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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 97 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29 07:18:00 -07:00
/* SPDX-License-Identifier: GPL-2.0-only */
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
/*
* Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*/
#ifndef _ASM_RISCV_THREAD_INFO_H
#define _ASM_RISCV_THREAD_INFO_H
#include <asm/page.h>
#include <linux/const.h>
riscv: enable HAVE_ARCH_STACKLEAK Add support for the stackleak feature. Whenever the kernel returns to user space the kernel stack is filled with a poison value. At the same time, disables the plugin in EFI stub code because EFI stub is out of scope for the protection. Tested on qemu and milkv duo: / # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT [ 38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING [ 38.678448] lkdtm: stackleak stack usage: [ 38.678448] high offset: 288 bytes [ 38.678448] current: 496 bytes [ 38.678448] lowest: 1328 bytes [ 38.678448] tracked: 1328 bytes [ 38.678448] untracked: 448 bytes [ 38.678448] poisoned: 14312 bytes [ 38.678448] low offset: 8 bytes [ 38.689887] lkdtm: OK: the rest of the thread stack is properly erased Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-24 07:53:16 +08:00
#include <linux/sizes.h>
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
/* thread information allocation */
riscv: Fix kernel stack size when KASAN is enabled We use Kconfig to select the kernel stack size, doubling the default size if KASAN is enabled. But that actually only works if KASAN is selected from the beginning, meaning that if KASAN config is added later (for example using menuconfig), CONFIG_THREAD_SIZE_ORDER won't be updated, keeping the default size, which is not enough for KASAN as reported in [1]. So fix this by moving the logic to compute the right kernel stack into a header. Fixes: a7555f6b62e7 ("riscv: stack: Add config of thread stack size") Reported-by: syzbot+ba9eac24453387a9d502@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000eb301906222aadc2@google.com/ [1] Cc: stable@vger.kernel.org Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240917150328.59831-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-17 17:03:28 +02:00
#ifdef CONFIG_KASAN
#define KASAN_STACK_ORDER 1
#else
#define KASAN_STACK_ORDER 0
#endif
#define THREAD_SIZE_ORDER (CONFIG_THREAD_SIZE_ORDER + KASAN_STACK_ORDER)
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
riscv: add VMAP_STACK overflow detection This patch adds stack overflow detection to riscv, usable when CONFIG_VMAP_STACK=y. Overflow is detected in kernel exception entry(kernel/entry.S), if the kernel stack is overflow and been detected, the overflow handler is invoked on a per-cpu overflow stack. This approach preserves GPRs and the original exception information. The overflow detect is performed before any attempt is made to access the stack and the principle of stack overflow detection: kernel stacks are aligned to double their size, enabling overflow to be detected with a single bit test. For example, a 16K stack is aligned to 32K, ensuring that bit 14 of the SP must be zero. On an overflow (or underflow), this bit is flipped. Thus, overflow (of less than the size of the stack) can be detected by testing whether this bit is set. This gives us a useful error message on stack overflow, as can be trigger with the LKDTM overflow test: [ 388.053267] lkdtm: Performing direct entry EXHAUST_STACK [ 388.053663] lkdtm: Calling function with 1024 frame size to depth 32 ... [ 388.054016] lkdtm: loop 32/32 ... [ 388.054186] lkdtm: loop 31/32 ... [ 388.054491] lkdtm: loop 30/32 ... [ 388.054672] lkdtm: loop 29/32 ... [ 388.054859] lkdtm: loop 28/32 ... [ 388.055010] lkdtm: loop 27/32 ... [ 388.055163] lkdtm: loop 26/32 ... [ 388.055309] lkdtm: loop 25/32 ... [ 388.055481] lkdtm: loop 24/32 ... [ 388.055653] lkdtm: loop 23/32 ... [ 388.055837] lkdtm: loop 22/32 ... [ 388.056015] lkdtm: loop 21/32 ... [ 388.056188] lkdtm: loop 20/32 ... [ 388.058145] Insufficient stack space to handle exception! [ 388.058153] Task stack: [0xffffffd014260000..0xffffffd014264000] [ 388.058160] Overflow stack: [0xffffffe1f8d2c220..0xffffffe1f8d2d220] [ 388.058168] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90 [ 388.058175] Hardware name: riscv-virtio,qemu (DT) [ 388.058187] epc : number+0x32/0x2c0 [ 388.058247] ra : vsnprintf+0x2ae/0x3f0 [ 388.058255] epc : ffffffe0002d38f6 ra : ffffffe0002d814e sp : ffffffd01425ffc0 [ 388.058263] gp : ffffffe0012e4010 tp : ffffffe08014da00 t0 : ffffffd0142606e8 [ 388.058271] t1 : 0000000000000000 t2 : 0000000000000000 s0 : ffffffd014260070 [ 388.058303] s1 : ffffffd014260158 a0 : ffffffd01426015e a1 : ffffffd014260158 [ 388.058311] a2 : 0000000000000013 a3 : ffff0a01ffffff10 a4 : ffffffe000c398e0 [ 388.058319] a5 : 511b02ec65f3e300 a6 : 0000000000a1749a a7 : 0000000000000000 [ 388.058327] s2 : ffffffff000000ff s3 : 00000000ffff0a01 s4 : ffffffe0012e50a8 [ 388.058335] s5 : 0000000000ffff0a s6 : ffffffe0012e50a8 s7 : ffffffe000da1cc0 [ 388.058343] s8 : ffffffffffffffff s9 : ffffffd0142602b0 s10: ffffffd0142602a8 [ 388.058351] s11: ffffffd01426015e t3 : 00000000000f0000 t4 : ffffffffffffffff [ 388.058359] t5 : 000000000000002f t6 : ffffffd014260158 [ 388.058366] status: 0000000000000100 badaddr: ffffffd01425fff8 cause: 000000000000000f [ 388.058374] Kernel panic - not syncing: Kernel stack overflow [ 388.058381] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90 [ 388.058387] Hardware name: riscv-virtio,qemu (DT) [ 388.058393] Call Trace: [ 388.058400] [<ffffffe000004944>] walk_stackframe+0x0/0xce [ 388.058406] [<ffffffe0006f0b28>] dump_backtrace+0x38/0x46 [ 388.058412] [<ffffffe0006f0b46>] show_stack+0x10/0x18 [ 388.058418] [<ffffffe0006f3690>] dump_stack+0x74/0x8e [ 388.058424] [<ffffffe0006f0d52>] panic+0xfc/0x2b2 [ 388.058430] [<ffffffe0006f0acc>] print_trace_address+0x0/0x24 [ 388.058436] [<ffffffe0002d814e>] vsnprintf+0x2ae/0x3f0 [ 388.058956] SMP: stopping secondary CPUs Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-21 11:28:55 +08:00
/*
* By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
* checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
* assembly.
*/
#ifdef CONFIG_VMAP_STACK
#define THREAD_ALIGN (2 * THREAD_SIZE)
#else
#define THREAD_ALIGN THREAD_SIZE
#endif
#define THREAD_SHIFT (PAGE_SHIFT + THREAD_SIZE_ORDER)
#define OVERFLOW_STACK_SIZE SZ_4K
riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK Add independent irq stacks for percpu to prevent kernel stack overflows. It is also compatible with VMAP_STACK by arch_alloc_vmap_stack. Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20230614013018.2168426-2-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-13 21:30:16 -04:00
#define IRQ_STACK_SIZE THREAD_SIZE
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#include <asm/csr.h>
/*
* low level task data that entry.S needs immediate access to
* - this struct should fit entirely inside of one cache line
* - if the members of this struct changes, the assembly constants
* in asm-offsets.c must be updated accordingly
* - thread_info is included in task_struct at an offset of 0. This means that
* tp points to both thread_info and task_struct.
*/
struct thread_info {
unsigned long flags; /* low level flags */
int preempt_count; /* 0=>preemptible, <0=>BUG */
/*
* These stack pointers are overwritten on every system call or
* exception. SP is also saved to the stack it can be recovered when
* overwritten.
*/
long kernel_sp; /* Kernel stack pointer */
long user_sp; /* User stack pointer */
int cpu;
riscv: entry: Convert to generic entry This patch converts riscv to use the generic entry infrastructure from kernel/entry/*. The generic entry makes maintainers' work easier and codes more elegant. Here are the changes: - More clear entry.S with handle_exception and ret_from_exception - Get rid of complex custom signal implementation - Move syscall procedure from assembly to C, which is much more readable. - Connect ret_from_fork & ret_from_kernel_thread to generic entry. - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode - Use the standard preemption code instead of custom Suggested-by: Huacai Chen <chenhuacai@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Yipeng Zou <zouyipeng@huawei.com> Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Link: https://lore.kernel.org/r/20230222033021.983168-5-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-21 22:30:18 -05:00
unsigned long syscall_work; /* SYSCALL_WORK_ flags */
riscv: Implement Shadow Call Stack Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the compiler injects instructions to all non-leaf C functions to store the return address to the shadow stack and unconditionally load it again before returning, which makes it harder to corrupt the return address through a stack overflow, for example. The active shadow call stack pointer is stored in the gp register, which makes SCS incompatible with gp relaxation. Use --no-relax-gp to ensure gp relaxation is disabled and disable global pointer loading. Add SCS pointers to struct thread_info, implement SCS initialization, and task switching Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-27 22:48:02 +00:00
#ifdef CONFIG_SHADOW_CALL_STACK
void *scs_base;
void *scs_sp;
#endif
riscv: Stop emitting preventive sfence.vma for new vmalloc mappings In 6.5, we removed the vmalloc fault path because that can't work (see [1] [2]). Then in order to make sure that new page table entries were seen by the page table walker, we had to preventively emit a sfence.vma on all harts [3] but this solution is very costly since it relies on IPI. And even there, we could end up in a loop of vmalloc faults if a vmalloc allocation is done in the IPI path (for example if it is traced, see [4]), which could result in a kernel stack overflow. Those preventive sfence.vma needed to be emitted because: - if the uarch caches invalid entries, the new mapping may not be observed by the page table walker and an invalidation may be needed. - if the uarch does not cache invalid entries, a reordered access could "miss" the new mapping and traps: in that case, we would actually only need to retry the access, no sfence.vma is required. So this patch removes those preventive sfence.vma and actually handles the possible (and unlikely) exceptions. And since the kernel stacks mappings lie in the vmalloc area, this handling must be done very early when the trap is taken, at the very beginning of handle_exception: this also rules out the vmalloc allocations in the fault path. Link: https://lore.kernel.org/linux-riscv/20230531093817.665799-1-bjorn@kernel.org/ [1] Link: https://lore.kernel.org/linux-riscv/20230801090927.2018653-1-dylan@andestech.com [2] Link: https://lore.kernel.org/linux-riscv/20230725132246.817726-1-alexghiti@rivosinc.com/ [3] Link: https://lore.kernel.org/lkml/20200508144043.13893-1-joro@8bytes.org/ [4] Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/20240717060125.139416-4-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-17 08:01:24 +02:00
#ifdef CONFIG_64BIT
/*
* Used in handle_exception() to save a0, a1 and a2 before knowing if we
* can access the kernel stack.
*/
unsigned long a0, a1, a2;
#endif
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
};
riscv: Implement Shadow Call Stack Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the compiler injects instructions to all non-leaf C functions to store the return address to the shadow stack and unconditionally load it again before returning, which makes it harder to corrupt the return address through a stack overflow, for example. The active shadow call stack pointer is stored in the gp register, which makes SCS incompatible with gp relaxation. Use --no-relax-gp to ensure gp relaxation is disabled and disable global pointer loading. Add SCS pointers to struct thread_info, implement SCS initialization, and task switching Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-27 22:48:02 +00:00
#ifdef CONFIG_SHADOW_CALL_STACK
#define INIT_SCS \
.scs_base = init_shadow_call_stack, \
.scs_sp = init_shadow_call_stack,
#else
#define INIT_SCS
#endif
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
/*
* macros/functions for gaining access to the thread information structure
*
* preempt_count needs to be 1 initially, until the scheduler is functional.
*/
#define INIT_THREAD_INFO(tsk) \
{ \
.flags = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
riscv: Implement Shadow Call Stack Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the compiler injects instructions to all non-leaf C functions to store the return address to the shadow stack and unconditionally load it again before returning, which makes it harder to corrupt the return address through a stack overflow, for example. The active shadow call stack pointer is stored in the gp register, which makes SCS incompatible with gp relaxation. Use --no-relax-gp to ensure gp relaxation is disabled and disable global pointer loading. Add SCS pointers to struct thread_info, implement SCS initialization, and task switching Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-27 22:48:02 +00:00
INIT_SCS \
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
}
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
void arch_release_task_struct(struct task_struct *tsk);
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
#endif /* !__ASSEMBLY__ */
/*
* thread information flags
* - these are process state flags that various assembly files may need to
* access
* - pending work-to-be-done flags are in lowest half-word
* - other flags in upper half-word(s)
*/
riscv: add PREEMPT_LAZY support riscv has switched to GENERIC_ENTRY, so adding PREEMPT_LAZY is as simple as adding TIF_NEED_RESCHED_LAZY related definitions and enabling ARCH_HAS_PREEMPT_LAZY. [bigeasy: Replace old PREEMPT_AUTO bits with new PREEMPT_LAZY ] Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lkml.kernel.org/r/20241021151257.102296-4-bigeasy@linutronix.de
2024-10-21 17:08:42 +02:00
#define TIF_NEED_RESCHED 0 /* rescheduling necessary */
#define TIF_NEED_RESCHED_LAZY 1 /* Lazy rescheduling needed */
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_SIGPENDING 3 /* signal pending */
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
#define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */
#define TIF_MEMDIE 5 /* is terminating due to OOM killer */
riscv: add support for TIF_NOTIFY_SIGNAL Wire up TIF_NOTIFY_SIGNAL handling for riscv. Cc: linux-riscv@lists.infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 14:29:17 -06:00
#define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */
riscv: Add uprobes supported This patch adds support for uprobes on riscv architecture. Just like kprobe, it support single-step and simulate instructions. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-12-17 16:01:44 +00:00
#define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */
riscv: compat: Add basic compat data type implementation Implement riscv asm/compat.h for struct compat_xxx, is_compat_task, compat_user_regset, regset convert. The rv64 compat.h has inherited most of the structs from the generic one. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Tested-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20220405071314.3225832-10-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-04-05 15:13:03 +08:00
#define TIF_32BIT 11 /* compat-mode 32bit process */
riscv: sched: defer restoring Vector context for user User will use its Vector registers only after the kernel really returns to the userspace. So we can delay restoring Vector registers as long as we are still running in kernel mode. So, add a thread flag to indicates the need of restoring Vector and do the restore at the last arch-specific exit-to-user hook. This save the context restoring cost when we switch over multiple processes that run V in kernel mode. For example, if the kernel performs a context swicth from A->B->C, and returns to C's userspace, then there is no need to restore B's V-register. Besides, this also prevents us from repeatedly restoring V context when executing kernel-mode Vector multiple times. The cost of this is that we must disable preemption and mark vector as busy during vstate_{save,restore}. Because then the V context will not get restored back immediately when a trap-causing context switch happens in the middle of vstate_{save,restore}. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-5-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:23 +00:00
#define TIF_RISCV_V_DEFER_RESTORE 12 /* restore Vector before returing to user */
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
riscv: add PREEMPT_LAZY support riscv has switched to GENERIC_ENTRY, so adding PREEMPT_LAZY is as simple as adding TIF_NEED_RESCHED_LAZY related definitions and enabling ARCH_HAS_PREEMPT_LAZY. [bigeasy: Replace old PREEMPT_AUTO bits with new PREEMPT_LAZY ] Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lkml.kernel.org/r/20241021151257.102296-4-bigeasy@linutronix.de
2024-10-21 17:08:42 +02:00
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
riscv: add support for TIF_NOTIFY_SIGNAL Wire up TIF_NOTIFY_SIGNAL handling for riscv. Cc: linux-riscv@lists.infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 14:29:17 -06:00
#define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL)
riscv: Add uprobes supported This patch adds support for uprobes on riscv architecture. Just like kprobe, it support single-step and simulate instructions. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-12-17 16:01:44 +00:00
#define _TIF_UPROBE (1 << TIF_UPROBE)
riscv: sched: defer restoring Vector context for user User will use its Vector registers only after the kernel really returns to the userspace. So we can delay restoring Vector registers as long as we are still running in kernel mode. So, add a thread flag to indicates the need of restoring Vector and do the restore at the last arch-specific exit-to-user hook. This save the context restoring cost when we switch over multiple processes that run V in kernel mode. For example, if the kernel performs a context swicth from A->B->C, and returns to C's userspace, then there is no need to restore B's V-register. Besides, this also prevents us from repeatedly restoring V context when executing kernel-mode Vector multiple times. The cost of this is that we must disable preemption and mark vector as busy during vstate_{save,restore}. Because then the V context will not get restored back immediately when a trap-causing context switch happens in the middle of vstate_{save,restore}. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-5-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:23 +00:00
#define _TIF_RISCV_V_DEFER_RESTORE (1 << TIF_RISCV_V_DEFER_RESTORE)
RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:04:30 -07:00
#endif /* _ASM_RISCV_THREAD_INFO_H */
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