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2024-06-26riscv: hwprobe: export Zca, Zcf, Zcd and Zcb ISA extensionsClément Léger
Export Zca, Zcf, Zcd and Zcb ISA extension through hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240619113529.676940-10-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: add ISA parsing for Zca, Zcf, Zcd and ZcbClément Léger
The Zc* standard extension for code reduction introduces new extensions. This patch adds support for Zca, Zcf, Zcd and Zcb. Zce, Zcmt and Zcmp are left out of this patch since they are targeting microcontrollers/ embedded CPUs instead of application processors. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240619113529.676940-9-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: add ISA extensions validation callbackClément Léger
Since a few extensions (Zicbom/Zicboz) already needs validation and future ones will need it as well (Zc*) add a validate() callback to struct riscv_isa_ext_data. This require to rework the way extensions are parsed and split it in two phases. First phase is isa string or isa extension list parsing and consists in enabling all the extensions in a temporary bitmask (source isa) without any validation. The second step "resolves" the final isa bitmap, handling potential missing dependencies. The mechanism is quite simple and simply validate each extension described in the source bitmap before enabling it in the resolved isa bitmap. validate() callbacks can return either 0 for success, -EPROBEDEFER if extension needs to be validated again at next loop. A previous ISA bitmap is kept to avoid looping multiple times if an extension dependencies are never satisfied until we reach a stable state. In order to avoid any potential infinite looping, allow looping a maximum of the number of extension we handle. Zicboz and Zicbom extensions are modified to use this validation mechanism. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240619113529.676940-8-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: hwprobe: export Zimop ISA extensionClément Léger
Export Zimop ISA extension through hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240619113529.676940-4-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: add ISA extension parsing for ZimopClément Léger
Add parsing for Zimop ISA extension which was ratified in commit 58220614a5f of the riscv-isa-manual. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240619113529.676940-3-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26Merge patch "riscv: stacktrace: convert arch_stack_walk() to noinstr"Palmer Dabbelt
This first patch in the larger series is a fix, so I'm merging it into fixes while the rest of the patch set is still under development. * b4-shazam-merge: riscv: stacktrace: convert arch_stack_walk() to noinstr Link: https://lore.kernel.org/r/20240613-dev-andyc-dyn-ftrace-v4-v1-0-1a538e12c01e@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: stacktrace: convert arch_stack_walk() to noinstrAndy Chiu
arch_stack_walk() is called intensively in function_graph when the kernel is compiled with CONFIG_TRACE_IRQFLAGS. As a result, the kernel logs a lot of arch_stack_walk and its sub-functions into the ftrace buffer. However, these functions should not appear on the trace log because they are part of the ftrace itself. This patch references what arm64 does for the smae function. So it further prevent the re-enter kprobe issue, which is also possible on riscv. Related-to: commit 0fbcd8abf337 ("arm64: Prohibit instrumentation on arch_stack_walk()") Fixes: 680341382da5 ("riscv: add CALLER_ADDRx support") Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240613-dev-andyc-dyn-ftrace-v4-v1-1-1a538e12c01e@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: patch: Flush the icache right after patching to avoid illegal insnsAlexandre Ghiti
We cannot delay the icache flush after patching some functions as we may have patched a function that will get called before the icache flush. The only way to completely avoid such scenario is by flushing the icache as soon as we patch a function. This will probably be costly as we don't batch the icache maintenance anymore. Fixes: 6ca445d8af0e ("riscv: Fix early ftrace nop patching") Reported-by: Conor Dooley <conor.dooley@microchip.com> Closes: https://lore.kernel.org/linux-riscv/20240613-lubricant-breath-061192a9489a@wendy/ Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20240624082141.153871-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26Merge patch series "riscv: Various text patching improvements"Palmer Dabbelt
Samuel Holland <samuel.holland@sifive.com> says: Here are a few changes to minimize calls to stop_machine() and flush_icache_*() in the various text patching functions, as well as to simplify the code. * b4-shazam-merge: riscv: Remove extra variable in patch_text_nosync() riscv: Use offset_in_page() in text patching functions riscv: Pass patch_text() the length in bytes riscv: Simplify text patching loops riscv: kprobes: Use patch_text_nosync() for insn slots riscv: jump_label: Simplify assembly syntax riscv: jump_label: Batch icache maintenance Link: https://lore.kernel.org/r/20240327160520.791322-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: Remove extra variable in patch_text_nosync()Samuel Holland
This cast is superfluous, and is incorrect anyway if compressed instructions may be present. Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240327160520.791322-8-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: Use offset_in_page() in text patching functionsSamuel Holland
This is a bit easier to parse than the equivalent bit manipulation. Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240327160520.791322-7-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: Pass patch_text() the length in bytesSamuel Holland
patch_text_nosync() already handles an arbitrary length of code, so this removes a superfluous loop and reduces the number of icache flushes. Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240327160520.791322-6-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: Simplify text patching loopsSamuel Holland
This reduces the number of variables and makes the code easier to parse. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240327160520.791322-5-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: kprobes: Use patch_text_nosync() for insn slotsSamuel Holland
These instructions are not yet visible to the rest of the system, so there is no need to do the whole stop_machine() dance. Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240327160520.791322-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: jump_label: Batch icache maintenanceSamuel Holland
Switch to the batched version of the jump label update functions so instruction cache maintenance is deferred until the end of the update. Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240327160520.791322-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-25syscalls: mmap(): use unsigned offset type consistentlyArnd Bergmann
Most architectures that implement the old-style mmap() with byte offset use 'unsigned long' as the type for that offset, but microblaze and riscv have the off_t type that is shared with userspace, matching the prototype in include/asm-generic/syscalls.h. Make this consistent by using an unsigned argument everywhere. This changes the behavior slightly, as the argument is shifted to a page number, and an user input with the top bit set would result in a negative page offset rather than a large one as we use elsewhere. For riscv, the 32-bit sys_mmap2() definition actually used a custom type that is different from the global declaration, but this was missed due to an incorrect type check. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-05-30riscv: vector: adjust minimum Vector requirement to ZVE32XAndy Chiu
Make has_vector() to check for ZVE32X. Every in-kernel usage of V that requires a more complicate version of V must then call out explicitly. Also, change riscv_v_first_use_handler(), and boot code that calls riscv_v_setup_vsize() to accept ZVE32X. Most kernel/user interfaces requires minimum of ZVE32X. Thus, programs compiled and run with ZVE32X should be supported by the kernel on most aspects. This includes context-switch, signal, ptrace, prctl, and hwprobe. One exception is that ELF_HWCAP returns 'V' only if full V is supported on the platform. This means that the system without a full V must not rely on ELF_HWCAP to tell whether it is allowable to execute Vector without first invoking a prctl() check. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Joel Granados <j.granados@samsung.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-7-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: hwprobe: add zve Vector subextensions into hwprobe interfaceAndy Chiu
The following Vector subextensions for "embedded" platforms are added into RISCV_HWPROBE_KEY_IMA_EXT_0: - ZVE32X - ZVE32F - ZVE64X - ZVE64F - ZVE64D Extensions ending with an X indicates that the platform doesn't have a vector FPU. Extensions ending with F/D mean that whether single (F) or double (D) precision vector operation is supported. The number 32 or 64 follows from ZVE tells the maximum element length. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-6-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: cpufeature: add zve32[xf] and zve64[xfd] isa detectionAndy Chiu
Multiple Vector subextensions are added. Also, the patch takes care of the dependencies of Vector subextensions by macro expansions. So, if some "embedded" platform only reports "zve64f" on the ISA string, the parser is able to expand it to zve32x zve32f zve64x and zve64f. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-5-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: cpufeature: call match_isa_ext() for single-letter extensionsAndy Chiu
Single-letter extensions may also imply multiple subextensions. For example, Vector extension implies zve64d, and zve64d implies zve64f. Extension parsing for "riscv,isa-extensions" has the ability to resolve the dependency by calling match_isa_ext(). This patch makes deprecated parser call the same function for single letter extensions. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-3-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: smp: fail booting up smp if inconsistent vlen is detectedAndy Chiu
Currently we only support Vector for SMP platforms, that is, all SMP cores have the same vlenb. If we happen to detect a mismatching vlen, it is better to just fail bootting it up to prevent further race/scheduling issues. Also, move .Lsecondary_park forward and chage `tail smp_callin` into a regular call in the early assembly. So a core would be parked right after a return from smp_callin. Note that a successful smp_callin does not return. Fixes: 7017858eb2d7 ("riscv: Introduce riscv_v_vsize to record size of Vector context") Reported-by: Conor Dooley <conor.dooley@microchip.com> Closes: https://lore.kernel.org/linux-riscv/20240228-vicinity-cornstalk-4b8eb5fe5730@spud/ Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-2-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: vector: add a comment when calling riscv_setup_vsize()Andy Chiu
The function would fail when it detects the calling hart's vlen doesn't match the first one's. The boot hart is the first hart calling this function during riscv_fill_hwcap, so it is impossible to fail here. Add a comment about this behavior. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-1-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: prevent pt_regs corruption for secondary idle threadsSergey Matyukevich
Top of the kernel thread stack should be reserved for pt_regs. However this is not the case for the idle threads of the secondary boot harts. Their stacks overlap with their pt_regs, so both may get corrupted. Similar issue has been fixed for the primary hart, see c7cdd96eca28 ("riscv: prevent stack corruption by reserving task_pt_regs(p) early"). However that fix was not propagated to the secondary harts. The problem has been noticed in some CPU hotplug tests with V enabled. The function smp_callin stored several registers on stack, corrupting top of pt_regs structure including status field. As a result, kernel attempted to save or restore inexistent V context. Fixes: 9a2451f18663 ("RISC-V: Avoid using per cpu array for ordered booting") Fixes: 2875fe056156 ("RISC-V: Add cpu_ops and modify default booting method") Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240523084327.2013211-1-geomatsi@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-24Merge tag 'riscv-for-linus-6.10-mw2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Palmer Dabbelt: - The compression format used for boot images is now configurable at build time, and these formats are shown in `make help` - access_ok() has been optimized - A pair of performance bugs have been fixed in the uaccess handlers - Various fixes and cleanups, including one for the IMSIC build failure and one for the early-boot ftrace illegal NOPs bug * tag 'riscv-for-linus-6.10-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Fix early ftrace nop patching irqchip: riscv-imsic: Fixup riscv_ipi_set_virq_range() conflict riscv: selftests: Add signal handling vector tests riscv: mm: accelerate pagefault when badaccess riscv: uaccess: Relax the threshold for fast path riscv: uaccess: Allow the last potential unrolled copy riscv: typo in comment for get_f64_reg Use bool value in set_cpu_online() riscv: selftests: Add hwprobe binaries to .gitignore riscv: stacktrace: fixed walk_stackframe() ftrace: riscv: move from REGS to ARGS riscv: do not select MODULE_SECTIONS by default riscv: show help string for riscv-specific targets riscv: make image compression configurable riscv: cpufeature: Fix extension subset checking riscv: cpufeature: Fix thead vector hwcap removal riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context riscv: force PAGE_SIZE linear mapping if debug_pagealloc is enabled riscv: Define TASK_SIZE_MAX for __access_ok() riscv: Remove PGDIR_SIZE_L3 and TASK_SIZE_MIN
2024-05-23riscv: Fix early ftrace nop patchingAlexandre Ghiti
Commit c97bf629963e ("riscv: Fix text patching when IPI are used") converted ftrace_make_nop() to use patch_insn_write() which does not emit any icache flush relying entirely on __ftrace_modify_code() to do that. But we missed that ftrace_make_nop() was called very early directly when converting mcount calls into nops (actually on riscv it converts 2B nops emitted by the compiler into 4B nops). This caused crashes on multiple HW as reported by Conor and Björn since the booting core could have half-patched instructions in its icache which would trigger an illegal instruction trap: fix this by emitting a local flush icache when early patching nops. Fixes: c97bf629963e ("riscv: Fix text patching when IPI are used") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20240523115134.70380-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22Merge tag 'mm-nonmm-stable-2024-05-22-17-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more non-mm updates from Andrew Morton: - A series ("kbuild: enable more warnings by default") from Arnd Bergmann which enables a number of additional build-time warnings. We fixed all the fallout which we could find, there may still be a few stragglers. - Samuel Holland has developed the series "Unified cross-architecture kernel-mode FPU API". This does a lot of consolidation of per-architecture kernel-mode FPU usage and enables the use of newer AMD GPUs on RISC-V. - Tao Su has fixed some selftests build warnings in the series "Selftests: Fix compilation warnings due to missing _GNU_SOURCE definition". - This pull also includes a nilfs2 fixup from Ryusuke Konishi. * tag 'mm-nonmm-stable-2024-05-22-17-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (23 commits) nilfs2: make block erasure safe in nilfs_finish_roll_forward() selftests/harness: use 1024 in place of LINE_MAX Revert "selftests/harness: remove use of LINE_MAX" selftests/fpu: allow building on other architectures selftests/fpu: move FP code to a separate translation unit drm/amd/display: use ARCH_HAS_KERNEL_FPU_SUPPORT drm/amd/display: only use hard-float, not altivec on powerpc riscv: add support for kernel-mode FPU x86: implement ARCH_HAS_KERNEL_FPU_SUPPORT powerpc: implement ARCH_HAS_KERNEL_FPU_SUPPORT LoongArch: implement ARCH_HAS_KERNEL_FPU_SUPPORT lib/raid6: use CC_FLAGS_FPU for NEON CFLAGS arm64: crypto: use CC_FLAGS_FPU for NEON CFLAGS arm64: implement ARCH_HAS_KERNEL_FPU_SUPPORT ARM: crypto: use CC_FLAGS_FPU for NEON CFLAGS ARM: implement ARCH_HAS_KERNEL_FPU_SUPPORT arch: add ARCH_HAS_KERNEL_FPU_SUPPORT x86/fpu: fix asm/fpu/types.h include guard kbuild: enable -Wcast-function-type-strict unconditionally kbuild: enable -Wformat-truncation on clang ...
2024-05-22Merge patch series "riscv: Extension parsing fixes"Palmer Dabbelt
Charlie Jenkins <charlie@rivosinc.com> says: This series contains two minor fixes for the extension parsing in cpufeature.c. Some T-Head boards without vector 1.0 support report "v" in the isa string in their DT which will cause the kernel to run vector code. The code to blacklist "v" from these boards was doing so by using riscv_cached_mvendorid() which has not been populated at the time of extension parsing. This fix instead greedily reads the mvendorid CSR of the boot hart to determine if the cpu is from T-Head. The other fix is for an incorrect indexing bug. riscv extensions sometimes imply other extensions. When adding these "subset" extensions to the hardware capabilities array, they need to be checked if they are valid. The current code only checks if the extension that is including other extensions is valid and not the subset extensions. These patches were previously included in: https://lore.kernel.org/lkml/20240420-dev-charlie-support_thead_vector_6_9-v3-0-67cff4271d1d@rivosinc.com/ * b4-shazam-merge: riscv: cpufeature: Fix extension subset checking riscv: cpufeature: Fix thead vector hwcap removal Link: https://lore.kernel.org/r/20240502-cpufeature_fixes-v4-0-b3d1a088722d@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22riscv: typo in comment for get_f64_regXingyou Chen
Signed-off-by: Xingyou Chen <rockrush@rockwork.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20240317055556.9449-1-rockrush@rockwork.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22Use bool value in set_cpu_online()Zhao Ke
The declaration of set_cpu_online() takes a bool value. So replace int here to make it consistent with the declaration. Signed-off-by: Zhao Ke <ke.zhao@shingroup.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240318065404.123668-1-ke.zhao@shingroup.cn Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22riscv: stacktrace: fixed walk_stackframe()Matthew Bystrin
If the load access fault occures in a leaf function (with CONFIG_FRAME_POINTER=y), when wrong stack trace will be displayed: [<ffffffff804853c2>] regmap_mmio_read32le+0xe/0x1c ---[ end trace 0000000000000000 ]--- Registers dump: ra 0xffffffff80485758 <regmap_mmio_read+36> sp 0xffffffc80200b9a0 fp 0xffffffc80200b9b0 pc 0xffffffff804853ba <regmap_mmio_read32le+6> Stack dump: 0xffffffc80200b9a0: 0xffffffc80200b9e0 0xffffffc80200b9e0 0xffffffc80200b9b0: 0xffffffff8116d7e8 0x0000000000000100 0xffffffc80200b9c0: 0xffffffd8055b9400 0xffffffd8055b9400 0xffffffc80200b9d0: 0xffffffc80200b9f0 0xffffffff8047c526 0xffffffc80200b9e0: 0xffffffc80200ba30 0xffffffff8047fe9a The assembler dump of the function preambula: add sp,sp,-16 sd s0,8(sp) add s0,sp,16 In the fist stack frame, where ra is not stored on the stack we can observe: 0(sp) 8(sp) .---------------------------------------------. sp->| frame->fp | frame->ra (saved fp) | |---------------------------------------------| fp->| .... | .... | |---------------------------------------------| | | | and in the code check is performed: if (regs && (regs->epc == pc) && (frame->fp & 0x7)) I see no reason to check frame->fp value at all, because it is can be uninitialized value on the stack. A better way is to check frame->ra to be an address on the stack. After the stacktrace shows as expect: [<ffffffff804853c2>] regmap_mmio_read32le+0xe/0x1c [<ffffffff80485758>] regmap_mmio_read+0x24/0x52 [<ffffffff8047c526>] _regmap_bus_reg_read+0x1a/0x22 [<ffffffff8047fe9a>] _regmap_read+0x5c/0xea [<ffffffff80480376>] _regmap_update_bits+0x76/0xc0 ... ---[ end trace 0000000000000000 ]--- As pointed by Samuel Holland it is incorrect to remove check of the stackframe entirely. Changes since v2 [2]: - Add accidentally forgotten curly brace Changes since v1 [1]: - Instead of just dropping frame->fp check, replace it with validation of frame->ra, which should be a stack address. - Move frame pointer validation into the separate function. [1] https://lore.kernel.org/linux-riscv/20240426072701.6463-1-dev.mbstr@gmail.com/ [2] https://lore.kernel.org/linux-riscv/20240521131314.48895-1-dev.mbstr@gmail.com/ Fixes: f766f77a74f5 ("riscv/stacktrace: Fix stack output without ra on the stack top") Signed-off-by: Matthew Bystrin <dev.mbstr@gmail.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240521191727.62012-1-dev.mbstr@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22ftrace: riscv: move from REGS to ARGSPuranjay Mohan
This commit replaces riscv's support for FTRACE_WITH_REGS with support for FTRACE_WITH_ARGS. This is required for the ongoing effort to stop relying on stop_machine() for RISCV's implementation of ftrace. The main relevant benefit that this change will bring for the above use-case is that now we don't have separate ftrace_caller and ftrace_regs_caller trampolines. This will allow the callsite to call ftrace_caller by modifying a single instruction. Now the callsite can do something similar to: When not tracing: | When tracing: func: func: auipc t0, ftrace_caller_top auipc t0, ftrace_caller_top nop <=========<Enable/Disable>=========> jalr t0, ftrace_caller_bottom [...] [...] The above assumes that we are dropping the support of calling a direct trampoline from the callsite. We need to drop this as the callsite can't change the target address to call, it can only enable/disable a call to a preset target (ftrace_caller in the above diagram). We can later optimize this by calling an intermediate dispatcher trampoline before ftrace_caller. Currently, ftrace_regs_caller saves all CPU registers in the format of struct pt_regs and allows the tracer to modify them. We don't need to save all of the CPU registers because at function entry only a subset of pt_regs is live: |----------+----------+---------------------------------------------| | Register | ABI Name | Description | |----------+----------+---------------------------------------------| | x1 | ra | Return address for traced function | | x2 | sp | Stack pointer | | x5 | t0 | Return address for ftrace_caller trampoline | | x8 | s0/fp | Frame pointer | | x10-11 | a0-1 | Function arguments/return values | | x12-17 | a2-7 | Function arguments | |----------+----------+---------------------------------------------| See RISCV calling convention[1] for the above table. Saving just the live registers decreases the amount of stack space required from 288 Bytes to 112 Bytes. Basic testing was done with this on the VisionFive 2 development board. Note: - Moving from REGS to ARGS will mean that RISCV will stop supporting KPROBES_ON_FTRACE as it requires full pt_regs to be saved. - KPROBES_ON_FTRACE will be supplanted by FPROBES see [2]. [1] https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf [2] https://lore.kernel.org/all/170887410337.564249.6360118840946697039.stgit@devnote2/ Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Tested-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20240405142453.4187-1-puranjay@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22Merge tag 'riscv-for-linus-6.10-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Add byte/half-word compare-and-exchange, emulated via LR/SC loops - Support for Rust - Support for Zihintpause in hwprobe - Add PR_RISCV_SET_ICACHE_FLUSH_CTX prctl() - Support lockless lockrefs * tag 'riscv-for-linus-6.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits) riscv: defconfig: Enable CONFIG_CLK_SOPHGO_CV1800 riscv: select ARCH_HAS_FAST_MULTIPLIER riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required riscv: Annotate pgtable_l{4,5}_enabled with __ro_after_init riscv: Remove redundant CONFIG_64BIT from pgtable_l{4,5}_enabled riscv: mm: Always use an ASID to flush mm contexts riscv: mm: Preserve global TLB entries when switching contexts riscv: mm: Make asid_bits a local variable riscv: mm: Use a fixed layout for the MM context ID riscv: mm: Introduce cntx2asid/cntx2version helper macros riscv: Avoid TLB flush loops when affected by SiFive CIP-1200 riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma riscv: mm: Combine the SMP and UP TLB flush code riscv: Only send remote fences when some other CPU is online riscv: mm: Broadcast kernel TLB flushes only when needed riscv: Use IPIs for remote cache/TLB flushes by default riscv: Factor out page table TLB synchronization riscv: Flush the instruction cache during SMP bringup riscv: hwprobe: export Zihintpause ISA extension riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code ...
2024-05-22riscv: cpufeature: Fix extension subset checkingCharlie Jenkins
This loop is supposed to check if ext->subset_ext_ids[j] is valid, rather than if ext->subset_ext_ids[i] is valid, before setting the extension id ext->subset_ext_ids[j] in isainfo->isa. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Fixes: 0d8295ed975b ("riscv: add ISA extension parsing for scalar crypto") Link: https://lore.kernel.org/r/20240502-cpufeature_fixes-v4-2-b3d1a088722d@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22riscv: cpufeature: Fix thead vector hwcap removalCharlie Jenkins
The riscv_cpuinfo struct that contains mvendorid and marchid is not populated until all harts are booted which happens after the DT parsing. Use the mvendorid/marchid from the boot hart to determine if the DT contains an invalid V. Fixes: d82f32202e0d ("RISC-V: Ignore V from the riscv,isa DT property on older T-Head CPUs") Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20240502-cpufeature_fixes-v4-1-b3d1a088722d@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-19riscv: add support for kernel-mode FPUSamuel Holland
This is motivated by the amdgpu DRM driver, which needs floating-point code to support recent hardware. That code is not performance-critical, so only provide a minimal non-preemptible implementation for now. Support is limited to riscv64 because riscv32 requires runtime (libgcc) assistance to convert between doubles and 64-bit integers. Link: https://lkml.kernel.org/r/20240329072441.591471-12-samuel.holland@sifive.com Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Christian König <christian.koenig@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: WANG Xuerui <git@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-18Merge tag 'kbuild-v6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Avoid 'constexpr', which is a keyword in C23 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of 'dt_binding_check' - Fix weak references to avoid GOT entries in position-independent code generation - Convert the last use of 'optional' property in arch/sh/Kconfig - Remove support for the 'optional' property in Kconfig - Remove support for Clang's ThinLTO caching, which does not work with the .incbin directive - Change the semantics of $(src) so it always points to the source directory, which fixes Makefile inconsistencies between upstream and downstream - Fix 'make tar-pkg' for RISC-V to produce a consistent package - Provide reasonable default coverage for objtool, sanitizers, and profilers - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc. - Remove the last use of tristate choice in drivers/rapidio/Kconfig - Various cleanups and fixes in Kconfig * tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits) kconfig: use sym_get_choice_menu() in sym_check_prop() rapidio: remove choice for enumeration kconfig: lxdialog: remove initialization with A_NORMAL kconfig: m/nconf: merge two item_add_str() calls kconfig: m/nconf: remove dead code to display value of bool choice kconfig: m/nconf: remove dead code to display children of choice members kconfig: gconf: show checkbox for choice correctly kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal Makefile: remove redundant tool coverage variables kbuild: provide reasonable defaults for tool coverage modules: Drop the .export_symbol section from the final modules kconfig: use menu_list_for_each_sym() in sym_check_choice_deps() kconfig: use sym_get_choice_menu() in conf_write_defconfig() kconfig: add sym_get_choice_menu() helper kconfig: turn defaults and additional prompt for choice members into error kconfig: turn missing prompt for choice members into error kconfig: turn conf_choice() into void function kconfig: use linked list in sym_set_changed() kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED kconfig: gconf: remove debug code ...
2024-05-17Merge tag 'probes-v6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes updates from Masami Hiramatsu: - tracing/probes: Add new pseudo-types %pd and %pD support for dumping dentry name from 'struct dentry *' and file name from 'struct file *' - uprobes performance optimizations: - Speed up the BPF uprobe event by delaying the fetching of the uprobe event arguments that are not used in BPF - Avoid locking by speculatively checking whether uprobe event is valid - Reduce lock contention by using read/write_lock instead of spinlock for uprobe list operation. This improved BPF uprobe benchmark result 43% on average - rethook: Remove non-fatal warning messages when tracing stack from BPF and skip rcu_is_watching() validation in rethook if possible - objpool: Optimize objpool (which is used by kretprobes and fprobe as rethook backend storage) by inlining functions and avoid caching nr_cpu_ids because it is a const value - fprobe: Add entry/exit callbacks types (code cleanup) - kprobes: Check ftrace was killed in kprobes if it uses ftrace * tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: kprobe/ftrace: bail out if ftrace was killed selftests/ftrace: Fix required features for VFS type test case objpool: cache nr_possible_cpus() and avoid caching nr_cpu_ids objpool: enable inlining objpool_push() and objpool_pop() operations rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get() ftrace: make extra rcu_is_watching() validation check optional uprobes: reduce contention on uprobes_tree access rethook: Remove warning messages printed for finding return address of a frame. fprobe: Add entry/exit callbacks types selftests/ftrace: add fprobe test cases for VFS type "%pd" and "%pD" selftests/ftrace: add kprobe test cases for VFS type "%pd" and "%pD" Documentation: tracing: add new type '%pd' and '%pD' for kprobe tracing/probes: support '%pD' type for print struct file's name tracing/probes: support '%pd' type for print struct dentry's name uprobes: add speculative lockless system-wide uprobe filter check uprobes: prepare uprobe args buffer lazily uprobes: encapsulate preparation of uprobe args buffer
2024-05-16kprobe/ftrace: bail out if ftrace was killedStephen Brennan
If an error happens in ftrace, ftrace_kill() will prevent disarming kprobes. Eventually, the ftrace_ops associated with the kprobes will be freed, yet the kprobes will still be active, and when triggered, they will use the freed memory, likely resulting in a page fault and panic. This behavior can be reproduced quite easily, by creating a kprobe and then triggering a ftrace_kill(). For simplicity, we can simulate an ftrace error with a kernel module like [1]: [1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer sudo perf probe --add commit_creds sudo perf trace -e probe:commit_creds # In another terminal make sudo insmod ftrace_killer.ko # calls ftrace_kill(), simulating bug # Back to perf terminal # ctrl-c sudo perf probe --del commit_creds After a short period, a page fault and panic would occur as the kprobe continues to execute and uses the freed ftrace_ops. While ftrace_kill() is supposed to be used only in extreme circumstances, it is invoked in FTRACE_WARN_ON() and so there are many places where an unexpected bug could be triggered, yet the system may continue operating, possibly without the administrator noticing. If ftrace_kill() does not panic the system, then we should do everything we can to continue operating, rather than leave a ticking time bomb. Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/ Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Guo Ren <guoren@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - Move a lot of state that was previously stored on a per vcpu basis into a per-CPU area, because it is only pertinent to the host while the vcpu is loaded. This results in better state tracking, and a smaller vcpu structure. - Add full handling of the ERET/ERETAA/ERETAB instructions in nested virtualisation. The last two instructions also require emulating part of the pointer authentication extension. As a result, the trap handling of pointer authentication has been greatly simplified. - Turn the global (and not very scalable) LPI translation cache into a per-ITS, scalable cache, making non directly injected LPIs much cheaper to make visible to the vcpu. - A batch of pKVM patches, mostly fixes and cleanups, as the upstreaming process seems to be resuming. Fingers crossed! - Allocate PPIs and SGIs outside of the vcpu structure, allowing for smaller EL2 mapping and some flexibility in implementing more or less than 32 private IRQs. - Purge stale mpidr_data if a vcpu is created after the MPIDR map has been created. - Preserve vcpu-specific ID registers across a vcpu reset. - Various minor cleanups and improvements. LoongArch: - Add ParaVirt IPI support - Add software breakpoint support - Add mmio trace events support RISC-V: - Support guest breakpoints using ebreak - Introduce per-VCPU mp_state_lock and reset_cntx_lock - Virtualize SBI PMU snapshot and counter overflow interrupts - New selftests for SBI PMU and Guest ebreak - Some preparatory work for both TDX and SNP page fault handling. This also cleans up the page fault path, so that the priorities of various kinds of fauls (private page, no memory, write to read-only slot, etc.) are easier to follow. x86: - Minimize amount of time that shadow PTEs remain in the special REMOVED_SPTE state. This is a state where the mmu_lock is held for reading but concurrent accesses to the PTE have to spin; shortening its use allows other vCPUs to repopulate the zapped region while the zapper finishes tearing down the old, defunct page tables. - Advertise the max mappable GPA in the "guest MAXPHYADDR" CPUID field, which is defined by hardware but left for software use. This lets KVM communicate its inability to map GPAs that set bits 51:48 on hosts without 5-level nested page tables. Guest firmware is expected to use the information when mapping BARs; this avoids that they end up at a legal, but unmappable, GPA. - Fixed a bug where KVM would not reject accesses to MSR that aren't supposed to exist given the vCPU model and/or KVM configuration. - As usual, a bunch of code cleanups. x86 (AMD): - Implement a new and improved API to initialize SEV and SEV-ES VMs, which will also be extendable to SEV-SNP. The new API specifies the desired encryption in KVM_CREATE_VM and then separately initializes the VM. The new API also allows customizing the desired set of VMSA features; the features affect the measurement of the VM's initial state, and therefore enabling them cannot be done tout court by the hypervisor. While at it, the new API includes two bugfixes that couldn't be applied to the old one without a flag day in userspace or without affecting the initial measurement. When a SEV-ES VM is created with the new VM type, KVM_GET_REGS/KVM_SET_REGS and friends are rejected once the VMSA has been encrypted. Also, the FPU and AVX state will be synchronized and encrypted too. - Support for GHCB version 2 as applicable to SEV-ES guests. This, once more, is only accessible when using the new KVM_SEV_INIT2 flow for initialization of SEV-ES VMs. x86 (Intel): - An initial bunch of prerequisite patches for Intel TDX were merged. They generally don't do anything interesting. The only somewhat user visible change is a new debugging mode that checks that KVM's MMU never triggers a #VE virtualization exception in the guest. - Clear vmcs.EXIT_QUALIFICATION when synthesizing an EPT Misconfig VM-Exit to L1, as per the SDM. Generic: - Use vfree() instead of kvfree() for allocations that always use vcalloc() or __vcalloc(). - Remove .change_pte() MMU notifier - the changes to non-KVM code are small and Andrew Morton asked that I also take those through the KVM tree. The callback was only ever implemented by KVM (which was also the original user of MMU notifiers) but it had been nonfunctional ever since calls to set_pte_at_notify were wrapped with invalidate_range_start and invalidate_range_end... in 2012. Selftests: - Enhance the demand paging test to allow for better reporting and stressing of UFFD performance. - Convert the steal time test to generate TAP-friendly output. - Fix a flaky false positive in the xen_shinfo_test due to comparing elapsed time across two different clock domains. - Skip the MONITOR/MWAIT test if the host doesn't actually support MWAIT. - Avoid unnecessary use of "sudo" in the NX hugepage test wrapper shell script, to play nice with running in a minimal userspace environment. - Allow skipping the RSEQ test's sanity check that the vCPU was able to complete a reasonable number of KVM_RUNs, as the assert can fail on a completely valid setup. If the test is run on a large-ish system that is otherwise idle, and the test isn't affined to a low-ish number of CPUs, the vCPU task can be repeatedly migrated to CPUs that are in deep sleep states, which results in the vCPU having very little net runtime before the next migration due to high wakeup latencies. - Define _GNU_SOURCE for all selftests to fix a warning that was introduced by a change to kselftest_harness.h late in the 6.9 cycle, and because forcing every test to #define _GNU_SOURCE is painful. - Provide a global pseudo-RNG instance for all tests, so that library code can generate random, but determinstic numbers. - Use the global pRNG to randomly force emulation of select writes from guest code on x86, e.g. to help validate KVM's emulation of locked accesses. - Allocate and initialize x86's GDT, IDT, TSS, segments, and default exception handlers at VM creation, instead of forcing tests to manually trigger the related setup. Documentation: - Fix a goof in the KVM_CREATE_GUEST_MEMFD documentation" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (225 commits) selftests/kvm: remove dead file KVM: selftests: arm64: Test vCPU-scoped feature ID registers KVM: selftests: arm64: Test that feature ID regs survive a reset KVM: selftests: arm64: Store expected register value in set_id_regs KVM: selftests: arm64: Rename helper in set_id_regs to imply VM scope KVM: arm64: Only reset vCPU-scoped feature ID regs once KVM: arm64: Reset VM feature ID regs from kvm_reset_sys_regs() KVM: arm64: Rename is_id_reg() to imply VM scope KVM: arm64: Destroy mpidr_data for 'late' vCPU creation KVM: arm64: Use hVHE in pKVM by default on CPUs with VHE support KVM: arm64: Fix hvhe/nvhe early alias parsing KVM: SEV: Allow per-guest configuration of GHCB protocol version KVM: SEV: Add GHCB handling for termination requests KVM: SEV: Add GHCB handling for Hypervisor Feature Support requests KVM: SEV: Add support to handle AP reset MSR protocol KVM: x86: Explicitly zero kvm_caps during vendor module load KVM: x86: Fully re-initialize supported_mce_cap on vendor module load KVM: x86: Fully re-initialize supported_vm_types on vendor module load KVM: x86/mmu: Sanity check that __kvm_faultin_pfn() doesn't create noslot pfns KVM: x86/mmu: Initialize kvm_page_fault's pfn and hva to error values ...
2024-05-14Makefile: remove redundant tool coverage variablesMasahiro Yamada
Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
2024-05-14arch: make execmem setup available regardless of CONFIG_MODULESMike Rapoport (IBM)
execmem does not depend on modules, on the contrary modules use execmem. To make execmem available when CONFIG_MODULES=n, for instance for kprobes, split execmem_params initialization out from arch/*/kernel/module.c and compile it when CONFIG_EXECMEM=y Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14riscv: extend execmem_params for generated code allocationsMike Rapoport (IBM)
The memory allocations for kprobes and BPF on RISC-V are not placed in the modules area and these custom allocations are implemented with overrides of alloc_insn_page() and bpf_jit_alloc_exec(). Define MODULES_VADDR and MODULES_END as VMALLOC_START and VMALLOC_END for 32 bit and slightly reorder execmem_params initialization to support both 32 and 64 bit variants, define EXECMEM_KPROBES and EXECMEM_BPF ranges in riscv::execmem_params and drop overrides of alloc_insn_page() and bpf_jit_alloc_exec(). Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14mm/execmem, arch: convert simple overrides of module_alloc to execmemMike Rapoport (IBM)
Several architectures override module_alloc() only to define address range for code allocations different than VMALLOC address space. Provide a generic implementation in execmem that uses the parameters for address space ranges, required alignment and page protections provided by architectures. The architectures must fill execmem_info structure and implement execmem_arch_setup() that returns a pointer to that structure. This way the execmem initialization won't be called from every architecture, but rather from a central place, namely a core_initcall() in execmem. The execmem provides execmem_alloc() API that wraps __vmalloc_node_range() with the parameters defined by the architectures. If an architecture does not implement execmem_arch_setup(), execmem_alloc() will fall back to module_alloc(). Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Song Liu <song@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-10kbuild: use $(src) instead of $(srctree)/$(src) for source directoryMasahiro Yamada
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-04-30Merge patch series "riscv: ASID-related and UP-related TLB flush enhancements"Palmer Dabbelt
Samuel Holland <samuel.holland@sifive.com> says: This series converts uniprocessor kernel builds to use the same TLB flushing code as SMP builds, to take advantage of batching and existing range- and ASID-based TLB flush optimizations. It optimizes out IPIs and SBI calls based on the online CPU count, which also covers the scenario where SMP was enabled at build time but only one CPU is present/online. A final optimization is to use single-ASID flushes wherever possible, to avoid unnecessary TLB misses for kernel mappings. This series has a semantic conflict with the AIA patches that are in linux-next due to the removal of the third parameter of riscv_ipi_set_virq_range(), which is called from imsic_ipi_domain_init() in drivers/irqchip/irq-riscv-imsic-early.c. The resolution is to remove the extra argument from the call site. Here are some numbers from D1 which show the performance impact: v6.9-rc1: System Benchmarks Partial Index BASELINE RESULT INDEX Execl Throughput 43.0 198.5 46.2 File Copy 1024 bufsize 2000 maxblocks 3960.0 73934.4 186.7 File Copy 256 bufsize 500 maxblocks 1655.0 20242.6 122.3 File Copy 4096 bufsize 8000 maxblocks 5800.0 197706.4 340.9 Pipe Throughput 12440.0 176974.2 142.3 Pipe-based Context Switching 4000.0 23626.8 59.1 Process Creation 126.0 449.9 35.7 Shell Scripts (1 concurrent) 42.4 544.4 128.4 Shell Scripts (16 concurrent) --- 35.3 --- Shell Scripts (8 concurrent) 6.0 71.6 119.3 System Call Overhead 15000.0 248072.6 165.4 ======== System Benchmarks Index Score (Partial Only) 110.6 v6.9-rc1 + this patch series: System Benchmarks Partial Index BASELINE RESULT INDEX Execl Throughput 43.0 196.8 45.8 File Copy 1024 bufsize 2000 maxblocks 3960.0 71782.2 181.3 File Copy 256 bufsize 500 maxblocks 1655.0 21269.4 128.5 File Copy 4096 bufsize 8000 maxblocks 5800.0 199424.0 343.8 Pipe Throughput 12440.0 196468.6 157.9 Pipe-based Context Switching 4000.0 24261.8 60.7 Process Creation 126.0 459.0 36.4 Shell Scripts (1 concurrent) 42.4 543.8 128.2 Shell Scripts (16 concurrent) --- 35.5 --- Shell Scripts (8 concurrent) 6.0 71.7 119.6 System Call Overhead 15000.0 259415.2 172.9 ======== System Benchmarks Index Score (Partial Only) 113.0 * b4-shazam-lts: riscv: mm: Always use an ASID to flush mm contexts riscv: mm: Preserve global TLB entries when switching contexts riscv: mm: Make asid_bits a local variable riscv: mm: Use a fixed layout for the MM context ID riscv: mm: Introduce cntx2asid/cntx2version helper macros riscv: Avoid TLB flush loops when affected by SiFive CIP-1200 riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma riscv: mm: Combine the SMP and UP TLB flush code riscv: Only send remote fences when some other CPU is online riscv: mm: Broadcast kernel TLB flushes only when needed riscv: Use IPIs for remote cache/TLB flushes by default riscv: Factor out page table TLB synchronization riscv: Flush the instruction cache during SMP bringup Link: https://lore.kernel.org/r/20240327045035.368512-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-30Merge patch series "riscv: fix patching with IPI"Palmer Dabbelt
Alexandre Ghiti <alexghiti@rivosinc.com> says: patch 1 removes a useless memory barrier and patch 2 actually fixes the issue with IPI in the patching code. * b4-shazam-merge: riscv: Fix text patching when IPI are used riscv: Remove superfluous smp_mb() Link: https://lore.kernel.org/r/20240229121056.203419-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-29riscv: Use IPIs for remote cache/TLB flushes by defaultSamuel Holland
An IPI backend is always required in an SMP configuration, but an SBI implementation is not. For example, SBI will be unavailable when the kernel runs in M mode. For this reason, consider IPI delivery of cache and TLB flushes to be the base case, and any other implementation (such as the SBI remote fence extension) to be an optimization. Generally, if IPIs can be delivered without firmware assistance, they are assumed to be faster than SBI calls due to the SBI context switch overhead. However, when SBI is used as the IPI backend, then the context switch cost must be paid anyway, and performing the cache/TLB flush directly in the SBI implementation is more efficient than injecting an interrupt to S-mode. This is the only existing scenario where riscv_ipi_set_virq_range() is called with use_for_rfence set to false. sbi_ipi_init() already checks riscv_ipi_have_virq_range(), so it only calls riscv_ipi_set_virq_range() when no other IPI device is available. This allows moving the static key and dropping the use_for_rfence parameter. This decouples the static key from the irqchip driver probe order. Furthermore, the static branch only makes sense when CONFIG_RISCV_SBI is enabled. Optherwise, IPIs must be used. Add a fallback definition of riscv_use_sbi_for_rfence() which handles this case and removes the need to check CONFIG_RISCV_SBI elsewhere, such as in cacheflush.c. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240327045035.368512-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-29riscv: Flush the instruction cache during SMP bringupSamuel Holland
Instruction cache flush IPIs are sent only to CPUs in cpu_online_mask, so they will not target a CPU until it calls set_cpu_online() earlier in smp_callin(). As a result, if instruction memory is modified between the CPU coming out of reset and that point, then its instruction cache may contain stale data. Therefore, the instruction cache must be flushed after the set_cpu_online() synchronization point. Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240327045035.368512-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-28riscv: hwprobe: export Zihintpause ISA extensionClément Léger
Export the Zihintpause ISA extension through hwprobe which allows using "pause" instructions. Some userspace applications (OpenJDK for instance) uses this to handle some locking back-off. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240221083108.1235311-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>