kernel.git/arch/riscv/kernel/setup.c, branch linux-6.0.y

riscv: mm: Proper page permissions after initmem free

2022-12-08T10:30:18Z

commit 6fdd5d2f8c2f54b7fad4ff4df2a19542aeaf6102 upstream. 64-bit RISC-V kernels have the kernel image mapped separately to alias the linear map. The linear map and the kernel image map are documented as "direct mapping" and "kernel" respectively in [1]. At image load time, the linear map corresponding to the kernel image is set to PAGE_READ permission, and the kernel image map is set to PAGE_READ|PAGE_EXEC. When the initmem is freed, the pages in the linear map should be restored to PAGE_READ|PAGE_WRITE, whereas the corresponding pages in the kernel image map should be restored to PAGE_READ, by removing the PAGE_EXEC permission. This is not the case. For 64-bit kernels, only the linear map is restored to its proper page permissions at initmem free, and not the kernel image map. In practise this results in that the kernel can potentially jump to dead __init code, and start executing invalid instructions, without getting an exception. Restore the freed initmem properly, by setting both the kernel image map to the correct permissions. [1] Documentation/riscv/vm-layout.rst Fixes: e5c35fa04019 ("riscv: Map the kernel with correct permissions the first time") Signed-off-by: Björn Töpel Reviewed-by: Alexandre Ghiti Tested-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20221115090641.258476-1-bjorn@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman

riscv: fix reserved memory setup

2022-11-16T09:04:04Z

[ Upstream commit 50e63dd8ed92045eb70a72d7ec725488320fb68b ] Currently, RISC-V sets up reserved memory using the "early" copy of the device tree. As a result, when trying to get a reserved memory region using of_reserved_mem_lookup(), the pointer to reserved memory regions is using the early, pre-virtual-memory address which causes a kernel panic when trying to use the buffer's name: Unable to handle kernel paging request at virtual address 00000000401c31ac Oops [#1] Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc1-00001-g0d9d6953d834 #1 Hardware name: Microchip PolarFire-SoC Icicle Kit (DT) epc : string+0x4a/0xea ra : vsnprintf+0x1e4/0x336 epc : ffffffff80335ea0 ra : ffffffff80338936 sp : ffffffff81203be0 gp : ffffffff812e0a98 tp : ffffffff8120de40 t0 : 0000000000000000 t1 : ffffffff81203e28 t2 : 7265736572203a46 s0 : ffffffff81203c20 s1 : ffffffff81203e28 a0 : ffffffff81203d22 a1 : 0000000000000000 a2 : ffffffff81203d08 a3 : 0000000081203d21 a4 : ffffffffffffffff a5 : 00000000401c31ac a6 : ffff0a00ffffff04 a7 : ffffffffffffffff s2 : ffffffff81203d08 s3 : ffffffff81203d00 s4 : 0000000000000008 s5 : ffffffff000000ff s6 : 0000000000ffffff s7 : 00000000ffffff00 s8 : ffffffff80d9821a s9 : ffffffff81203d22 s10: 0000000000000002 s11: ffffffff80d9821c t3 : ffffffff812f3617 t4 : ffffffff812f3617 t5 : ffffffff812f3618 t6 : ffffffff81203d08 status: 0000000200000100 badaddr: 00000000401c31ac cause: 000000000000000d [] vsnprintf+0x1e4/0x336 [] vprintk_store+0xf6/0x344 [] vprintk_emit+0x56/0x192 [] vprintk_default+0x16/0x1e [] vprintk+0x72/0x80 [] _printk+0x36/0x50 [] print_reserved_mem+0x1c/0x24 [] paging_init+0x528/0x5bc [] setup_arch+0xd0/0x592 [] start_kernel+0x82/0x73c early_init_fdt_scan_reserved_mem() takes no arguments as it operates on initial_boot_params, which is populated by early_init_dt_verify(). On RISC-V, early_init_dt_verify() is called twice. Once, directly, in setup_arch() if CONFIG_BUILTIN_DTB is not enabled and once indirectly, very early in the boot process, by parse_dtb() when it calls early_init_dt_scan_nodes(). This first call uses dtb_early_va to set initial_boot_params, which is not usable later in the boot process when early_init_fdt_scan_reserved_mem() is called. On arm64 for example, the corresponding call to early_init_dt_scan_nodes() uses fixmap addresses and doesn't suffer the same fate. Move early_init_fdt_scan_reserved_mem() further along the boot sequence, after the direct call to early_init_dt_verify() in setup_arch() so that the names use the correct virtual memory addresses. The above supposed that CONFIG_BUILTIN_DTB was not set, but should work equally in the case where it is - unflatted_and_copy_device_tree() also updates initial_boot_params. Reported-by: Valentina Fernandez Reported-by: Evgenii Shatokhin Link: https://lore.kernel.org/linux-riscv/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/ Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob") Signed-off-by: Conor Dooley Tested-by: Evgenii Shatokhin Link: https://lore.kernel.org/r/20221107151524.3941467-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

riscv: always honor the CONFIG_CMDLINE_FORCE when parsing dtb

2022-10-21T10:37:39Z

commit 10f6913c548b32ecb73801a16b120e761c6957ea upstream. When CONFIG_CMDLINE_FORCE is enabled, cmdline provided by CONFIG_CMDLINE are always used. This allows CONFIG_CMDLINE to be used regardless of the result of device tree scanning. This especially fixes the case where a device tree without the chosen node is supplied to the kernel. In such cases, early_init_dt_scan would return true. But inside early_init_dt_scan_chosen, the cmdline won't be updated as there is no chosen node in the device tree. As a result, CONFIG_CMDLINE is not copied into boot_command_line even if CONFIG_CMDLINE_FORCE is enabled. This commit allows properly update boot_command_line in this situation. Fixes: 8fd6e05c7463 ("arch: riscv: support kernel command line forcing when no DTB passed") Signed-off-by: Wenting Zhang Reviewed-by: Björn Töpel Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/PSBPR04MB399135DFC54928AB958D0638B1829@PSBPR04MB3991.apcprd04.prod.outlook.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman

RISC-V: Clean up the Zicbom block size probing

2022-09-13T09:06:11Z

This fixes two issues: I truncated the warning's hart ID when porting to the 64-bit hart ID code, and the original code's warning handling could fire on an uninitialized hart ID. The biggest change here is that riscv_cbom_block_size is no longer initialized, as IMO the default isn't sane: there's nothing in the ISA that mandates any specific cache block size, so falling back to one will just silently produce the wrong answer on some systems. This also changes the probing order so the cache block size is known before enabling Zicbom support. CC: stable@vger.kernel.org CC: Andrew Jones CC: Heiko Stuebner CC: Atish Patra Fixes: 3aefb2ee5bdd ("riscv: implement Zicbom-based CMO instructions + the t-head variant") Fixes: 1631ba1259d6 ("riscv: Add support for non-coherent devices using zicbom extension") Reported-by: kernel test robot Reported-by: Conor Dooley Signed-off-by: Palmer Dabbelt [Conor: fixed the redefinition errors] Tested-by: Conor Dooley Signed-off-by: Conor Dooley Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220912224800.998121-1-mail@conchuod.ie Signed-off-by: Palmer Dabbelt

riscv: Add support for non-coherent devices using zicbom extension

2022-07-28T22:30:51Z

The Zicbom ISA-extension was ratified in november 2021 and introduces instructions for dcache invalidate, clean and flush operations. Implement cache management operations for non-coherent devices based on them. Of course not all cores will support this, so implement an alternative-based mechanism that replaces empty instructions with ones done around Zicbom instructions. As discussed in previous versions, assume the platform being coherent by default so that non-coherent devices need to get marked accordingly by firmware. Reviewed-by: Christoph Hellwig Signed-off-by: Heiko Stuebner Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de Signed-off-by: Palmer Dabbelt

RISC-V: Mark IORESOURCE_EXCLUSIVE for reserved mem instead of IORESOURCE_BUSY

2022-06-02T05:03:50Z

Commit 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree") marked IORESOURCE_BUSY for reserved memory, which caused resource map failed in subsequent operations of related driver, so remove the IORESOURCE_BUSY flag. In order to prohibit userland mapping reserved memory, mark IORESOURCE_EXCLUSIVE for it. The code to reproduce the issue, dts: mem0: memory@a0000000 { reg = <0x0 0xa0000000 0 0x1000000>; no-map; }; &test { status = "okay"; memory-region = <&mem0>; }; code: np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0); ret = of_address_to_resource(np, 0, &r); base = devm_ioremap_resource(&pdev->dev, &r); // base = -EBUSY Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree") Reported-by: Huaming Jiang Reviewed-by: Guo Ren Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Co-developed-by: Nick Kossifidis Signed-off-by: Xianting Tian Link: https://lore.kernel.org/r/20220518013428.1338983-1-xianting.tian@linux.alibaba.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt

riscv: move boot alternatives to after fill_hwcap

2022-05-12T04:36:32Z

Move the application of boot alternatives to after the hw-capabilities are populated. This allows to check for available extensions when determining which alternatives to apply and also makes it actually work if CONFIG_SMP is disabled for whatever reason. Signed-off-by: Heiko Stuebner Reviewed-by: Christoph Hellwig Reviewed-by: Philipp Tomsich Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20220511192921.2223629-8-heiko@sntech.de Signed-off-by: Palmer Dabbelt

drivers/base/node: consolidate node device subsystem initialization in node_dev_init()

2022-03-22T22:57:10Z

... and call node_dev_init() after memory_dev_init() from driver_init(), so before any of the existing arch/subsys calls. All online nodes should be known at that point: early during boot, arch code determines node and zone ranges and sets the relevant nodes online; usually this happens in setup_arch(). This is in line with memory_dev_init(), which initializes the memory device subsystem and creates all memory block devices. Similar to memory_dev_init(), panic() if anything goes wrong, we don't want to continue with such basic initialization errors. The important part is that node_dev_init() gets called after memory_dev_init() and after cpu_dev_init(), but before any of the relevant archs call register_cpu() to register the new cpu device under the node device. The latter should be the case for the current users of topology_init(). Link: https://lkml.kernel.org/r/20220203105212.30385-1-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Oscar Salvador Tested-by: Anatoly Pugachev (sparc64) Cc: Greg Kroah-Hartman Cc: Michal Hocko Cc: Oscar Salvador Cc: Mike Rapoport Cc: Catalin Marinas Cc: Will Deacon Cc: Thomas Bogendoerfer Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Yoshinori Sato Cc: Rich Felker Cc: "David S. Miller" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

RISC-V: Do not use cpumask data structure for hartid bitmap

2022-01-20T17:27:22Z

Currently, SBI APIs accept a hartmask that is generated from struct cpumask. Cpumask data structure can hold upto NR_CPUs value. Thus, it is not the correct data structure for hartids as it can be higher than NR_CPUs for platforms with sparse or discontguous hartids. Remove all association between hartid mask and struct cpumask. Reviewed-by: Anup Patel (For Linux RISC-V changes) Acked-by: Anup Patel (For KVM RISC-V changes) Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt

RISC-V: Use common riscv_cpuid_to_hartid_mask() for both SMP=y and SMP=n

2022-01-09T20:13:31Z

Use what is currently the SMP=y version of riscv_cpuid_to_hartid_mask() for both SMP=y and SMP=n to fix a build failure with KVM=m and SMP=n due to boot_cpu_hartid not being exported. This also fixes a second bug where the SMP=n version assumes the sole CPU in the system is in the incoming mask, which may not hold true in kvm_riscv_vcpu_sbi_ecall() if the KVM guest VM has multiple vCPUs (on a SMP=n system). Fixes: 1ef46c231df4 ("RISC-V: Implement new SBI v0.2 extensions") Reported-by: Adam Borowski Reviewed-by: Anup Patel Signed-off-by: Sean Christopherson Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt