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2025-07-16riscv: traps_misaligned: properly sign extend value in misaligned load handlerAndreas Schwab
Add missing cast to signed long. Signed-off-by: Andreas Schwab <schwab@suse.de> Fixes: 956d705dd279 ("riscv: Unaligned load/store handling for M_MODE") Tested-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/mvmikk0goil.fsf@suse.de Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-23Revert "riscv: misaligned: fix sleeping function called during misaligned ↵Nam Cao
access handling" This reverts commit 61a74ad25462 ("riscv: misaligned: fix sleeping function called during misaligned access handling"). The commit addresses a sleeping in atomic context problem, but it is not the correct fix as explained by Clément: "Using nofault would lead to failure to read from user memory that is paged out for instance. This is not really acceptable, we should handle user misaligned access even at an address that would generate a page fault." This bug has been properly fixed by commit 453805f0a28f ("riscv: misaligned: enable IRQs while handling misaligned accesses"). Revert this improper fix. Link: https://lore.kernel.org/linux-riscv/b779beed-e44e-4a5e-9551-4647682b0d21@rivosinc.com/ Signed-off-by: Nam Cao <namcao@linutronix.de> Cc: stable@vger.kernel.org Reviewed-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Fixes: 61a74ad25462 ("riscv: misaligned: fix sleeping function called during misaligned access handling") Link: https://lore.kernel.org/r/20250620110939.1642735-1-namcao@linutronix.de Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-05Merge patch series "riscv: add SBI FWFT misaligned exception delegation support"Palmer Dabbelt
Clément Léger <cleger@rivosinc.com> says: The SBI Firmware Feature extension allows the S-mode to request some specific features (either hardware or software) to be enabled. This series uses this extension to request misaligned access exception delegation to S-mode in order to let the kernel handle it. It also adds support for the KVM FWFT SBI extension based on the misaligned access handling infrastructure. FWFT SBI extension is part of the SBI V3.0 specifications [1]. It can be tested using the qemu provided at [2] which contains the series from [3]. Upstream kvm-unit-tests can be used inside kvm to tests the correct delegation of misaligned exceptions. Upstream OpenSBI can be used. The tests can be run using the kselftest from series [4]. $ qemu-system-riscv64 \ -cpu rv64,trap-misaligned-access=true,v=true \ -M virt \ -m 1024M \ -bios fw_dynamic.bin \ -kernel Image ... # ./misaligned TAP version 13 1..23 # Starting 23 tests from 1 test cases. # RUN global.gp_load_lh ... # OK global.gp_load_lh ok 1 global.gp_load_lh # RUN global.gp_load_lhu ... # OK global.gp_load_lhu ok 2 global.gp_load_lhu # RUN global.gp_load_lw ... # OK global.gp_load_lw ok 3 global.gp_load_lw # RUN global.gp_load_lwu ... # OK global.gp_load_lwu ok 4 global.gp_load_lwu # RUN global.gp_load_ld ... # OK global.gp_load_ld ok 5 global.gp_load_ld # RUN global.gp_load_c_lw ... # OK global.gp_load_c_lw ok 6 global.gp_load_c_lw # RUN global.gp_load_c_ld ... # OK global.gp_load_c_ld ok 7 global.gp_load_c_ld # RUN global.gp_load_c_ldsp ... # OK global.gp_load_c_ldsp ok 8 global.gp_load_c_ldsp # RUN global.gp_load_sh ... # OK global.gp_load_sh ok 9 global.gp_load_sh # RUN global.gp_load_sw ... # OK global.gp_load_sw ok 10 global.gp_load_sw # RUN global.gp_load_sd ... # OK global.gp_load_sd ok 11 global.gp_load_sd # RUN global.gp_load_c_sw ... # OK global.gp_load_c_sw ok 12 global.gp_load_c_sw # RUN global.gp_load_c_sd ... # OK global.gp_load_c_sd ok 13 global.gp_load_c_sd # RUN global.gp_load_c_sdsp ... # OK global.gp_load_c_sdsp ok 14 global.gp_load_c_sdsp # RUN global.fpu_load_flw ... # OK global.fpu_load_flw ok 15 global.fpu_load_flw # RUN global.fpu_load_fld ... # OK global.fpu_load_fld ok 16 global.fpu_load_fld # RUN global.fpu_load_c_fld ... # OK global.fpu_load_c_fld ok 17 global.fpu_load_c_fld # RUN global.fpu_load_c_fldsp ... # OK global.fpu_load_c_fldsp ok 18 global.fpu_load_c_fldsp # RUN global.fpu_store_fsw ... # OK global.fpu_store_fsw ok 19 global.fpu_store_fsw # RUN global.fpu_store_fsd ... # OK global.fpu_store_fsd ok 20 global.fpu_store_fsd # RUN global.fpu_store_c_fsd ... # OK global.fpu_store_c_fsd ok 21 global.fpu_store_c_fsd # RUN global.fpu_store_c_fsdsp ... # OK global.fpu_store_c_fsdsp ok 22 global.fpu_store_c_fsdsp # RUN global.gen_sigbus ... [12797.988647] misaligned[618]: unhandled signal 7 code 0x1 at 0x0000000000014dc0 in misaligned[4dc0,10000+76000] [12797.988990] CPU: 0 UID: 0 PID: 618 Comm: misaligned Not tainted 6.13.0-rc6-00008-g4ec4468967c9-dirty #51 [12797.989169] Hardware name: riscv-virtio,qemu (DT) [12797.989264] epc : 0000000000014dc0 ra : 0000000000014d00 sp : 00007fffe165d100 [12797.989407] gp : 000000000008f6e8 tp : 0000000000095760 t0 : 0000000000000008 [12797.989544] t1 : 00000000000965d8 t2 : 000000000008e830 s0 : 00007fffe165d160 [12797.989692] s1 : 000000000000001a a0 : 0000000000000000 a1 : 0000000000000002 [12797.989831] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffffdeadbeef [12797.989964] a5 : 000000000008ef61 a6 : 626769735f6e0000 a7 : fffffffffffff000 [12797.990094] s2 : 0000000000000001 s3 : 00007fffe165d838 s4 : 00007fffe165d848 [12797.990238] s5 : 000000000000001a s6 : 0000000000010442 s7 : 0000000000010200 [12797.990391] s8 : 000000000000003a s9 : 0000000000094508 s10: 0000000000000000 [12797.990526] s11: 0000555567460668 t3 : 00007fffe165d070 t4 : 00000000000965d0 [12797.990656] t5 : fefefefefefefeff t6 : 0000000000000073 [12797.990756] status: 0000000200004020 badaddr: 000000000008ef61 cause: 0000000000000006 [12797.990911] Code: 8793 8791 3423 fcf4 3783 fc84 c737 dead 0713 eef7 (c398) 0001 # OK global.gen_sigbus ok 23 global.gen_sigbus # PASSED: 23 / 23 tests passed. # Totals: pass:23 fail:0 xfail:0 xpass:0 skip:0 error:0 With kvm-tools: # lkvm run -k sbi.flat -m 128 Info: # lkvm run -k sbi.flat -m 128 -c 1 --name guest-97 Info: Removed ghost socket file "/root/.lkvm//guest-97.sock". ########################################################################## # kvm-unit-tests ########################################################################## ... [test messages elided] PASS: sbi: fwft: FWFT extension probing no error PASS: sbi: fwft: get/set reserved feature 0x6 error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0x3fffffff error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0x80000000 error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0xbfffffff error == SBI_ERR_DENIED PASS: sbi: fwft: misaligned_deleg: Get misaligned deleg feature no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 0 PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 1 PASS: sbi: fwft: misaligned_deleg: Verify misaligned load exception trap in supervisor SUMMARY: 50 tests, 2 unexpected failures, 12 skipped This series is available at [5]. [Palmer: slighyt commit text modification, as SBI-3.0 is merged now. Also drop the KVM patches, as they're too late.] * b4-shazam-merge: riscv: misaligned: add a function to check misalign trap delegability riscv: misaligned: move emulated access uniformity check in a function riscv: misaligned: declare misaligned_access_speed under CONFIG_RISCV_MISALIGNED riscv: misaligned: use on_each_cpu() for scalar misaligned access probing riscv: misaligned: request misaligned exception from SBI riscv: sbi: add SBI FWFT extension calls riscv: sbi: add FWFT extension interface riscv: sbi: add new SBI error mappings riscv: sbi: remove useless parenthesis riscv: sbi: add Firmware Feature (FWFT) SBI extensions definitions Link: https://lore.kernel.org/r/20250523101932.1594077-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-05Merge tag 'riscv-mw2-6.16-rc1' of ↵Palmer Dabbelt
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/alexghiti/linux into for-next riscv patches for 6.16-rc1, part 2 * Performance improvements - Add support for vdso getrandom - Implement raid6 calculations using vectors - Introduce svinval tlb invalidation * Cleanup - A bunch of deduplication of the macros we use for manipulating instructions * Misc - Introduce a kunit test for kprobes - Add support for mseal as riscv fits the requirements (thanks to Lorenzo for making sure of that :)) [Palmer: There was a rebase between part 1 and part 2, so I've had to do some more git surgery here... at least two rounds of surgery...] * alex-pr-2: (866 commits) RISC-V: vDSO: Wire up getrandom() vDSO implementation riscv: enable mseal sysmap for RV64 raid6: Add RISC-V SIMD syndrome and recovery calculations riscv: mm: Add support for Svinval extension riscv: Add kprobes KUnit test riscv: kprobes: Remove duplication of RV_EXTRACT_ITYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_UTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_RD_REG riscv: kprobes: Remove duplication of RVC_EXTRACT_BTYPE_IMM riscv: kprobes: Remove duplication of RVC_EXTRACT_C2_RS1_REG riscv: kproves: Remove duplication of RVC_EXTRACT_JTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_BTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_RS1_REG riscv: kprobes: Remove duplication of RV_EXTRACT_JTYPE_IMM riscv: kprobes: Move branch_funct3 to insn.h riscv: kprobes: Move branch_rs2_idx to insn.h Linux 6.15-rc6 Input: xpad - fix xpad_device sorting Input: xpad - add support for several more controllers Input: xpad - fix Share button on Xbox One controllers ...
2025-06-04riscv: misaligned: add a function to check misalign trap delegabilityClément Léger
Checking for the delegability of the misaligned access trap is needed for the KVM FWFT extension implementation. Add a function to get the delegability of the misaligned trap exception. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20250523101932.1594077-11-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-04riscv: misaligned: move emulated access uniformity check in a functionClément Léger
Split the code that check for the uniformity of misaligned accesses performance on all cpus from check_unaligned_access_emulated_all_cpus() to its own function which will be used for delegation check. No functional changes intended. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20250523101932.1594077-10-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-04riscv: misaligned: declare misaligned_access_speed under CONFIG_RISCV_MISALIGNEDClément Léger
While misaligned_access_speed was defined in a file compile with CONFIG_RISCV_MISALIGNED, its definition was under CONFIG_RISCV_SCALAR_MISALIGNED. This resulted in compilation problems when using it in a file compiled with CONFIG_RISCV_MISALIGNED. Move the declaration under CONFIG_RISCV_MISALIGNED so that it can be used unconditionnally when compiled with that config and remove the check for that variable in traps_misaligned.c. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20250523101932.1594077-9-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-04riscv: misaligned: use on_each_cpu() for scalar misaligned access probingClément Léger
schedule_on_each_cpu() was used without any good reason while documented as very slow. This call was in the boot path, so better use on_each_cpu() for scalar misaligned checking. Vector misaligned check still needs to use schedule_on_each_cpu() since it requires irqs to be enabled but that's less of a problem since this code is ran in a kthread. Add a comment to explicit that. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20250523101932.1594077-8-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-04riscv: misaligned: request misaligned exception from SBIClément Léger
Now that the kernel can handle misaligned accesses in S-mode, request misaligned access exception delegation from SBI. This uses the FWFT SBI extension defined in SBI version 3.0. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20250523101932.1594077-7-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-05-08riscv: misaligned: use get_user() instead of __get_user()Clément Léger
Now that we can safely handle user memory accesses while in the misaligned access handlers, use get_user() instead of __get_user() to have user memory access checks. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20250422162324.956065-4-cleger@rivosinc.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-05-05riscv: misaligned: Add handling for ZCB instructionsNylon Chen
Add support for the Zcb extension's compressed half-word instructions (C.LHU, C.LH, and C.SH) in the RISC-V misaligned access trap handler. Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Nylon Chen <nylon.chen@sifive.com> Fixes: 956d705dd279 ("riscv: Unaligned load/store handling for M_MODE") Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20250411073850.3699180-2-nylon.chen@sifive.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-04-18riscv: misaligned: Add handling for ZCB instructionsNylon Chen
Add support for the Zcb extension's compressed half-word instructions (C.LHU, C.LH, and C.SH) in the RISC-V misaligned access trap handler. Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Nylon Chen <nylon.chen@sifive.com> Link: https://lore.kernel.org/r/20250411073850.3699180-2-nylon.chen@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-04-18riscv: misaligned: fix sleeping function called during misaligned access ↵Nylon Chen
handling Use copy_from_user_nofault() and copy_to_user_nofault() instead of copy_from/to_user functions in the misaligned access trap handlers. The following bug report was found when executing misaligned memory accesses: BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:162 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 115, name: two preempt_count: 0, expected: 0 CPU: 0 UID: 0 PID: 115 Comm: two Not tainted 6.14.0-rc5 #24 Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff800160ea>] dump_backtrace+0x1c/0x24 [<ffffffff80002304>] show_stack+0x28/0x34 [<ffffffff80010fae>] dump_stack_lvl+0x4a/0x68 [<ffffffff80010fe0>] dump_stack+0x14/0x1c [<ffffffff8004e44e>] __might_resched+0xfa/0x104 [<ffffffff8004e496>] __might_sleep+0x3e/0x62 [<ffffffff801963c4>] __might_fault+0x1c/0x24 [<ffffffff80425352>] _copy_from_user+0x28/0xaa [<ffffffff8000296c>] handle_misaligned_store+0x204/0x254 [<ffffffff809eae82>] do_trap_store_misaligned+0x24/0xee [<ffffffff809f4f1a>] handle_exception+0x146/0x152 Fixes: b686ecdeacf6 ("riscv: misaligned: Restrict user access to kernel memory") Fixes: 441381506ba7 ("riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code") Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Nylon Chen <nylon.chen@sifive.com> Link: https://lore.kernel.org/r/20250411073850.3699180-3-nylon.chen@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-03-19riscv: Fix check_unaligned_access_all_cpusAndrew Jones
check_vector_unaligned_access_emulated_all_cpus(), like its name suggests, will return true when all cpus emulate unaligned vector accesses. If the function returned false it may have been because vector isn't supported at all (!has_vector()) or because at least one cpu doesn't emulate unaligned vector accesses. Since false may be returned for two cases, checking for it isn't sufficient when attempting to determine if we should proceed with the vector speed check. Move the !has_vector() functionality to check_unaligned_access_all_cpus() in order for check_vector_unaligned_access_emulated_all_cpus() to return false for a single case. Fixes: e7c9d66e313b ("RISC-V: Report vector unaligned access speed hwprobe") Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20250304120014.143628-13-ajones@ventanamicro.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-03-19riscv: Annotate unaligned access init functionsAndrew Jones
Several functions used in unaligned access probing are only run at init time. Annotate them appropriately. Fixes: f413aae96cda ("riscv: Set unaligned access speed at compile time") Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20250304120014.143628-11-ajones@ventanamicro.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2024-11-27Merge tag 'riscv-for-linus-6.13-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-v updates from Palmer Dabbelt: - Support for pointer masking in userspace - Support for probing vector misaligned access performance - Support for qspinlock on systems with Zacas and Zabha * tag 'riscv-for-linus-6.13-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (38 commits) RISC-V: Remove unnecessary include from compat.h riscv: Fix default misaligned access trap riscv: Add qspinlock support dt-bindings: riscv: Add Ziccrse ISA extension description riscv: Add ISA extension parsing for Ziccrse asm-generic: ticket-lock: Add separate ticket-lock.h asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock riscv: Implement xchg8/16() using Zabha riscv: Implement arch_cmpxchg128() using Zacas riscv: Improve zacas fully-ordered cmpxchg() riscv: Implement cmpxchg8/16() using Zabha dt-bindings: riscv: Add Zabha ISA extension description riscv: Implement cmpxchg32/64() using Zacas riscv: Do not fail to build on byte/halfword operations with Zawrs riscv: Move cpufeature.h macros into their own header KVM: riscv: selftests: Add Smnpm and Ssnpm to get-reg-list test RISC-V: KVM: Allow Smnpm and Ssnpm extensions for guests riscv: hwprobe: Export the Supm ISA extension riscv: selftests: Add a pointer masking test riscv: Allow ptrace control of the tagged address ABI ...
2024-10-25riscv: Remove duplicated GET_RMChunyan Zhang
The macro GET_RM defined twice in this file, one can be removed. Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Fixes: 956d705dd279 ("riscv: Unaligned load/store handling for M_MODE") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20241008094141.549248-3-zhangchunyan@iscas.ac.cn Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-18RISC-V: Detect unaligned vector accesses supportedJesse Taube
Run an unaligned vector access to test if the system supports vector unaligned access. Add the result to a new key in hwprobe. This is useful for usermode to know if vector misaligned accesses are supported and if they are faster or slower than equivalent byte accesses. Signed-off-by: Jesse Taube <jesse@rivosinc.com> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20241017-jesse_unaligned_vector-v10-4-5b33500160f8@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-18RISC-V: Check scalar unaligned access on all CPUsJesse Taube
Originally, the check_unaligned_access_emulated_all_cpus function only checked the boot hart. This fixes the function to check all harts. Fixes: 71c54b3d169d ("riscv: report misaligned accesses emulation to hwprobe") Signed-off-by: Jesse Taube <jesse@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20241017-jesse_unaligned_vector-v10-1-5b33500160f8@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-31riscv: misaligned: Restrict user access to kernel memorySamuel Holland
raw_copy_{to,from}_user() do not call access_ok(), so this code allowed userspace to access any virtual memory address. Cc: stable@vger.kernel.org Fixes: 7c83232161f6 ("riscv: add support for misaligned trap handling in S-mode") Fixes: 441381506ba7 ("riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240815005714.1163136-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14RISC-V: hwprobe: Add SCALAR to misaligned perf definesEvan Green
In preparation for misaligned vector performance hwprobe keys, rename the hwprobe key values associated with misaligned scalar accesses to include the term SCALAR. Leave the old defines in place to maintain source compatibility. This change is intended to be a functional no-op. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240809214444.3257596-3-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-28riscv: misaligned: remove CONFIG_RISCV_M_MODE specific codeClément Léger
While reworking code to fix sparse errors, it appears that the RISCV_M_MODE specific could actually be removed and use the one for normal mode. Even though RISCV_M_MODE can do direct user memory access, using the user uaccess helpers is also going to work. Since there is no need anymore for specific accessors (load_u8()/store_u8()), we can directly use memcpy()/copy_{to/from}_user() and get rid of the copy loop entirely. __read_insn() is also fixed to use an unsigned long instead of a pointer which was cast in __user address space. The insn_addr parameter is now cast from unsigned lnog to the correct address space directly. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240206154104.896809-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-13riscv: Set unaligned access speed at compile timeCharlie Jenkins
Introduce Kconfig options to set the kernel unaligned access support. These options provide a non-portable alternative to the runtime unaligned access probe. To support this, the unaligned access probing code is moved into it's own file and gated behind a new RISCV_PROBE_UNALIGNED_ACCESS_SUPPORT option. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240308-disable_misaligned_probe_config-v9-4-a388770ba0ce@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-13riscv: Decouple emulated unaligned accesses from access speedCharlie Jenkins
Detecting if a system traps into the kernel on an unaligned access can be performed separately from checking the speed of unaligned accesses. This decoupling will make it possible to selectively enable or disable each of these checks. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240308-disable_misaligned_probe_config-v9-3-a388770ba0ce@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-13riscv: Only check online cpus for emulated accessesCharlie Jenkins
The unaligned access checker only sets valid values for online cpus. Check for these values on online cpus rather than on present cpus. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Fixes: 71c54b3d169d ("riscv: report misaligned accesses emulation to hwprobe") Tested-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240308-disable_misaligned_probe_config-v9-2-a388770ba0ce@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09Merge remote-tracking branch 'palmer/fixes' into for-nextPalmer Dabbelt
I don't usually merge these in, but I missed sending a PR due to the holidays. * palmer/fixes: riscv: Fix set_direct_map_default_noflush() to reset _PAGE_EXEC riscv: Fix module_alloc() that did not reset the linear mapping permissions riscv: Fix wrong usage of lm_alias() when splitting a huge linear mapping riscv: Check if the code to patch lies in the exit section riscv: errata: andes: Probe for IOCP only once in boot stage riscv: Fix SMP when shadow call stacks are enabled dt-bindings: perf: riscv,pmu: drop unneeded quotes riscv: fix misaligned access handling of C.SWSP and C.SDSP RISC-V: hwprobe: Always use u64 for extension bits Support rv32 ULEB128 test riscv: Correct type casting in module loading riscv: Safely remove entries from relocation list Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09riscv: fix __user annotation in traps_misaligned.cBen Dooks
The instruction reading code can read from either user or kernel addresses and thus the use of __user on pointers to instructions depends on which context. Fix a few sparse warnings by using __user for user-accesses and remove it when not. Fixes: arch/riscv/kernel/traps_misaligned.c:361:21: warning: dereference of noderef expression arch/riscv/kernel/traps_misaligned.c:373:21: warning: dereference of noderef expression arch/riscv/kernel/traps_misaligned.c:381:21: warning: dereference of noderef expression arch/riscv/kernel/traps_misaligned.c:322:24: warning: incorrect type in initializer (different address spaces) arch/riscv/kernel/traps_misaligned.c:322:24: expected unsigned char const [noderef] __user *__gu_ptr arch/riscv/kernel/traps_misaligned.c:322:24: got unsigned char const [usertype] *addr arch/riscv/kernel/traps_misaligned.c:361:21: warning: dereference of noderef expression arch/riscv/kernel/traps_misaligned.c:373:21: warning: dereference of noderef expression arch/riscv/kernel/traps_misaligned.c:381:21: warning: dereference of noderef expression arch/riscv/kernel/traps_misaligned.c:332:24: warning: incorrect type in initializer (different address spaces) arch/riscv/kernel/traps_misaligned.c:332:24: expected unsigned char [noderef] __user *__gu_ptr arch/riscv/kernel/traps_misaligned.c:332:24: got unsigned char [usertype] *addr Fixes: 7c83232161f60 ("riscv: add support for misaligned trap handling in S-mode") Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Link: https://lore.kernel.org/r/20231123141617.259591-1-ben.dooks@codethink.co.uk Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-06riscv: fix misaligned access handling of C.SWSP and C.SDSPClément Léger
This is a backport of a fix that was done in OpenSBI: ec0559eb315b ("lib: sbi_misaligned_ldst: Fix handling of C.SWSP and C.SDSP"). Unlike C.LWSP/C.LDSP, these encodings can be used with the zero register, so checking that the rs2 field is non-zero is unnecessary. Additionally, the previous check was incorrect since it was checking the immediate field of the instruction instead of the rs2 field. Fixes: 956d705dd279 ("riscv: Unaligned load/store handling for M_MODE") Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231103090223.702340-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-07RISC-V: Remove __init on unaligned_emulation_finish()Evan Green
This function shouldn't be __init, since it's called during hotplug. The warning says it well enough: WARNING: modpost: vmlinux: section mismatch in reference: check_unaligned_access_all_cpus+0x13a (section: .text) -> unaligned_emulation_finish (section: .init.text) Signed-off-by: Evan Green <evan@rivosinc.com> Fixes: 71c54b3d169d ("riscv: report misaligned accesses emulation to hwprobe") Link: https://lore.kernel.org/r/20231106231105.3141413-1-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: add support for PR_SET_UNALIGN and PR_GET_UNALIGNClément Léger
Now that trap support is ready to handle misalignment errors in S-mode, allow the user to control the behavior of misaligned accesses using prctl(PR_SET_UNALIGN). Add an align_ctl flag in thread_struct which will be used to determine if we should SIGBUS the process or not on such fault. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-9-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: report misaligned accesses emulation to hwprobeClément Léger
hwprobe provides a way to report if misaligned access are emulated. In order to correctly populate that feature, we can check if it actually traps when doing a misaligned access. This can be checked using an exception table entry which will actually be used when a misaligned access is done from kernel mode. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-8-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: add support for sysctl unaligned_enabled controlClément Léger
This sysctl tuning option allows the user to disable misaligned access handling globally on the system. This will also be used by misaligned detection code to temporarily disable misaligned access handling. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-6-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: add floating point insn support to misaligned access emulationClément Léger
This support is partially based of openSBI misaligned emulation floating point instruction support. It provides support for the existing floating point instructions (both for 32/64 bits as well as compressed ones). Since floating point registers are not part of the pt_regs struct, we need to modify them directly using some assembly. We also dirty the pt_regs status in case we modify them to be sure context switch will save FP state. With this support, Linux is on par with openSBI support. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-5-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: report perf event for misaligned faultClément Léger
Add missing calls to account for misaligned fault event using perf_sw_event(). Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-4-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: add support for misaligned trap handling in S-modeClément Léger
Misalignment trap handling is only supported for M-mode and uses direct accesses to user memory. In S-mode, when handling usermode fault, this requires to use the get_user()/put_user() accessors. Implement load_u8(), store_u8() and get_insn() using these accessors for userspace and direct text access for kernel. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-3-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: remove unused functions in traps_misaligned.cClément Léger
Replace macros by the only two function calls that are done from this file, store_u8() and load_u8(). Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-2-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-11riscv: traps_misaligned: do not duplicate stringifyKrzysztof Kozlowski
Use existing stringify macro from the kernel headers. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20220623112905.253157-1-krzysztof.kozlowski@linaro.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2020-04-03riscv: Unaligned load/store handling for M_MODEDamien Le Moal
Add handlers for unaligned load and store traps that may be generated by applications. Code heavily inspired from the OpenSBI project. Handling of the unaligned access traps is suitable for applications compiled with or without compressed instructions and is independent of the kernel CONFIG_RISCV_ISA_C option value. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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