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2023-10-06riscv: errata: fix T-Head dcache.cva encodingIcenowy Zheng1-2/+2
[ Upstream commit 8eb8fe67e2c84324398f5983c41b4f831d0705b3 ] The dcache.cva encoding shown in the comments are wrong, it's for dcache.cval1 (which is restricted to L1) instead. Fix this in the comment and in the hardcoded instruction. Signed-off-by: Icenowy Zheng <uwu@icenowy.me> Tested-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Drew Fustini <dfustini@baylibre.com> Link: https://lore.kernel.org/r/20230912072410.2481-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23riscv: kexec: Align the kexeced kernel entrySong Shuai1-1/+7
[ Upstream commit 1bfb2b618d52e59a4ef1896b46c4698ad2be66b7 ] The current riscv boot protocol requires 2MB alignment for RV64 and 4MB alignment for RV32. In KEXEC_FILE path, the elf_find_pbase() function should align the kexeced kernel entry according to the requirement, otherwise the kexeced kernel would silently BUG at the setup_vm(). Fixes: 8acea455fafa ("RISC-V: Support for kexec_file on panic") Signed-off-by: Song Shuai <songshuaishuai@tinylab.org> Link: https://lore.kernel.org/r/20230906095817.364390-1-songshuaishuai@tinylab.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30riscv: Fix build errors using binutils2.37 toolchainsMingzheng Xing1-4/+4
commit ef21fa7c198e04f3d3053b1c5b5f2b4b225c3350 upstream. When building the kernel with binutils 2.37 and GCC-11.1.0/GCC-11.2.0, the following error occurs: Assembler messages: Error: cannot find default versions of the ISA extension `zicsr' Error: cannot find default versions of the ISA extension `zifencei' The above error originated from this commit of binutils[0], which has been resolved and backported by GCC-12.1.0[1] and GCC-11.3.0[2]. So fix this by change the GCC version in CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC to GCC-11.3.0. Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=f0bae2552db1dd4f1995608fbf6648fcee4e9e0c [0] Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ca2bbb88f999f4d3cc40e89bc1aba712505dd598 [1] Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 [2] Fixes: ca09f772ccca ("riscv: Handle zicsr/zifencei issue between gcc and binutils") Reported-by: Conor Dooley <conor.dooley@microchip.com> Cc: <stable@vger.kernel.org> Signed-off-by: Mingzheng Xing <xingmingzheng@iscas.ac.cn> Link: https://lore.kernel.org/r/20230824190852.45470-1-xingmingzheng@iscas.ac.cn Closes: https://lore.kernel.org/all/20230823-captive-abdomen-befd942a4a73@wendy/ Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30riscv: Handle zicsr/zifencei issue between gcc and binutilsMingzheng Xing2-12/+24
commit ca09f772cccaeec4cd05a21528c37a260aa2dd2c upstream. Binutils-2.38 and GCC-12.1.0 bumped[0][1] the default ISA spec to the newer 20191213 version which moves some instructions from the I extension to the Zicsr and Zifencei extensions. So if one of the binutils and GCC exceeds that version, we should explicitly specifying Zicsr and Zifencei via -march to cope with the new changes. but this only occurs when binutils >= 2.36 and GCC >= 11.1.0. It's a different story when binutils < 2.36. binutils-2.36 supports the Zifencei extension[2] and splits Zifencei and Zicsr from I[3]. GCC-11.1.0 is particular[4] because it add support Zicsr and Zifencei extension for -march. binutils-2.35 does not support the Zifencei extension, and does not need to specify Zicsr and Zifencei when working with GCC >= 12.1.0. To make our lives easier, let's relax the check to binutils >= 2.36 in CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. For the other two cases, where clang < 17 or GCC < 11.1.0, we will deal with them in CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC. For more information, please refer to: commit 6df2a016c0c8 ("riscv: fix build with binutils 2.38") commit e89c2e815e76 ("riscv: Handle zicsr/zifencei issues between clang and binutils") Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc [0] Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd [1] Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=5a1b31e1e1cee6e9f1c92abff59cdcfff0dddf30 [2] Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=729a53530e86972d1143553a415db34e6e01d5d2 [3] Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=b03be74bad08c382da47e048007a78fa3fb4ef49 [4] Link: https://lore.kernel.org/all/20230308220842.1231003-1-conor@kernel.org Link: https://lore.kernel.org/all/20230223220546.52879-1-conor@kernel.org Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Guo Ren <guoren@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Mingzheng Xing <xingmingzheng@iscas.ac.cn> Link: https://lore.kernel.org/r/20230809165648.21071-1-xingmingzheng@iscas.ac.cn Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-23riscv: uaccess: Return the number of bytes effectively not copiedAlexandre Ghiti1-4/+7
[ Upstream commit 4b05b993900dd3eba0fc83ef5c5ddc7d65d786c6 ] It was reported that the riscv kernel hangs while executing the test in [1]. Indeed, the test hangs when trying to write a buffer to a file. The problem is that the riscv implementation of raw_copy_from_user() does not return the correct number of bytes not written when an exception happens and is fixed up, instead it always returns the initial size to copy, even if some bytes were actually copied. generic_perform_write() pre-faults the user pages and bails out if nothing can be written, otherwise it will access the userspace buffer: here the riscv implementation keeps returning it was not able to copy any byte though the pre-faulting indicates otherwise. So generic_perform_write() keeps retrying to access the user memory and ends up in an infinite loop. Note that before the commit mentioned in [1] that introduced this regression, it worked because generic_perform_write() would bail out if only one byte could not be written. So fix this by returning the number of bytes effectively not written in __asm_copy_[to|from]_user() and __clear_user(), as it is expected. Link: https://lore.kernel.org/linux-riscv/20230309151841.bomov6hq3ybyp42a@debian/ [1] Fixes: ebcbd75e3962 ("riscv: Fix the bug in memory access fixup code") Reported-by: Bo YU <tsu.yubo@gmail.com> Closes: https://lore.kernel.org/linux-riscv/20230309151841.bomov6hq3ybyp42a@debian/#t Reported-by: Aurelien Jarno <aurelien@aurel32.net> Closes: https://lore.kernel.org/linux-riscv/ZNOnCakhwIeue3yr@aurel32.net/ Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Link: https://lore.kernel.org/r/20230811150604.1621784-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-16riscv/kexec: handle R_RISCV_CALL_PLT relocation typeTorsten Duwe1-0/+1
commit d0b4f95a51038becce4bdab4789aa7ce59d4ea6e upstream. R_RISCV_CALL has been deprecated and replaced by R_RISCV_CALL_PLT. See Enum 18-19 in Table 3. Relocation types here: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc It was deprecated in ("Deprecated R_RISCV_CALL, prefer R_RISCV_CALL_PLT"): https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a0dced85018d7a0ec17023c9389cbd70b1dbc1b0 Recent tools (at least GNU binutils-2.40) already use R_RISCV_CALL_PLT. Kernels built with such binutils fail kexec_load_file(2) with: kexec_image: Unknown rela relocation: 19 kexec_image: Error loading purgatory ret=-8 The binary code at the call site remains the same, so tell arch_kexec_apply_relocations_add() to handle _PLT alike. Fixes: 838b3e28488f ("RISC-V: Load purgatory in kexec_file") Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Cc: Li Zhengyu <lizhengyu3@huawei.com> Cc: stable@vger.kernel.org Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/b046b164af8efd33bbdb7d4003273bdf9196a5b0.1690365011.git.petr.tesarik.ext@huawei.com/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-16riscv,mmio: Fix readX()-to-delay() orderingAndrea Parri1-8/+8
commit 4eb2eb1b4c0eb07793c240744843498564a67b83 upstream. Section 2.1 of the Platform Specification [1] states: Unless otherwise specified by a given I/O device, I/O devices are on ordering channel 0 (i.e., they are point-to-point strongly ordered). which is not sufficient to guarantee that a readX() by a hart completes before a subsequent delay() on the same hart (cf. memory-barriers.txt, "Kernel I/O barrier effects"). Set the I(nput) bit in __io_ar() to restore the ordering, align inline comments. [1] https://github.com/riscv/riscv-platform-specs Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20230803042738.5937-1-parri.andrea@gmail.com Fixes: fab957c11efe ("RISC-V: Atomic and Locking Code") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-16riscv/kexec: load initrd high in available memoryTorsten Duwe1-1/+1
commit 49af7a2cd5f678217b8b4f86a29411aebebf3e78 upstream. When initrd is loaded low, the secondary kernel fails like this: INITRD: 0xdc581000+0x00eef000 overlaps in-use memory region This initrd load address corresponds to the _end symbol, but the reservation is aligned on PMD_SIZE, as explained by a comment in setup_bootmem(). It is technically possible to align the initrd load address accordingly, leaving a hole between the end of kernel and the initrd, but it is much simpler to allocate the initrd top-down. Fixes: 838b3e28488f ("RISC-V: Load purgatory in kexec_file") Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Cc: stable@vger.kernel.org Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/67c8eb9eea25717c2c8208d9bfbfaa39e6e2a1c6.1690365011.git.petr.tesarik.ext@huawei.com/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-23riscv: mm: fix truncation warning on RV32Jisheng Zhang1-1/+1
[ Upstream commit b690e266dae2f85f4dfea21fa6a05e3500a51054 ] lkp reports below sparse warning when building for RV32: arch/riscv/mm/init.c:1204:48: sparse: warning: cast truncates bits from constant value (100000000 becomes 0) IMO, the reason we didn't see this truncates bug in real world is "0" means MEMBLOCK_ALLOC_ACCESSIBLE in memblock and there's no RV32 HW with more than 4GB memory. Fix it anyway to make sparse happy. Fixes: decf89f86ecd ("riscv: try to allocate crashkern region from 32bit addressible memory") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202306080034.SLiCiOMn-lkp@intel.com/ Link: https://lore.kernel.org/r/20230709171036.1906-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-23riscv, bpf: Fix inconsistent JIT image generationBjörn Töpel2-9/+16
[ Upstream commit c56fb2aab23505bb7160d06097c8de100b82b851 ] In order to generate the prologue and epilogue, the BPF JIT needs to know which registers that are clobbered. Therefore, the during pre-final passes, the prologue is generated after the body of the program body-prologue-epilogue. Then, in the final pass, a proper prologue-body-epilogue JITted image is generated. This scheme has worked most of the time. However, for some large programs with many jumps, e.g. the test_kmod.sh BPF selftest with hardening enabled (blinding constants), this has shown to be incorrect. For the final pass, when the proper prologue-body-epilogue is generated, the image has not converged. This will lead to that the final image will have incorrect jump offsets. The following is an excerpt from an incorrect image: | ... | 3b8: 00c50663 beq a0,a2,3c4 <.text+0x3c4> | 3bc: 0020e317 auipc t1,0x20e | 3c0: 49630067 jalr zero,1174(t1) # 20e852 <.text+0x20e852> | ... | 20e84c: 8796 c.mv a5,t0 | 20e84e: 6422 c.ldsp s0,8(sp) # Epilogue start | 20e850: 6141 c.addi16sp sp,16 | 20e852: 853e c.mv a0,a5 # Incorrect jump target | 20e854: 8082 c.jr ra The image has shrunk, and the epilogue offset is incorrect in the final pass. Correct the problem by always generating proper prologue-body-epilogue outputs, which means that the first pass will only generate the body to track what registers that are touched. Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230710074131.19596-1-bjorn@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19riscv: move memblock_allow_resize() after linear mapping is readyWoody Zhang1-1/+3
[ Upstream commit 85fadc0d04119c2fe4a20287767ab904c6d21ba1 ] The initial memblock metadata is accessed from kernel image mapping. The regions arrays need to "reallocated" from memblock and accessed through linear mapping to cover more memblock regions. So the resizing should not be allowed until linear mapping is ready. Note that there are memblock allocations when building linear mapping. This patch is similar to 24cc61d8cb5a ("arm64: memblock: don't permit memblock resizing until linear mapping is up"). In following log, many memblock regions are reserved before create_linear_mapping_page_table(). And then it triggered reallocation of memblock.reserved.regions and memcpy the old array in kernel image mapping to the new array in linear mapping which caused a page fault. [ 0.000000] memblock_reserve: [0x00000000bf01f000-0x00000000bf01ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf021000-0x00000000bf021fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf023000-0x00000000bf023fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf025000-0x00000000bf025fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf027000-0x00000000bf027fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf029000-0x00000000bf029fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf02b000-0x00000000bf02bfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf02d000-0x00000000bf02dfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf02f000-0x00000000bf02ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] memblock_reserve: [0x00000000bf030000-0x00000000bf030fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6 [ 0.000000] OF: reserved mem: 0x0000000080000000..0x000000008007ffff (512 KiB) map non-reusable mmode_resv0@80000000 [ 0.000000] memblock_reserve: [0x00000000bf000000-0x00000000bf001fed] paging_init+0x19a/0x5ae [ 0.000000] memblock_phys_alloc_range: 4096 bytes align=0x1000 from=0x0000000000000000 max_addr=0x0000000000000000 alloc_pmd_fixmap+0x14/0x1c [ 0.000000] memblock_reserve: [0x000000017ffff000-0x000000017fffffff] memblock_alloc_range_nid+0xb8/0x128 [ 0.000000] memblock: reserved is doubled to 256 at [0x000000017fffd000-0x000000017fffe7ff] [ 0.000000] Unable to handle kernel paging request at virtual address ff600000ffffd000 [ 0.000000] Oops [#1] [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.4.0-rc1-00011-g99a670b2069c #66 [ 0.000000] Hardware name: riscv-virtio,qemu (DT) [ 0.000000] epc : __memcpy+0x60/0xf8 [ 0.000000] ra : memblock_double_array+0x192/0x248 [ 0.000000] epc : ffffffff8081d214 ra : ffffffff80a3dfc0 sp : ffffffff81403bd0 [ 0.000000] gp : ffffffff814fbb38 tp : ffffffff8140dac0 t0 : 0000000001600000 [ 0.000000] t1 : 0000000000000000 t2 : 000000008f001000 s0 : ffffffff81403c60 [ 0.000000] s1 : ffffffff80c0bc98 a0 : ff600000ffffd000 a1 : ffffffff80c0bcd8 [ 0.000000] a2 : 0000000000000c00 a3 : ffffffff80c0c8d8 a4 : 0000000080000000 [ 0.000000] a5 : 0000000000080000 a6 : 0000000000000000 a7 : 0000000080200000 [ 0.000000] s2 : ff600000ffffd000 s3 : 0000000000002000 s4 : 0000000000000c00 [ 0.000000] s5 : ffffffff80c0bc60 s6 : ffffffff80c0bcc8 s7 : 0000000000000000 [ 0.000000] s8 : ffffffff814fd0a8 s9 : 000000017fffe7ff s10: 0000000000000000 [ 0.000000] s11: 0000000000001000 t3 : 0000000000001000 t4 : 0000000000000000 [ 0.000000] t5 : 000000008f003000 t6 : ff600000ffffd000 [ 0.000000] status: 0000000200000100 badaddr: ff600000ffffd000 cause: 000000000000000f [ 0.000000] [<ffffffff8081d214>] __memcpy+0x60/0xf8 [ 0.000000] [<ffffffff80a3e1a2>] memblock_add_range.isra.14+0x12c/0x162 [ 0.000000] [<ffffffff80a3e36a>] memblock_reserve+0x6e/0x8c [ 0.000000] [<ffffffff80a123fc>] memblock_alloc_range_nid+0xb8/0x128 [ 0.000000] [<ffffffff80a1256a>] memblock_phys_alloc_range+0x5e/0x6a [ 0.000000] [<ffffffff80a04732>] alloc_pmd_fixmap+0x14/0x1c [ 0.000000] [<ffffffff80a0475a>] alloc_p4d_fixmap+0xc/0x14 [ 0.000000] [<ffffffff80a04a36>] create_pgd_mapping+0x98/0x17c [ 0.000000] [<ffffffff80a04e9e>] create_linear_mapping_range.constprop.10+0xe4/0x112 [ 0.000000] [<ffffffff80a05bb8>] paging_init+0x3ec/0x5ae [ 0.000000] [<ffffffff80a03354>] setup_arch+0xb2/0x576 [ 0.000000] [<ffffffff80a00726>] start_kernel+0x72/0x57e [ 0.000000] Code: b303 0285 b383 0305 be03 0385 be83 0405 bf03 0485 (b023) 00ef [ 0.000000] ---[ end trace 0000000000000000 ]--- [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! [ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- Fixes: 671f9a3e2e24 ("RISC-V: Setup initial page tables in two stages") Signed-off-by: Woody Zhang <woodylab@foxmail.com> Tested-by: Song Shuai <songshuaishuai@tinylab.org> Link: https://lore.kernel.org/r/tencent_FBB94CE615C5CCE7701CD39C15CCE0EE9706@qq.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19riscv: uprobes: Restore thread.bad_causeTiezhu Yang1-0/+2
[ Upstream commit 58b1294dd1d65bb62f08dddbf418f954210c2057 ] thread.bad_cause is saved in arch_uprobe_pre_xol(), it should be restored in arch_uprobe_{post,abort}_xol() accordingly, otherwise the save operation is meaningless, this change is similar with x86 and powerpc. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Guo Ren <guoren@kernel.org> Fixes: 74784081aac8 ("riscv: Add uprobes supported") Link: https://lore.kernel.org/r/1682214146-3756-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-01riscv/mm: Convert to using lock_mm_and_find_vma()Ben Hutchings2-18/+14
commit 7267ef7b0b77f4ed23b7b3c87d8eca7bd9c2d007 upstream. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [6.1: Kconfig context] Signed-off-by: Samuel Mendoza-Jonas <samjonas@amazon.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21riscv/purgatory: remove PGO flagsRicardo Ribalda1-0/+5
commit 88ac3bbcf73853880a9b2a65c67e6854390741cc upstream. If profile-guided optimization is enabled, the purgatory ends up with multiple .text sections. This is not supported by kexec and crashes the system. Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-4-b05c520b7296@chromium.org Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory") Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Cc: <stable@vger.kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Philipp Rudo <prudo@redhat.com> Cc: Ross Zwisler <zwisler@google.com> Cc: Simon Horman <horms@kernel.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Rix <trix@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14riscv: fix kprobe __user string arg print fault issueRuan Jinjie1-0/+1
[ Upstream commit 99a670b2069c725a7b50318aa681d9cae8f89325 ] On riscv qemu platform, when add kprobe event on do_sys_open() to show filename string arg, it just print fault as follow: echo 'p:myprobe do_sys_open dfd=$arg1 filename=+0($arg2):string flags=$arg3 mode=$arg4' > kprobe_events bash-166 [000] ...1. 360.195367: myprobe: (do_sys_open+0x0/0x84) dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6 bash-166 [000] ...1. 360.219369: myprobe: (do_sys_open+0x0/0x84) dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6 bash-191 [000] ...1. 360.378827: myprobe: (do_sys_open+0x0/0x84) dfd=0xffffffffffffff9c filename=(fault) flags=0x98800 mode=0x0 As riscv do not select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE, the +0($arg2) addr is processed as a kernel address though it is a userspace address, cause the above filename=(fault) print. So select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE to avoid the issue, after that the kprobe trace is ok as below: bash-166 [000] ...1. 96.767641: myprobe: (do_sys_open+0x0/0x84) dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6 bash-166 [000] ...1. 96.793751: myprobe: (do_sys_open+0x0/0x84) dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6 bash-177 [000] ...1. 96.962354: myprobe: (do_sys_open+0x0/0x84) dfd=0xffffffffffffff9c filename="/sys/kernel/debug/tracing/events/kprobes/" flags=0x98800 mode=0x0 Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com> Acked-by: Björn Töpel <bjorn@rivosinc.com> Fixes: 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work") Link: https://lore.kernel.org/r/20230504072910.3742842-1-ruanjinjie@huawei.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-14riscv: mm: Ensure prot of VM_WRITE and VM_EXEC must be readableHsieh-Tseng Shen2-3/+2
[ Upstream commit 6569fc12e442ea973d96db39e542aa19a7bc3a79 ] Commit 8aeb7b17f04e ("RISC-V: Make mmap() with PROT_WRITE imply PROT_READ") allows riscv to use mmap with PROT_WRITE only, and meanwhile mmap with w+x is also permitted. However, when userspace tries to access this page with PROT_WRITE|PROT_EXEC, which causes infinite loop at load page fault as well as it triggers soft lockup. According to riscv privileged spec, "Writable pages must also be marked readable". The fix to drop the `PAGE_COPY_READ_EXEC` and then `PAGE_COPY_EXEC` would be just used instead. This aligns the other arches (i.e arm64) for protection_map. Fixes: 8aeb7b17f04e ("RISC-V: Make mmap() with PROT_WRITE imply PROT_READ") Signed-off-by: Hsieh-Tseng Shen <woodrow.shen@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230425102828.1616812-1-woodrow.shen@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-09riscv: perf: Fix callchain parse error with kernel tracepoint eventsIsm Hong1-0/+7
commit 9a7e8ec0d4cc64870ea449b4fce5779b77496cbb upstream. For RISC-V, when tracing with tracepoint events, the IP and status are set to 0, preventing the perf code parsing the callchain and resolving the symbols correctly. ./ply 'tracepoint:kmem/kmem_cache_alloc { @[stack]=count(); }' @: { <STACKID4294967282> }: 1 The fix is to implement perf_arch_fetch_caller_regs for riscv, which fills several necessary registers used for callchain unwinding, including epc, sp, s0 and status. It's similar to commit b3eac0265bf6 ("arm: perf: Fix callchain parse error with kernel tracepoint events") and commit 5b09a094f2fb ("arm64: perf: Fix callchain parse error with kernel tracepoint events"). With this patch, callchain can be parsed correctly as: ./ply 'tracepoint:kmem/kmem_cache_alloc { @[stack]=count(); }' @: { __traceiter_kmem_cache_alloc+68 __traceiter_kmem_cache_alloc+68 kmem_cache_alloc+354 __sigqueue_alloc+94 __send_signal_locked+646 send_signal_locked+154 do_send_sig_info+84 __kill_pgrp_info+130 kill_pgrp+60 isig+150 n_tty_receive_signal_char+36 n_tty_receive_buf_standard+2214 n_tty_receive_buf_common+280 n_tty_receive_buf2+26 tty_ldisc_receive_buf+34 tty_port_default_receive_buf+62 flush_to_ldisc+158 process_one_work+458 worker_thread+138 kthread+178 riscv_cpufeature_patch_func+832 }: 1 Signed-off-by: Ism Hong <ism.hong@gmail.com> Link: https://lore.kernel.org/r/20230601095355.1168910-1-ism.hong@gmail.com Fixes: 178e9fc47aae ("perf: riscv: preliminary RISC-V support") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-09riscv: Fix unused variable warning when BUILTIN_DTB is setAlexandre Ghiti1-1/+1
[ Upstream commit 33d418da6f476b15e4510e0a590062583f63cd36 ] commit ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region") wrongly moved the #ifndef CONFIG_BUILTIN_DTB surrounding the pa variable definition in create_fdt_early_page_table(), so move it back to its right place to quiet the following warning: ../arch/riscv/mm/init.c: In function ‘create_fdt_early_page_table’: ../arch/riscv/mm/init.c:925:12: warning: unused variable ‘pa’ [-Wunused-variable] 925 | uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1); Fixes: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230519131311.391960-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-24rethook, fprobe: do not trace rethook related functionsZe Gao1-0/+2
commit 571a2a50a8fc546145ffd3bf673547e9fe128ed2 upstream. These functions are already marked as NOKPROBE to prevent recursion and we have the same reason to blacklist them if rethook is used with fprobe, since they are beyond the recursion-free region ftrace can guard. Link: https://lore.kernel.org/all/20230517034510.15639-5-zegao@tencent.com/ Fixes: f3a112c0c40d ("x86,rethook,kprobes: Replace kretprobe with rethook on x86") Signed-off-by: Ze Gao <zegao@tencent.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17RISC-V: fix taking the text_mutex twice during sifive errata patchingConor Dooley1-1/+1
commit bf89b7ee52af5a5944fa3539e86089f72475055b upstream. Chris pointed out that some bonehead, *cough* me *cough*, added two mutex_locks() to the SiFive errata patching. The second was meant to have been a mutex_unlock(). This results in errors such as Unable to handle kernel NULL pointer dereference at virtual address 0000000000000030 Oops [#1] Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.2.0-rc1-starlight-00079-g9493e6f3ce02 #229 Hardware name: BeagleV Starlight Beta (DT) epc : __schedule+0x42/0x500 ra : schedule+0x46/0xce epc : ffffffff8065957c ra : ffffffff80659a80 sp : ffffffff81203c80 gp : ffffffff812d50a0 tp : ffffffff8120db40 t0 : ffffffff81203d68 t1 : 0000000000000001 t2 : 4c45203a76637369 s0 : ffffffff81203cf0 s1 : ffffffff8120db40 a0 : 0000000000000000 a1 : ffffffff81213958 a2 : ffffffff81213958 a3 : 0000000000000000 a4 : 0000000000000000 a5 : ffffffff80a1bd00 a6 : 0000000000000000 a7 : 0000000052464e43 s2 : ffffffff8120db41 s3 : ffffffff80a1ad00 s4 : 0000000000000000 s5 : 0000000000000002 s6 : ffffffff81213938 s7 : 0000000000000000 s8 : 0000000000000000 s9 : 0000000000000001 s10: ffffffff812d7204 s11: ffffffff80d3c920 t3 : 0000000000000001 t4 : ffffffff812e6dd7 t5 : ffffffff812e6dd8 t6 : ffffffff81203bb8 status: 0000000200000100 badaddr: 0000000000000030 cause: 000000000000000d [<ffffffff80659a80>] schedule+0x46/0xce [<ffffffff80659dce>] schedule_preempt_disabled+0x16/0x28 [<ffffffff8065ae0c>] __mutex_lock.constprop.0+0x3fe/0x652 [<ffffffff8065b138>] __mutex_lock_slowpath+0xe/0x16 [<ffffffff8065b182>] mutex_lock+0x42/0x4c [<ffffffff8000ad94>] sifive_errata_patch_func+0xf6/0x18c [<ffffffff80002b92>] _apply_alternatives+0x74/0x76 [<ffffffff80802ee8>] apply_boot_alternatives+0x3c/0xfa [<ffffffff80803cb0>] setup_arch+0x60c/0x640 [<ffffffff80800926>] start_kernel+0x8e/0x99c ---[ end trace 0000000000000000 ]--- Reported-by: Chris Hofstaedtler <zeha@debian.org> Fixes: 9493e6f3ce02 ("RISC-V: take text_mutex during alternative patching") Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20230302174154.970746-1-conor@kernel.org [Palmer: pick up Geert's bug report from the thread] Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17RISC-V: take text_mutex during alternative patchingConor Dooley3-3/+14
commit 9493e6f3ce02f44c21aa19f3cbf3b9aa05479d06 upstream. Guenter reported a splat during boot, that Samuel pointed out was the lockdep assertion failing in patch_insn_write(): WARNING: CPU: 0 PID: 0 at arch/riscv/kernel/patch.c:63 patch_insn_write+0x222/0x2f6 epc : patch_insn_write+0x222/0x2f6 ra : patch_insn_write+0x21e/0x2f6 epc : ffffffff800068c6 ra : ffffffff800068c2 sp : ffffffff81803df0 gp : ffffffff81a1ab78 tp : ffffffff81814f80 t0 : ffffffffffffe000 t1 : 0000000000000001 t2 : 4c45203a76637369 s0 : ffffffff81803e40 s1 : 0000000000000004 a0 : 0000000000000000 a1 : ffffffffffffffff a2 : 0000000000000004 a3 : 0000000000000000 a4 : 0000000000000001 a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000052464e43 s2 : ffffffff80b4889c s3 : 000000000000082c s4 : ffffffff80b48828 s5 : 0000000000000828 s6 : ffffffff8131a0a0 s7 : 0000000000000fff s8 : 0000000008000200 s9 : ffffffff8131a520 s10: 0000000000000018 s11: 000000000000000b t3 : 0000000000000001 t4 : 000000000000000d t5 : ffffffffd8180000 t6 : ffffffff81803bc8 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [<ffffffff800068c6>] patch_insn_write+0x222/0x2f6 [<ffffffff80006a36>] patch_text_nosync+0xc/0x2a [<ffffffff80003b86>] riscv_cpufeature_patch_func+0x52/0x98 [<ffffffff80003348>] _apply_alternatives+0x46/0x86 [<ffffffff80c02d36>] apply_boot_alternatives+0x3c/0xfa [<ffffffff80c03ad8>] setup_arch+0x584/0x5b8 [<ffffffff80c0075a>] start_kernel+0xa2/0x8f8 This issue was exposed by 702e64550b12 ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()"), as it is the patching in has_fpu() that triggers the splats in Guenter's report. Take the text_mutex before doing any code patching to satisfy lockdep. Fixes: ff689fd21cb1 ("riscv: add RISC-V Svpbmt extension support") Fixes: a35707c3d850 ("riscv: add memory-type errata for T-Head") Fixes: 1a0e5dbd3723 ("riscv: sifive: Add SiFive alternative ports") Reported-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/all/20230212154333.GA3760469@roeck-us.net/ Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Samuel Holland <samuel@sholland.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230212194735.491785-1-conor@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17riscv: compat_syscall_table: Fixup compile warningGuo Ren1-0/+1
[ Upstream commit f9c4bbddece7eff1155c70d48e3c9c2a01b9d778 ] ../arch/riscv/kernel/compat_syscall_table.c:12:41: warning: initialized field overwritten [-Woverride-init] 12 | #define __SYSCALL(nr, call) [nr] = (call), | ^ ../include/uapi/asm-generic/unistd.h:567:1: note: in expansion of macro '__SYSCALL' 567 | __SYSCALL(__NR_semget, sys_semget) Fixes: 59c10c52f573 ("riscv: compat: syscall: Add compat_sys_call_table implementation") Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reported-by: kernel test robot <lkp@intel.com> Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Signed-off-by: Drew Fustini <dfustini@baylibre.com> Link: https://lore.kernel.org/r/20230501223353.2833899-1-dfustini@baylibre.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17RISC-V: mm: Enable huge page support to kernel_page_present() functionSia Jee Heng1-0/+8
[ Upstream commit a15c90b67a662c75f469822a7f95c7aaa049e28f ] Currently kernel_page_present() function doesn't support huge page detection causes the function to mistakenly return false to the hibernation core. Add huge page detection to the function to solve the problem. Fixes: 9e953cda5cdf ("riscv: Introduce huge page support for 32/64bit kernel") Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com> Reviewed-by: Ley Foon Tan <leyfoon.tan@starfivetech.com> Reviewed-by: Mason Huo <mason.huo@starfivetech.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230330064321.1008373-4-jeeheng.sia@starfivetech.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11riscv: Fix ptdump when KASAN is enabledAlexandre Ghiti1-12/+12
[ Upstream commit ecd7ebaf0b5a094a6180b299a5635c0eea42be4b ] The KASAN shadow region was moved next to the kernel mapping but the ptdump code was not updated and it appears to break the dump of the kernel page table, so fix this by moving the KASAN shadow region in ptdump. Fixes: f7ae02333d13 ("riscv: Move KASAN mapping next to the kernel mapping") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230203075232.274282-6-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11RISC-V: Align SBI probe implementation with specAndrew Jones4-12/+11
commit 41cad8284d5e6bf1d49d3c10a6b52ee1ae866a20 upstream. sbi_probe_extension() is specified with "Returns 0 if the given SBI extension ID (EID) is not available, or 1 if it is available unless defined as any other non-zero value by the implementation." Additionally, sbiret.value is a long. Fix the implementation to ensure any nonzero long value is considered a success, rather than only positive int values. Fixes: b9dcd9e41587 ("RISC-V: Add basic support for SBI v0.2") Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230427163626.101042-1-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-11riscv: mm: remove redundant parameter of create_fdt_early_page_tableSong Shuai1-4/+2
commit e4ef93edd4e0b022529303db1915766ff9de450e upstream. create_fdt_early_page_table() explicitly uses early_pg_dir for 32-bit fdt mapping and the pgdir parameter is redundant here. So remove it and its caller. Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Song Shuai <suagrfillet@gmail.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Fixes: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230426100009.685435-1-suagrfillet@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-11KVM: RISC-V: Retry fault if vma_lookup() results become invalidDavid Matlack1-9/+16
commit 2ed90cb0938a45b12eb947af062d12c7af0067b3 upstream. Read mmu_invalidate_seq before dropping the mmap_lock so that KVM can detect if the results of vma_lookup() (e.g. vma_shift) become stale before it acquires kvm->mmu_lock. This fixes a theoretical bug where a VMA could be changed by userspace after vma_lookup() and before KVM reads the mmu_invalidate_seq, causing KVM to install page table entries based on a (possibly) no-longer-valid vma_shift. Re-order the MMU cache top-up to earlier in user_mem_abort() so that it is not done after KVM has read mmu_invalidate_seq (i.e. so as to avoid inducing spurious fault retries). It's unlikely that any sane userspace currently modifies VMAs in such a way as to trigger this race. And even with directed testing I was unable to reproduce it. But a sufficiently motivated host userspace might be able to exploit this race. Note KVM/ARM had the same bug and was fixed in a separate, near identical patch (see Link). Link: https://lore.kernel.org/kvm/20230313235454.2964067-1-dmatlack@google.com/ Fixes: 9955371cc014 ("RISC-V: KVM: Implement MMU notifiers") Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Tested-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-01riscv: No need to relocate the dtb as it lies in the fixmap regionAlexandre Ghiti1-19/+2
commit 1b50f956c8fe9082bdee4a9cfd798149c52f7043 upstream. We used to access the dtb via its linear mapping address but now that the dtb early mapping was moved in the fixmap region, we can keep using this address since it is present in swapper_pg_dir, and remove the dtb relocation. Note that the relocation was wrong anyway since early_memremap() is restricted to 256K whereas the maximum fdt size is 2MB. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230329081932.79831-4-alexghiti@rivosinc.com Cc: stable@vger.kernel.org # 6.1.x Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-01riscv: Do not set initial_boot_params to the linear address of the dtbAlexandre Ghiti1-4/+1
commit f1581626071c8e37c58c5e8f0b4126b17172a211 upstream. early_init_dt_verify() is already called in parse_dtb() and since the dtb address does not change anymore (it is now in the fixmap region), no need to reset initial_boot_params by calling early_init_dt_verify() again. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230329081932.79831-3-alexghiti@rivosinc.com Cc: stable@vger.kernel.org # 6.1.x Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-01riscv: Move early dtb mapping into the fixmap regionAlexandre Ghiti4-30/+48
commit ef69d2559fe91f23d27a3d6fd640b5641787d22e upstream. riscv establishes 2 virtual mappings: - early_pg_dir maps the kernel which allows to discover the system memory - swapper_pg_dir installs the final mapping (linear mapping included) We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this mapping was not carried over in swapper_pg_dir. It happens that early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is setup otherwise we could allocate reserved memory defined in the dtb. And this function initializes reserved_mem variable with addresses that lie in the early_pg_dir dtb mapping: when those addresses are reused with swapper_pg_dir, this mapping does not exist and then we trap. The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is set up otherwise we could allocate in reserved memory defined in the dtb. So move the dtb mapping in the fixmap region which is established in early_pg_dir and handed over to swapper_pg_dir. This patch had to be backported because: - the documentation for sv57 is not present here (as sv48/57 are not present) Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob") Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap") Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup") Reported-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/ Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc.com Cc: stable@vger.kernel.org # 6.1.x Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-26purgatory: fix disabling debug infoAlyssa Ross1-3/+1
commit d83806c4c0cccc0d6d3c3581a11983a9c186a138 upstream. Since 32ef9e5054ec, -Wa,-gdwarf-2 is no longer used in KBUILD_AFLAGS. Instead, it includes -g, the appropriate -gdwarf-* flag, and also the -Wa versions of both of those if building with Clang and GNU as. As a result, debug info was being generated for the purgatory objects, even though the intention was that it not be. Fixes: 32ef9e5054ec ("Makefile.debug: re-enable debug info for .S files") Signed-off-by: Alyssa Ross <hi@alyssa.is> Cc: stable@vger.kernel.org Acked-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20riscv: add icache flush for nommu sigreturn trampolineMathis Salmen1-1/+8
commit 8d736482749f6d350892ef83a7a11d43cd49981e upstream. In a NOMMU kernel, sigreturn trampolines are generated on the user stack by setup_rt_frame. Currently, these trampolines are not instruction fenced, thus their visibility to ifetch is not guaranteed. This patch adds a flush_icache_range in setup_rt_frame to fix this problem. Signed-off-by: Mathis Salmen <mathis.salmen@matsal.de> Fixes: 6bd33e1ece52 ("riscv: add nommu support") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230406101130.82304-1-mathis.salmen@matsal.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-06riscv/kvm: Fix VM hang in case of timer delta being zero.Rajnesh Kanwal1-4/+2
[ Upstream commit 6eff38048944cadc3cddcf117acfa5199ec32490 ] In case when VCPU is blocked due to WFI, we schedule the timer from `kvm_riscv_vcpu_timer_blocking()` to keep timer interrupt ticking. But in case when delta_ns comes to be zero, we never schedule the timer and VCPU keeps sleeping indefinitely until any activity is done with VM console. This is easily reproduce-able using kvmtool. ./lkvm-static run -c1 --console virtio -p "earlycon root=/dev/vda" \ -k ./Image -d rootfs.ext4 Also, just add a print in kvm_riscv_vcpu_vstimer_expired() to check the interrupt delivery and run `top` or similar auto-upating cmd from guest. Within sometime one can notice that print from timer expiry routine stops and the `top` cmd output will stop updating. This change fixes this by making sure we schedule the timer even with delta_ns being zero to bring the VCPU out of sleep immediately. Fixes: 8f5cb44b1bae ("RISC-V: KVM: Support sstc extension") Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-06riscv: ftrace: Fixup panic by disabling preemptionAndy Chiu1-1/+1
[ Upstream commit 8547649981e6631328cd64f583667501ae385531 ] In RISCV, we must use an AUIPC + JALR pair to encode an immediate, forming a jump that jumps to an address over 4K. This may cause errors if we want to enable kernel preemption and remove dependency from patching code with stop_machine(). For example, if a task was switched out on auipc. And, if we changed the ftrace function before it was switched back, then it would jump to an address that has updated 11:0 bits mixing with previous XLEN:12 part. p: patched area performed by dynamic ftrace ftrace_prologue: p| REG_S ra, -SZREG(sp) p| auipc ra, 0x? ------------> preempted ... change ftrace function ... p| jalr -?(ra) <------------- switched back p| REG_L ra, -SZREG(sp) func: xxx ret Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT") Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230112090603.1295340-2-guoren@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30riscv: Handle zicsr/zifencei issues between clang and binutilsNathan Chancellor2-4/+28
commit e89c2e815e76471cb507bd95728bf26da7976430 upstream. There are two related issues that appear in certain combinations with clang and GNU binutils. The first occurs when a version of clang that supports zicsr or zifencei via '-march=' [1] (i.e, >= 17.x) is used in combination with a version of GNU binutils that do not recognize zicsr and zifencei in the '-march=' value (i.e., < 2.36): riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicsr2p0_zifencei2p0: Invalid or unknown z ISA extension: 'zifencei' riscv64-linux-gnu-ld: failed to merge target specific data of file fs/efivarfs/file.o riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicsr2p0_zifencei2p0: Invalid or unknown z ISA extension: 'zifencei' riscv64-linux-gnu-ld: failed to merge target specific data of file fs/efivarfs/super.o The second occurs when a version of clang that does not support zicsr or zifencei via '-march=' (i.e., <= 16.x) is used in combination with a version of GNU as that defaults to a newer ISA base spec, which requires specifying zicsr and zifencei in the '-march=' value explicitly (i.e, >= 2.38): ../arch/riscv/kernel/kexec_relocate.S: Assembler messages: ../arch/riscv/kernel/kexec_relocate.S:147: Error: unrecognized opcode `fence.i', extension `zifencei' required clang-12: error: assembler command failed with exit code 1 (use -v to see invocation) This is the same issue addressed by commit 6df2a016c0c8 ("riscv: fix build with binutils 2.38") (see [2] for additional information) but older versions of clang miss out on it because the cc-option check fails: clang-12: error: invalid arch name 'rv64imac_zicsr_zifencei', unsupported standard user-level extension 'zicsr' clang-12: error: invalid arch name 'rv64imac_zicsr_zifencei', unsupported standard user-level extension 'zicsr' To resolve the first issue, only attempt to add zicsr and zifencei to the march string when using the GNU assembler 2.38 or newer, which is when the default ISA spec was updated, requiring these extensions to be specified explicitly. LLVM implements an older version of the base specification for all currently released versions, so these instructions are available as part of the 'i' extension. If LLVM's implementation is updated in the future, a CONFIG_AS_IS_LLVM condition can be added to CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. To resolve the second issue, use version 2.2 of the base ISA spec when using an older version of clang that does not support zicsr or zifencei via '-march=', as that is the spec version most compatible with the one clang/LLVM implements and avoids the need to specify zicsr and zifencei explicitly due to still being a part of 'i'. [1]: https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 [2]: https://lore.kernel.org/ZAxT7T9Xy1Fo3d5W@aurel32.net/ Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1808 Co-developed-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230313-riscv-zicsr-zifencei-fiasco-v1-1-dd1b7840a551@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-30riscv: mm: Fix incorrect ASID argument when flushing TLBDylan Jhong3-2/+4
commit 9a801afd3eb95e1a89aba17321062df06fb49d98 upstream. Currently, we pass the CONTEXTID instead of the ASID to the TLB flush function. We should only take the ASID field to prevent from touching the reserved bit field. Fixes: 3f1e782998cd ("riscv: add ASID-based tlbflushing methods") Signed-off-by: Dylan Jhong <dylan@andestech.com> Reviewed-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Link: https://lore.kernel.org/r/20230313034906.2401730-1-dylan@andestech.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-30riscv: Bump COMMAND_LINE_SIZE value to 1024Alexandre Ghiti1-0/+8
[ Upstream commit 61fc1ee8be26bc192d691932b0a67eabee45d12f ] Increase COMMAND_LINE_SIZE as the current default value is too low for syzbot kernel command line. There has been considerable discussion on this patch that has led to a larger patch set removing COMMAND_LINE_SIZE from the uapi headers on all ports. That's not quite done yet, but it's gotten far enough we're confident this is not a uABI change so this is safe. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Link: https://lore.kernel.org/r/20210316193420.904-1-alex@ghiti.fr [Palmer: it's not uabi] Link: https://lore.kernel.org/linux-riscv/874b8076-b0d1-4aaa-bcd8-05d523060152@app.fastmail.com/#t Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-22riscv: asid: Fixup stale TLB entry cause application crashGuo Ren1-10/+20
commit 82dd33fde0268cc622d3d1ac64971f3f61634142 upstream. After use_asid_allocator is enabled, the userspace application will crash by stale TLB entries. Because only using cpumask_clear_cpu without local_flush_tlb_all couldn't guarantee CPU's TLB entries were fresh. Then set_mm_asid would cause the user space application to get a stale value by stale TLB entry, but set_mm_noasid is okay. Here is the symptom of the bug: unhandled signal 11 code 0x1 (coredump) 0x0000003fd6d22524 <+4>: auipc s0,0x70 0x0000003fd6d22528 <+8>: ld s0,-148(s0) # 0x3fd6d92490 => 0x0000003fd6d2252c <+12>: ld a5,0(s0) (gdb) i r s0 s0 0x8082ed1cc3198b21 0x8082ed1cc3198b21 (gdb) x /2x 0x3fd6d92490 0x3fd6d92490: 0xd80ac8a8 0x0000003f The core dump file shows that register s0 is wrong, but the value in memory is correct. Because 'ld s0, -148(s0)' used a stale mapping entry in TLB and got a wrong result from an incorrect physical address. When the task ran on CPU0, which loaded/speculative-loaded the value of address(0x3fd6d92490), then the first version of the mapping entry was PTWed into CPU0's TLB. When the task switched from CPU0 to CPU1 (No local_tlb_flush_all here by asid), it happened to write a value on the address (0x3fd6d92490). It caused do_page_fault -> wp_page_copy -> ptep_clear_flush -> ptep_get_and_clear & flush_tlb_page. The flush_tlb_page used mm_cpumask(mm) to determine which CPUs need TLB flush, but CPU0 had cleared the CPU0's mm_cpumask in the previous switch_mm. So we only flushed the CPU1 TLB and set the second version mapping of the PTE. When the task switched from CPU1 to CPU0 again, CPU0 still used a stale TLB mapping entry which contained a wrong target physical address. It raised a bug when the task happened to read that value. CPU0 CPU1 - switch 'task' in - read addr (Fill stale mapping entry into TLB) - switch 'task' out (no tlb_flush) - switch 'task' in (no tlb_flush) - write addr cause pagefault do_page_fault() (change to new addr mapping) wp_page_copy() ptep_clear_flush() ptep_get_and_clear() & flush_tlb_page() write new value into addr - switch 'task' out (no tlb_flush) - switch 'task' in (no tlb_flush) - read addr again (Use stale mapping entry in TLB) get wrong value from old phyical addr, BUG! The solution is to keep all CPUs' footmarks of cpumask(mm) in switch_mm, which could guarantee to invalidate all stale TLB entries during TLB flush. Fixes: 65d4b9c53017 ("RISC-V: Implement ASID allocator") Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Tested-by: Zong Li <zong.li@sifive.com> Tested-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Cc: Anup Patel <apatel@ventanamicro.com> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: stable@vger.kernel.org Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230226150137.1919750-3-geomatsi@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22Revert "riscv: mm: notify remote harts about mmu cache updates"Sergey Matyukevich4-41/+17
commit e921050022f1f12d5029d1487a7dfc46cde15523 upstream. This reverts the remaining bits of commit 4bd1d80efb5a ("riscv: mm: notify remote harts harts about mmu cache updates"). According to bug reports, suggested approach to fix stale TLB entries is not sufficient. It needs to be replaced by a more robust solution. Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates") Reported-by: Zong Li <zong.li@sifive.com> Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Cc: stable@vger.kernel.org Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230226150137.1919750-2-geomatsi@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17RISC-V: Don't check text_mutex during stop_machineConor Dooley4-6/+39
[ Upstream commit 2a8db5ec4a28a0fce822d10224db9471a44b6925 ] We're currently using stop_machine() to update ftrace & kprobes, which means that the thread that takes text_mutex during may not be the same as the thread that eventually patches the code. This isn't actually a race because the lock is still held (preventing any other concurrent accesses) and there is only one thread running during stop_machine(), but it does trigger a lockdep failure. This patch just elides the lockdep check during stop_machine. Fixes: c15ac4fd60d5 ("riscv/ftrace: Add dynamic function tracer support") Suggested-by: Steven Rostedt <rostedt@goodmis.org> Reported-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230303143754.4005217-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack modeAlexandre Ghiti1-1/+1
[ Upstream commit 76950340cf03b149412fe0d5f0810e52ac1df8cb ] When CONFIG_FRAME_POINTER is unset, the stack unwinding function walk_stackframe randomly reads the stack and then, when KASAN is enabled, it can lead to the following backtrace: [ 0.000000] ================================================================== [ 0.000000] BUG: KASAN: stack-out-of-bounds in walk_stackframe+0xa6/0x11a [ 0.000000] Read of size 8 at addr ffffffff81807c40 by task swapper/0 [ 0.000000] [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.2.0-12919-g24203e6db61f #43 [ 0.000000] Hardware name: riscv-virtio,qemu (DT) [ 0.000000] Call Trace: [ 0.000000] [<ffffffff80007ba8>] walk_stackframe+0x0/0x11a [ 0.000000] [<ffffffff80099ecc>] init_param_lock+0x26/0x2a [ 0.000000] [<ffffffff80007c4a>] walk_stackframe+0xa2/0x11a [ 0.000000] [<ffffffff80c49c80>] dump_stack_lvl+0x22/0x36 [ 0.000000] [<ffffffff80c3783e>] print_report+0x198/0x4a8 [ 0.000000] [<ffffffff80099ecc>] init_param_lock+0x26/0x2a [ 0.000000] [<ffffffff80007c4a>] walk_stackframe+0xa2/0x11a [ 0.000000] [<ffffffff8015f68a>] kasan_report+0x9a/0xc8 [ 0.000000] [<ffffffff80007c4a>] walk_stackframe+0xa2/0x11a [ 0.000000] [<ffffffff80007c4a>] walk_stackframe+0xa2/0x11a [ 0.000000] [<ffffffff8006e99c>] desc_make_final+0x80/0x84 [ 0.000000] [<ffffffff8009a04e>] stack_trace_save+0x88/0xa6 [ 0.000000] [<ffffffff80099fc2>] filter_irq_stacks+0x72/0x76 [ 0.000000] [<ffffffff8006b95e>] devkmsg_read+0x32a/0x32e [ 0.000000] [<ffffffff8015ec16>] kasan_save_stack+0x28/0x52 [ 0.000000] [<ffffffff8006e998>] desc_make_final+0x7c/0x84 [ 0.000000] [<ffffffff8009a04a>] stack_trace_save+0x84/0xa6 [ 0.000000] [<ffffffff8015ec52>] kasan_set_track+0x12/0x20 [ 0.000000] [<ffffffff8015f22e>] __kasan_slab_alloc+0x58/0x5e [ 0.000000] [<ffffffff8015e7ea>] __kmem_cache_create+0x21e/0x39a [ 0.000000] [<ffffffff80e133ac>] create_boot_cache+0x70/0x9c [ 0.000000] [<ffffffff80e17ab2>] kmem_cache_init+0x6c/0x11e [ 0.000000] [<ffffffff80e00fd6>] mm_init+0xd8/0xfe [ 0.000000] [<ffffffff80e011d8>] start_kernel+0x190/0x3ca [ 0.000000] [ 0.000000] The buggy address belongs to stack of task swapper/0 [ 0.000000] and is located at offset 0 in frame: [ 0.000000] stack_trace_save+0x0/0xa6 [ 0.000000] [ 0.000000] This frame has 1 object: [ 0.000000] [32, 56) 'c' [ 0.000000] [ 0.000000] The buggy address belongs to the physical page: [ 0.000000] page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x81a07 [ 0.000000] flags: 0x1000(reserved|zone=0) [ 0.000000] raw: 0000000000001000 ff600003f1e3d150 ff600003f1e3d150 0000000000000000 [ 0.000000] raw: 0000000000000000 0000000000000000 00000001ffffffff [ 0.000000] page dumped because: kasan: bad access detected [ 0.000000] [ 0.000000] Memory state around the buggy address: [ 0.000000] ffffffff81807b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 0.000000] ffffffff81807b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 0.000000] >ffffffff81807c00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 f3 [ 0.000000] ^ [ 0.000000] ffffffff81807c80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 [ 0.000000] ffffffff81807d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 0.000000] ================================================================== Fix that by using READ_ONCE_NOCHECK when reading the stack in imprecise mode. Fixes: 5d8544e2d007 ("RISC-V: Generic library routines and assembly") Reported-by: Chathura Rajapaksha <chathura.abeyrathne.lk@gmail.com> Link: https://lore.kernel.org/all/CAD7mqryDQCYyJ1gAmtMm8SASMWAQ4i103ptTb0f6Oda=tPY2=A@mail.gmail.com/ Suggested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230308091639.602024-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17riscv: Add header include guards to insn.hLiao Chang1-0/+5
[ Upstream commit 8ac6e619d9d51b3eb5bae817db8aa94e780a0db4 ] Add header include guards to insn.h to prevent repeating declaration of any identifiers in insn.h. Fixes: edde5584c7ab ("riscv: Add SW single-step support for KDB") Signed-off-by: Liao Chang <liaochang1@huawei.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Fixes: c9c1af3f186a ("RISC-V: rename parse_asm.h to insn.h") Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230129094242.282620-1-liaochang1@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17RISC-V: Stop emitting attributesPalmer Dabbelt2-0/+11
commit e18048da9bc3f87acef4eb67a11b4fc55fe15424 upstream. The RISC-V ELF attributes don't contain any useful information. New toolchains ignore them, but they frequently trip up various older/mixed toolchains. So just turn them off. Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230223224605.6995-1-palmer@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10riscv: ftrace: Reduce the detour code size to halfGuo Ren4-86/+75
commit 6724a76cff85ee271bbbff42ac527e4643b2ec52 upstream. Use a temporary register to reduce the size of detour code from 16 bytes to 8 bytes. The previous implementation is from 'commit afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")'. Before the patch: <func_prolog>: 0: REG_S ra, -SZREG(sp) 4: auipc ra, ? 8: jalr ?(ra) 12: REG_L ra, -SZREG(sp) (func_boddy) After the patch: <func_prolog>: 0: auipc t0, ? 4: jalr t0, ?(t0) (func_boddy) This patch not just reduces the size of detour code, but also fixes an important issue: An Ftrace callback registered with FTRACE_OPS_FL_IPMODIFY flag can actually change the instruction pointer, e.g. to "replace" the given kernel function with a new one, which is needed for livepatching, etc. In this case, the trampoline (ftrace_regs_caller) would not return to <func_prolog+12> but would rather jump to the new function. So, "REG_L ra, -SZREG(sp)" would not run and the original return address would not be restored. The kernel is likely to hang or crash as a result. This can be easily demonstrated if one tries to "replace", say, cmdline_proc_show() with a new function with the same signature using instruction_pointer_set(&fregs->regs, new_func_addr) in the Ftrace callback. Link: https://lore.kernel.org/linux-riscv/20221122075440.1165172-1-suagrfillet@gmail.com/ Link: https://lore.kernel.org/linux-riscv/d7d5730b-ebef-68e5-5046-e763e1ee6164@yadro.com/ Co-developed-by: Song Shuai <suagrfillet@gmail.com> Signed-off-by: Song Shuai <suagrfillet@gmail.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Evgenii Shatokhin <e.shatokhin@yadro.com> Reviewed-by: Evgenii Shatokhin <e.shatokhin@yadro.com> Link: https://lore.kernel.org/r/20230112090603.1295340-4-guoren@kernel.org Cc: stable@vger.kernel.org Fixes: 10626c32e382 ("riscv/ftrace: Add basic support") Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10riscv: ftrace: Remove wasted nops for !RISCV_ISA_CGuo Ren1-0/+4
commit 409c8fb20c66df7150e592747412438c04aeb11f upstream. When CONFIG_RISCV_ISA_C=n, -fpatchable-function-entry=8 would generate more nops than we expect. Because it treat nop opcode as 0x00000013 instead of 0x0001. Dump of assembler code for function dw_pcie_free_msi: 0xffffffff806fce94 <+0>: sd ra,-8(sp) 0xffffffff806fce98 <+4>: auipc ra,0xff90f 0xffffffff806fce9c <+8>: jalr -684(ra) # 0xffffffff8000bbec <ftrace_caller> 0xffffffff806fcea0 <+12>: ld ra,-8(sp) 0xffffffff806fcea4 <+16>: nop /* wasted */ 0xffffffff806fcea8 <+20>: nop /* wasted */ 0xffffffff806fceac <+24>: nop /* wasted */ 0xffffffff806fceb0 <+28>: nop /* wasted */ 0xffffffff806fceb4 <+0>: addi sp,sp,-48 0xffffffff806fceb8 <+4>: sd s0,32(sp) 0xffffffff806fcebc <+8>: sd s1,24(sp) 0xffffffff806fcec0 <+12>: sd s2,16(sp) 0xffffffff806fcec4 <+16>: sd s3,8(sp) 0xffffffff806fcec8 <+20>: sd ra,40(sp) 0xffffffff806fcecc <+24>: addi s0,sp,48 Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230112090603.1295340-3-guoren@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10riscv, mm: Perform BPF exhandler fixup on page faultBjörn Töpel1-4/+6
commit 416721ff05fddc58ca531b6f069de250301de6e5 upstream. Commit 21855cac82d3 ("riscv/mm: Prevent kernel module to access user memory without uaccess routines") added early exits/deaths for page faults stemming from accesses to user-space without using proper uaccess routines (where sstatus.SUM is set). Unfortunatly, this is too strict for some BPF programs, which relies on BPF exhandler fixups. These BPF programs loads "BTF pointers". A BTF pointers could either be a valid kernel pointer or NULL, but not a userspace address. Resolve the problem by calling the fixup handler in the early exit path. Fixes: 21855cac82d3 ("riscv/mm: Prevent kernel module to access user memory without uaccess routines") Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230214162515.184827-1-bjorn@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10riscv: jump_label: Fixup unaligned arch_static_branch functionAndy Chiu1-0/+2
commit 9ddfc3cd806081ce1f6c9c2f988cbb031f35d28f upstream. Runtime code patching must be done at a naturally aligned address, or we may execute on a partial instruction. We have encountered problems traced back to static jump functions during the test. We switched the tracer randomly for every 1~5 seconds on a dual-core QEMU setup and found the kernel sucking at a static branch where it jumps to itself. The reason is that the static branch was 2-byte but not 4-byte aligned. Then, the kernel would patch the instruction, either J or NOP, with two half-word stores if the machine does not have efficient unaligned accesses. Thus, moments exist where half of the NOP mixes with the other half of the J when transitioning the branch. In our particular case, on a little-endian machine, the upper half of the NOP was mixed with the lower part of the J when enabling the branch, resulting in a jump that jumped to itself. Conversely, it would result in a HINT instruction when disabling the branch, but it might not be observable. ARM64 does not have this problem since all instructions must be 4-byte aligned. Fixes: ebc00dde8a97 ("riscv: Add jump-label implementation") Link: https://lore.kernel.org/linux-riscv/20220913094252.3555240-6-andy.chiu@sifive.com/ Reviewed-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230206090440.1255001-1-guoren@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10riscv: mm: fix regression due to update_mmu_cache changeSergey Matyukevich1-1/+1
commit b49f700668fff7565b945dce823def79bff59bb0 upstream. This is a partial revert of the commit 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates"). Original commit included two loosely related changes serving the same purpose of fixing stale TLB entries causing user-space application crash: - introduce deferred per-ASID TLB flush for CPUs not running the task - switch to per-ASID TLB flush on all CPUs running the task in update_mmu_cache According to report and discussion in [1], the second part caused a regression on Renesas RZ/Five SoC. For now restore the old behavior of the update_mmu_cache. [1] https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/ Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates") Reported-by: "Lad, Prabhakar" <prabhakar.csengg@gmail.com> Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Link: trailer, so that it can be parsed with git's trailer functionality? Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230129211818.686557-1-geomatsi@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10riscv: Avoid enabling interrupts in die()Mattias Nissler1-2/+3
commit 130aee3fd9981297ff9354e5d5609cd59aafbbea upstream. While working on something else, I noticed that the kernel would start accepting interrupts again after crashing in an interrupt handler. Since the kernel is already in inconsistent state, enabling interrupts is dangerous and opens up risk of kernel state deteriorating further. Interrupts do get enabled via what looks like an unintended side effect of spin_unlock_irq, so switch to the more cautious spin_lock_irqsave/spin_unlock_irqrestore instead. Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code") Signed-off-by: Mattias Nissler <mnissler@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/r/20230215144828.3370316-1-mnissler@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10RISC-V: add a spin_shadow_stack declarationConor Dooley1-0/+1
commit eb9be8310c58c166f9fae3b71c0ad9d6741b4897 upstream. The patchwork automation reported a sparse complaint that spin_shadow_stack was not declared and should be static: ../arch/riscv/kernel/traps.c:335:15: warning: symbol 'spin_shadow_stack' was not declared. Should it be static? However, this is used in entry.S and therefore shouldn't be static. The same applies to the shadow_stack that this pseudo spinlock is trying to protect, so do like its charge and add a declaration to thread_info.h Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Fixes: 7e1864332fbc ("riscv: fix race when vmap stack overflow") Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230210185945.915806-1-conor@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>