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU && !XIP_KERNEL". Fix this by settling on the dependencies of the caller, which can be simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL". Provide a dummy definition, as the caller is protected by "IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef CONFIG_STRICT_KERNEL_RWX". Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* Merge tag 'riscv-for-linus-5.13-mw0' of ↵Linus Torvalds2021-05-0618-17/+424
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for the memtest= kernel command-line argument. - Support for building the kernel with FORTIFY_SOURCE. - Support for generic clockevent broadcasts. - Support for the buildtar build target. - Some build system cleanups to pass more LLVM-friendly arguments. - Support for kprobes. - A rearranged kernel memory map, the first part of supporting sv48 systems. - Improvements to kexec, along with support for kdump and crash kernels. - An alternatives-based errata framework, along with support for handling a pair of errata that manifest on some SiFive designs (including the HiFive Unmatched). - Support for XIP. - A device tree for the Microchip PolarFire ICICLE SoC and associated dev board. ... along with a bunch of cleanups. There are already a handful of fixes on the list so there will likely be a part 2. * tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (45 commits) RISC-V: Always define XIP_FIXUP riscv: Remove 32b kernel mapping from page table dump riscv: Fix 32b kernel build with CONFIG_DEBUG_VIRTUAL=y RISC-V: Fix error code returned by riscv_hartid_to_cpuid() RISC-V: Enable Microchip PolarFire ICICLE SoC RISC-V: Initial DTS for Microchip ICICLE board dt-bindings: riscv: microchip: Add YAML documentation for the PolarFire SoC RISC-V: Add Microchip PolarFire SoC kconfig option RISC-V: enable XIP RISC-V: Add crash kernel support RISC-V: Add kdump support RISC-V: Improve init_resources() RISC-V: Add kexec support RISC-V: Add EM_RISCV to kexec UAPI header riscv: vdso: fix and clean-up Makefile riscv/mm: Use BUG_ON instead of if condition followed by BUG. riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe riscv: Set ARCH_HAS_STRICT_MODULE_RWX if MMU riscv: module: Create module allocations without exec permissions riscv: bpf: Avoid breaking W^X ...
| * RISC-V: Always define XIP_FIXUPPalmer Dabbelt2021-05-011-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | XIP depends on MMU, but XIP_FIXUP is used throughout the kernel in order to avoid excessive ifdefs. This just makes sure to always define XIP_FIXUP, which will fix MMU=n builds. XIP_OFFSET is used by assembly but XIP_FIXUP is C-only, so they're split. Fixes: 44c922572952 ("RISC-V: enable XIP") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> Tested-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Fix 32b kernel build with CONFIG_DEBUG_VIRTUAL=yAlexandre Ghiti2021-05-011-1/+1
| | | | | | | | | | | | | | | | | | Declare kernel_virt_addr for 32b kernel since it is used in __phys_addr_symbol defined when CONFIG_DEBUG_VIRTUAL is set. Fixes: 2bfc6cd81bd17 ("riscv: Move kernel mapping outside of linear mapping") Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * RISC-V: enable XIPVitaly Wool2021-04-262-2/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce XIP (eXecute In Place) support for RISC-V platforms. It allows code to be executed directly from non-volatile storage directly addressable by the CPU, such as QSPI NOR flash which can be found on many RISC-V platforms. This makes way for significant optimization of RAM footprint. The XIP kernel is not compressed since it has to run directly from flash, so it will occupy more space on the non-volatile storage. The physical flash address used to link the kernel object files and for storing it has to be known at compile time and is represented by a Kconfig option. XIP on RISC-V will for the time being only work on MMU-enabled kernels. Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com> [Alex: Rebase on top of "Move kernel mapping outside the linear mapping" ] Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> [Palmer: disable XIP for allyesconfig] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * RISC-V: Add kdump supportNick Kossifidis2021-04-262-6/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for kdump, the kernel will reserve a region for the crash kernel and jump there on panic. In order for userspace tools (kexec-tools) to prepare the crash kernel kexec image, we also need to expose some information on /proc/iomem for the memory regions used by the kernel and for the region reserved for crash kernel. Note that on userspace the device tree is used to determine the system's memory layout so the "System RAM" on /proc/iomem is ignored. I tested this on riscv64 qemu and works as expected, you may test it by triggering a crash through /proc/sysrq_trigger: echo c > /proc/sysrq_trigger Signed-off-by: Nick Kossifidis <mick@ics.forth.gr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * RISC-V: Add kexec supportNick Kossifidis2021-04-261-0/+49
| | | | | | | | | | | | | | | | | | | | This patch adds support for kexec on RISC-V. On SMP systems it depends on HOTPLUG_CPU in order to be able to bring up all harts after kexec. It also needs a recent OpenSBI version that supports the HSM extension. I tested it on riscv64 QEMU on both an smp and a non-smp system. Signed-off-by: Nick Kossifidis <mick@ics.forth.gr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Constify sbi_ipi_opsJisheng Zhang2021-04-261-2/+2
| | | | | | | | | | | | | | | | | | Constify the sbi_ipi_ops so that it will be placed in the .rodata section. This will cause attempts to modify it to fail when strict page permissions are in place. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Constify sys_call_tableJisheng Zhang2021-04-261-1/+1
| | | | | | | | | | | | | | | | | | Constify the sys_call_table so that it will be placed in the .rodata section. This will cause attempts to modify the table to fail when strict page permissions are in place. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Move kernel mapping outside of linear mappingAlexandre Ghiti2021-04-263-10/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparatory patch for relocatable kernel and sv48 support. The kernel used to be linked at PAGE_OFFSET address therefore we could use the linear mapping for the kernel mapping. But the relocated kernel base address will be different from PAGE_OFFSET and since in the linear mapping, two different virtual addresses cannot point to the same physical address, the kernel mapping needs to lie outside the linear mapping so that we don't have to copy it at the same physical offset. The kernel mapping is moved to the last 2GB of the address space, BPF is now always after the kernel and modules use the 2GB memory range right before the kernel, so BPF and modules regions do not overlap. KASLR implementation will simply have to move the kernel in the last 2GB range and just take care of leaving enough space for BPF. In addition, by moving the kernel to the end of the address space, both sv39 and sv48 kernels will be exactly the same without needing to be relocated at runtime. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> [Palmer: Squash the STRICT_RWX fix, and a !MMU fix] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Workaround mcount name prior to clang-13Nathan Chancellor2021-04-261-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to clang 13.0.0, the RISC-V name for the mcount symbol was "mcount", which differs from the GCC version of "_mcount", which results in the following errors: riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_level': main.c:(.text+0xe): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_start': main.c:(.text+0x4e): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_finish': main.c:(.text+0x92): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `.LBB32_28': main.c:(.text+0x30c): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `free_initmem': main.c:(.text+0x54c): undefined reference to `mcount' This has been corrected in https://reviews.llvm.org/D98881 but the minimum supported clang version is 10.0.1. To avoid build errors and to gain a working function tracer, adjust the name of the mcount symbol for older versions of clang in mount.S and recordmcount.pl. Link: https://github.com/ClangBuiltLinux/linux/issues/1331 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: sifive: Apply errata "cip-1200" patchVincent Chen2021-04-262-2/+11
| | | | | | | | | | | | | | | | | | | | | | For certain SiFive CPUs, "sfence.vma addr" cannot exactly flush addr from TLB in the particular cases. The details could be found here: https://sifive.cdn.prismic.io/sifive/167a1a56-03f4-4615-a79e-b2a86153148f_FU740_errata_20210205.pdf In order to ensure the functionality, this patch uses the Alternative scheme to replace all "sfence.vma addr" with "sfence.vma" at runtime. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: sifive: Apply errata "cip-453" patchVincent Chen2021-04-261-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add sign extension to the $badaddr before addressing the instruction page fault and instruction access fault to workaround the issue "cip-453". To avoid affecting the existing code sequence, this patch will creates two trampolines to add sign extension to the $badaddr. By the "alternative" mechanism, these two trampolines will replace the original exception handler of instruction page fault and instruction access fault in the excp_vect_table. In this case, only the specific SiFive CPU core jumps to the do_page_fault and do_trap_insn_fault through these two trampolines. Other CPUs are not affected. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: sifive: Add SiFive alternative portsVincent Chen2021-04-261-0/+3
| | | | | | | | | | | | | | | | Add required ports of the Alternative scheme for SiFive. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Introduce alternative mechanism to apply errata solutionVincent Chen2021-04-267-0/+205
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce the "alternative" mechanism from ARM64 and x86 to apply the CPU vendors' errata solution at runtime. The main purpose of this patch is to provide a framework. Therefore, the implementation is quite basic for now so that some scenarios could not use this schemei, such as patching code to a module, relocating the patching code and heterogeneous CPU topology. Users could use the macro ALTERNATIVE to apply an errata to the existing code flow. In the macro ALTERNATIVE, users need to specify the manufacturer information(vendorid, archid, and impid) for this errata. Therefore, kernel will know this errata is suitable for which CPU core. During the booting procedure, kernel will select the errata required by the CPU core and then patch it. It means that the kernel only applies the errata to the specified CPU core. In this case, the vendor's errata does not affect each other at runtime. The above patching procedure only occurs during the booting phase, so we only take the overhead of the "alternative" mechanism once. This "alternative" mechanism is enabled by default to ensure that all required errata will be applied. However, users can disable this feature by the Kconfig "CONFIG_RISCV_ERRATA_ALTERNATIVE". Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Add 3 SBI wrapper functions to get cpu manufacturer informationVincent Chen2021-04-261-0/+3
| | | | | | | | | | | | | | | | | | Add 3 wrapper functions to get vendor id, architecture id and implement id from M-mode Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * riscv: Add ARCH_HAS_FORTIFY_SOURCEKefeng Wang2021-03-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | FORTIFY_SOURCE could detect various overflows at compile and run time. ARCH_HAS_FORTIFY_SOURCE means that the architecture can be built and run with CONFIG_FORTIFY_SOURCE. Select it in RISCV. See more about this feature from commit 6974f0c4555e ("include/linux/string.h: add the option of fortified string.h functions"). Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | Merge branch 'work.misc' of ↵Linus Torvalds2021-05-021-1/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted stuff all over the place" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: useful constants: struct qstr for ".." hostfs_open(): don't open-code file_dentry() whack-a-mole: kill strlen_user() (again) autofs: should_expire() argument is guaranteed to be positive apparmor:match_mn() - constify devpath argument buffer: a small optimization in grow_buffers get rid of autofs_getpath() constify dentry argument of dentry_path()/dentry_path_raw()
| * | whack-a-mole: kill strlen_user() (again)Al Viro2021-03-271-1/+0
| |/ | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | riscv: evaluate put_user() arg before enabling user accessBen Dooks2021-04-011-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The <asm/uaccess.h> header has a problem with put_user(a, ptr) if the 'a' is not a simple variable, such as a function. This can lead to the compiler producing code as so: 1: enable_user_access() 2: evaluate 'a' into register 'r' 3: put 'r' to 'ptr' 4: disable_user_acess() The issue is that 'a' is now being evaluated with the user memory protections disabled. So we try and force the evaulation by assigning 'x' to __val at the start, and hoping the compiler barriers in enable_user_access() do the job of ordering step 2 before step 1. This has shown up in a bug where 'a' sleeps and thus schedules out and loses the SR_SUM flag. This isn't sufficient to fully fix, but should reduce the window of opportunity. The first instance of this we found is in scheudle_tail() where the code does: $ less -N kernel/sched/core.c 4263 if (current->set_child_tid) 4264 put_user(task_pid_vnr(current), current->set_child_tid); Here, the task_pid_vnr(current) is called within the block that has enabled the user memory access. This can be made worse with KASAN which makes task_pid_vnr() a rather large call with plenty of opportunity to sleep. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Reported-by: syzbot+e74b94fe601ab9552d69@syzkaller.appspotmail.com Suggested-by: Arnd Bergman <arnd@arndb.de> -- Changes since v1: - fixed formatting and updated the patch description with more info Changes since v2: - fixed commenting on __put_user() (schwab@linux-m68k.org) Change since v3: - fixed RFC in patch title. Should be ready to merge. Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: process: Fix no prototype for arch_dup_task_structNanyong Sun2021-03-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | Fix the following W=1 compilation warning: arch/riscv/kernel/process.c:114:5: warning: no previous prototype for ‘arch_dup_task_struct’ [-Wmissing-prototypes] 114 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) | ^~~~~~~~~~~~~~~~~~~~ Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: time: Fix no prototype for time_initNanyong Sun2021-03-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | Fix the following W=1 compilation warning: arch/riscv/kernel/time.c:16:13: warning: no previous prototype for ‘time_init’ [-Wmissing-prototypes] 16 | void __init time_init(void) | ^~~~~~~~~ Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: ptrace: Fix no prototype warningsNanyong Sun2021-03-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the following W=1 kernel compilation warnings: arch/riscv/kernel/ftrace.c:186:6: warning: no previous prototype for ‘prepare_ftrace_return’ [-Wmissing-prototypes] 186 | void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, | ^~~~~~~~~~~~~~~~~~~~~ arch/riscv/kernel/ptrace.c:239:15: warning: no previous prototype for ‘do_syscall_trace_enter’ [-Wmissing-prototypes] 239 | __visible int do_syscall_trace_enter(struct pt_regs *regs) | ^~~~~~~~~~~~~~~~~~~~~~ arch/riscv/kernel/ptrace.c:262:16: warning: no previous prototype for ‘do_syscall_trace_exit’ [-Wmissing-prototypes] 262 | __visible void do_syscall_trace_exit(struct pt_regs *regs) | ^~~~~~~~~~~~~~~~~~~~~ Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: irq: Fix no prototype warningNanyong Sun2021-03-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | Fix the following W=1 kernel compilation warning: arch/riscv/kernel/irq.c:19:13: warning: no previous prototype for ‘init_IRQ’ [-Wmissing-prototypes] 19 | void __init init_IRQ(void) | ^~~~~~~~ Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | riscv: traps: Fix no prototype warningsNanyong Sun2021-03-091-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix all W=1 compilation warnings:'no previous prototype for' in arch/riscv/kernel/traps.c: arch/riscv/kernel/traps.c:96:15: warning: no previous prototype for ‘do_trap_unknown’ [-Wmissing-prototypes] 96 | DO_ERROR_INFO(do_trap_unknown, | ^~~~~~~~~~~~~~~ arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’ 91 | asmlinkage __visible void name(struct pt_regs *regs) \ | ^~~~ arch/riscv/kernel/traps.c:98:15: warning: no previous prototype for ‘do_trap_insn_misaligned’ [-Wmissing-prototypes] 98 | DO_ERROR_INFO(do_trap_insn_misaligned, | ^~~~~~~~~~~~~~~~~~~~~~~ arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’ 91 | asmlinkage __visible void name(struct pt_regs *regs) \ | ^~~~ arch/riscv/kernel/traps.c:100:15: warning: no previous prototype for ‘do_trap_insn_fault’ [-Wmissing-prototypes] ... Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> [Palmer: fix checkpatch warnings] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | RISC-V: correct enum sbi_ext_rfence_fidHeinrich Schuchardt2021-03-091-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | The constants in enum sbi_ext_rfence_fid should match the SBI specification. See https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc#78-function-listing | Function Name | FID | EID | sbi_remote_fence_i | 0 | 0x52464E43 | sbi_remote_sfence_vma | 1 | 0x52464E43 | sbi_remote_sfence_vma_asid | 2 | 0x52464E43 | sbi_remote_hfence_gvma_vmid | 3 | 0x52464E43 | sbi_remote_hfence_gvma | 4 | 0x52464E43 | sbi_remote_hfence_vvma_asid | 5 | 0x52464E43 | sbi_remote_hfence_vvma | 6 | 0x52464E43 Fixes: ecbacc2a3efd ("RISC-V: Add SBI v0.2 extension definitions") Reported-by: Sean Anderson <seanga2@gmail.com> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>