[RFC PATCH v2 19/31] kvx: Add process management

Add process management support for kvx, including: thread info definition, context switch and process tracing. Co-developed-by: Clement Leger <clement(a)clement-leger.fr&gt; Signed-off-by: Clement Leger <clement(a)clement-leger.fr&gt; Co-developed-by: Guillaume Thouvenin <gthouvenin(a)kalray.eu&gt; Signed-off-by: Guillaume Thouvenin <gthouvenin(a)kalray.eu&gt; Co-developed-by: Julian Vetter <jvetter(a)kalray.eu&gt; Signed-off-by: Julian Vetter <jvetter(a)kalray.eu&gt; Co-developed-by: Marius Gligor <mgligor(a)kalray.eu&gt; Signed-off-by: Marius Gligor <mgligor(a)kalray.eu&gt; Co-developed-by: Vincent Chardon <vincent.chardon(a)elsys-design.com&gt; Signed-off-by: Vincent Chardon <vincent.chardon(a)elsys-design.com&gt; Co-developed-by: Yann Sionneau <ysionneau(a)kalray.eu&gt; Signed-off-by: Yann Sionneau <ysionneau(a)kalray.eu&gt; --- Notes: V1 -> V2: no change arch/kvx/include/asm/current.h | 22 +++ arch/kvx/include/asm/ptrace.h | 217 +++++++++++++++++++++++ arch/kvx/include/asm/switch_to.h | 21 +++ arch/kvx/include/asm/thread_info.h | 78 ++++++++ arch/kvx/include/uapi/asm/ptrace.h | 114 ++++++++++++ arch/kvx/kernel/process.c | 203 +++++++++++++++++++++ arch/kvx/kernel/ptrace.c | 276 +++++++++++++++++++++++++++++ arch/kvx/kernel/stacktrace.c | 173 ++++++++++++++++++ 8 files changed, 1104 insertions(+) create mode 100644 arch/kvx/include/asm/current.h create mode 100644 arch/kvx/include/asm/ptrace.h create mode 100644 arch/kvx/include/asm/switch_to.h create mode 100644 arch/kvx/include/asm/thread_info.h create mode 100644 arch/kvx/include/uapi/asm/ptrace.h create mode 100644 arch/kvx/kernel/process.c create mode 100644 arch/kvx/kernel/ptrace.c create mode 100644 arch/kvx/kernel/stacktrace.c diff --git a/arch/kvx/include/asm/current.h b/arch/kvx/include/asm/current.h new file mode 100644 index 000000000000..b5fd0f076ec9 --- /dev/null +++ b/arch/kvx/include/asm/current.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + */ + +#ifndef _ASM_KVX_CURRENT_H +#define _ASM_KVX_CURRENT_H + +#include <asm/percpu.h> +#include <asm/sfr.h> + +struct task_struct; + +static __always_inline struct task_struct *get_current(void) +{ + return (struct task_struct *) kvx_sfr_get(SR); +} + +#define current get_current() + +#endif /* _ASM_KVX_CURRENT_H */ diff --git a/arch/kvx/include/asm/ptrace.h b/arch/kvx/include/asm/ptrace.h new file mode 100644 index 000000000000..d1b1e0975d9e --- /dev/null +++ b/arch/kvx/include/asm/ptrace.h @@ -0,0 +1,217 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + * Marius Gligor + * Yann Sionneau + */ + +#ifndef _ASM_KVX_PTRACE_H +#define _ASM_KVX_PTRACE_H + +#include <asm/types.h> +#include <asm/sfr.h> +#include <uapi/asm/ptrace.h> + +#define GPR_COUNT 64 +#define SFR_COUNT 9 +#define VIRT_COUNT 1 + +#define ES_SYSCALL 0x3 + +#define KVX_HW_BREAKPOINT_COUNT 2 +#define KVX_HW_WATCHPOINT_COUNT 1 + +#define REG_SIZE sizeof(u64) + +/** + * When updating pt_regs structure, this size must be updated. + * This is the expected size of the pt_regs struct. + * It ensures the structure layout from gcc is the same as the one we + * expect in order to do packed load (load/store octuple) in assembly. + * Conclusion: never put sizeof(pt_regs) in here or we lose this check + * (build time check done in asm-offsets.c via BUILD_BUG_ON) + */ +#define PT_REGS_STRUCT_EXPECTED_SIZE \ + ((GPR_COUNT + SFR_COUNT + VIRT_COUNT) * REG_SIZE + \ + 2 * REG_SIZE) /* Padding for stack alignment */ + +/** + * Saved register structure. Note that we should save only the necessary + * registers. + * When you modify it, please read carefully the comment above. + * Moreover, you will need to modify user_pt_regs to match the beginning + * of this struct 1:1 + */ +struct pt_regs { + union { + struct user_pt_regs user_regs; + struct { + /* GPR */ + uint64_t r0; + uint64_t r1; + uint64_t r2; + uint64_t r3; + uint64_t r4; + uint64_t r5; + uint64_t r6; + uint64_t r7; + uint64_t r8; + uint64_t r9; + uint64_t r10; + uint64_t r11; + union { + uint64_t r12; + uint64_t sp; + }; + union { + uint64_t r13; + uint64_t tp; + }; + union { + uint64_t r14; + uint64_t fp; + }; + uint64_t r15; + uint64_t r16; + uint64_t r17; + uint64_t r18; + uint64_t r19; + uint64_t r20; + uint64_t r21; + uint64_t r22; + uint64_t r23; + uint64_t r24; + uint64_t r25; + uint64_t r26; + uint64_t r27; + uint64_t r28; + uint64_t r29; + uint64_t r30; + uint64_t r31; + uint64_t r32; + uint64_t r33; + uint64_t r34; + uint64_t r35; + uint64_t r36; + uint64_t r37; + uint64_t r38; + uint64_t r39; + uint64_t r40; + uint64_t r41; + uint64_t r42; + uint64_t r43; + uint64_t r44; + uint64_t r45; + uint64_t r46; + uint64_t r47; + uint64_t r48; + uint64_t r49; + uint64_t r50; + uint64_t r51; + uint64_t r52; + uint64_t r53; + uint64_t r54; + uint64_t r55; + uint64_t r56; + uint64_t r57; + uint64_t r58; + uint64_t r59; + uint64_t r60; + uint64_t r61; + uint64_t r62; + uint64_t r63; + + /* SFR */ + uint64_t lc; + uint64_t le; + uint64_t ls; + uint64_t ra; + + uint64_t cs; + uint64_t spc; + }; + }; + uint64_t sps; + uint64_t es; + + uint64_t ilr; + + /* "Virtual" registers */ + uint64_t orig_r0; + + /* Padding for stack alignment (see STACK_ALIGN) */ + uint64_t padding[2]; + + /** + * If you add some fields, please read carefully the comment for + * PT_REGS_STRUCT_EXPECTED_SIZE. + */ +}; + +#define pl(__reg) kvx_sfr_field_val(__reg, PS, PL) + +#define MODE_KERNEL 0 +#define MODE_USER 1 + +/* Privilege level is relative in $sps, so 1 indicates current PL + 1 */ +#define user_mode(regs) (pl((regs)->sps) == MODE_USER) +#define es_ec(regs) kvx_sfr_field_val(regs->es, ES, EC) +#define es_sysno(regs) kvx_sfr_field_val(regs->es, ES, SN) + +#define debug_dc(es) kvx_sfr_field_val((es), ES, DC) + +/* ptrace */ +#define PTRACE_GET_HW_PT_REGS 20 +#define PTRACE_SET_HW_PT_REGS 21 +#define arch_has_single_step() 1 + +#define DEBUG_CAUSE_BREAKPOINT 0 +#define DEBUG_CAUSE_WATCHPOINT 1 +#define DEBUG_CAUSE_STEPI 2 +#define DEBUG_CAUSE_DSU_BREAK 3 + +static inline void enable_single_step(struct pt_regs *regs) +{ + regs->sps |= KVX_SFR_PS_SME_MASK; +} + +static inline void disable_single_step(struct pt_regs *regs) +{ + regs->sps &= ~KVX_SFR_PS_SME_MASK; +} + +static inline bool in_syscall(struct pt_regs const *regs) +{ + return es_ec(regs) == ES_SYSCALL; +} + +int do_syscall_trace_enter(struct pt_regs *regs, unsigned long syscall); +void do_syscall_trace_exit(struct pt_regs *regs); + +static inline unsigned long get_current_sp(void) +{ + register const unsigned long current_sp __asm__ ("$r12"); + + return current_sp; +} + +extern char *user_scall_rt_sigreturn_end; +extern char *user_scall_rt_sigreturn; + +static inline unsigned long instruction_pointer(struct pt_regs *regs) +{ + return regs->spc; +} + +static inline long regs_return_value(struct pt_regs *regs) +{ + return regs->r0; +} + +static inline unsigned long user_stack_pointer(struct pt_regs *regs) +{ + return regs->sp; +} + +#endif /* _ASM_KVX_PTRACE_H */ diff --git a/arch/kvx/include/asm/switch_to.h b/arch/kvx/include/asm/switch_to.h new file mode 100644 index 000000000000..2b1fda06dea8 --- /dev/null +++ b/arch/kvx/include/asm/switch_to.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + */ + +#ifndef _ASM_KVX_SWITCH_TO_H +#define _ASM_KVX_SWITCH_TO_H + +struct task_struct; + +/* context switching is now performed out-of-line in switch_to.S */ +extern struct task_struct *__switch_to(struct task_struct *prev, + struct task_struct *next); + +#define switch_to(prev, next, last) \ + do { \ + ((last) = __switch_to((prev), (next))); \ + } while (0) + +#endif /* _ASM_KVX_SWITCH_TO_H */ diff --git a/arch/kvx/include/asm/thread_info.h b/arch/kvx/include/asm/thread_info.h new file mode 100644 index 000000000000..4ce0154813ef --- /dev/null +++ b/arch/kvx/include/asm/thread_info.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + * Guillaume Thouvenin + */ + +#ifndef _ASM_KVX_THREAD_INFO_H +#define _ASM_KVX_THREAD_INFO_H + +#include <asm/page.h> + +/* + * Size of the kernel stack for each process. + */ +#define THREAD_SIZE_ORDER 2 +#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) + +/* + * Thread information flags + * these are process state flags that various assembly files may need to + * access + * - pending work-to-be-done flags are in LSW + * - other flags in MSW + */ +#define TIF_SYSCALL_TRACE 0 /* syscall trace active */ +#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ +#define TIF_SIGPENDING 2 /* signal pending */ +#define TIF_NEED_RESCHED 3 /* rescheduling necessary */ +#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ +#define TIF_UPROBE 5 +#define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */ +#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ +#define TIF_RESTORE_SIGMASK 9 +#define TIF_NOTIFY_SIGNAL 10 /* signal notifications exist */ +#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ +#define TIF_MEMDIE 17 + +#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) +#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) +#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) +#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) +#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) +#define _TIF_SIGPENDING (1 << TIF_SIGPENDING) +#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) +#define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) + +#define _TIF_WORK_MASK \ + (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED) + +#define _TIF_SYSCALL_WORK \ + (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT) + +#ifndef __ASSEMBLY__ +/* + * We are using THREAD_INFO_IN_TASK so this struct is almost useless + * please prefer adding fields in thread_struct (processor.h) rather + * than here. + * This struct is merely a remnant of distant times where it was placed + * on the stack to avoid large task_struct. + * + * cf https://lwn.net/Articles/700615/ + */ +struct thread_info { + unsigned long flags; /* low level flags */ + int preempt_count; +#ifdef CONFIG_SMP + u32 cpu; /* current CPU */ +#endif +}; + +#define INIT_THREAD_INFO(tsk) \ +{ \ + .flags = 0, \ + .preempt_count = INIT_PREEMPT_COUNT, \ +} +#endif /* __ASSEMBLY__*/ +#endif /* _ASM_KVX_THREAD_INFO_H */ diff --git a/arch/kvx/include/uapi/asm/ptrace.h b/arch/kvx/include/uapi/asm/ptrace.h new file mode 100644 index 000000000000..f5febe830526 --- /dev/null +++ b/arch/kvx/include/uapi/asm/ptrace.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + * Yann Sionneau + */ + +#ifndef _UAPI_ASM_KVX_PTRACE_H +#define _UAPI_ASM_KVX_PTRACE_H + +#include <linux/types.h> +/* + * User-mode register state for core dumps, ptrace, sigcontext + * + * This decouples struct pt_regs from the userspace ABI. + * The struct pt_regs must start with the same layout as struct user_pt_regs. + */ +struct user_pt_regs { + /* GPR */ + unsigned long r0; + unsigned long r1; + unsigned long r2; + unsigned long r3; + unsigned long r4; + unsigned long r5; + unsigned long r6; + unsigned long r7; + unsigned long r8; + unsigned long r9; + unsigned long r10; + unsigned long r11; + union { + unsigned long r12; + unsigned long sp; + }; + union { + unsigned long r13; + unsigned long tp; + }; + union { + unsigned long r14; + unsigned long fp; + }; + unsigned long r15; + unsigned long r16; + unsigned long r17; + unsigned long r18; + unsigned long r19; + unsigned long r20; + unsigned long r21; + unsigned long r22; + unsigned long r23; + unsigned long r24; + unsigned long r25; + unsigned long r26; + unsigned long r27; + unsigned long r28; + unsigned long r29; + unsigned long r30; + unsigned long r31; + unsigned long r32; + unsigned long r33; + unsigned long r34; + unsigned long r35; + unsigned long r36; + unsigned long r37; + unsigned long r38; + unsigned long r39; + unsigned long r40; + unsigned long r41; + unsigned long r42; + unsigned long r43; + unsigned long r44; + unsigned long r45; + unsigned long r46; + unsigned long r47; + unsigned long r48; + unsigned long r49; + unsigned long r50; + unsigned long r51; + unsigned long r52; + unsigned long r53; + unsigned long r54; + unsigned long r55; + unsigned long r56; + unsigned long r57; + unsigned long r58; + unsigned long r59; + unsigned long r60; + unsigned long r61; + unsigned long r62; + unsigned long r63; + + /* SFR */ + unsigned long lc; + unsigned long le; + unsigned long ls; + unsigned long ra; + + unsigned long cs; + unsigned long spc; +}; + +/* TCA registers structure exposed to user */ +struct user_tca_regs { + struct { + __u64 x; + __u64 y; + __u64 z; + __u64 t; + } regs[48]; +}; + +#endif /* _UAPI_ASM_KVX_PTRACE_H */ diff --git a/arch/kvx/kernel/process.c b/arch/kvx/kernel/process.c new file mode 100644 index 000000000000..2a1cd0509604 --- /dev/null +++ b/arch/kvx/kernel/process.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + * Guillaume Thouvenin + * Marius Gligor + * Yann Sionneau + */ + +#include <linux/elf.h> +#include <linux/sched.h> +#include <linux/ptrace.h> +#include <linux/printk.h> +#include <linux/sched/debug.h> +#include <linux/sched/task_stack.h> + +#include <asm/ptrace.h> +#include <asm/processor.h> +#include <asm/ptrace.h> +#include <asm/uaccess.h> +#include <asm/stacktrace.h> + +#if defined(CONFIG_STACKPROTECTOR) +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + +#define SCALL_NUM_EXIT "0xfff" + +void arch_cpu_idle(void) +{ + wait_for_interrupt(); + local_irq_enable(); +} + +void show_regs(struct pt_regs *regs) +{ + + int in_kernel = 1; + unsigned short i, reg_offset; + void *ptr; + + show_regs_print_info(KERN_DEFAULT); + + if (user_mode(regs)) + in_kernel = 0; + + pr_info("\nmode: %s\n" + " PC: %016llx PS: %016llx\n" + " CS: %016llx RA: %016llx\n" + " LS: %016llx LE: %016llx\n" + " LC: %016llx\n\n", + in_kernel ? "kernel" : "user", + regs->spc, regs->sps, + regs->cs, regs->ra, regs->ls, regs->le, regs->lc); + + /* GPR */ + ptr = regs; + ptr += offsetof(struct pt_regs, r0); + reg_offset = offsetof(struct pt_regs, r1) - + offsetof(struct pt_regs, r0); + + /** + * Display all the 64 GPRs assuming they are ordered correctly + * in the pt_regs struct... + */ + for (i = 0; i < GPR_COUNT; i += 2) { + pr_info(" R%d: %016llx R%d: %016llx\n", + i, *(uint64_t *)ptr, + i + 1, *(uint64_t *)(ptr + reg_offset)); + ptr += reg_offset * 2; + } + + pr_info("\n\n"); +} + +/** + * Prepare a thread to return to userspace + */ +void start_thread(struct pt_regs *regs, + unsigned long pc, unsigned long sp) +{ + /* Remove MMUP bit (user is not privilege in current virtual space) */ + u64 clear_bit = KVX_SFR_PS_MMUP_MASK | KVX_SFR_PS_SME_MASK | + KVX_SFR_PS_SMR_MASK; + regs->spc = pc; + regs->sp = sp; + regs->sps = kvx_sfr_get(PS); + + regs->sps &= ~clear_bit; + + /* Set privilege level to +1 (relative) */ + regs->sps &= ~KVX_SFR_PS_PL_MASK; + regs->sps |= (1 << KVX_SFR_PS_PL_SHIFT); +} + +int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) +{ + struct pt_regs *regs, *childregs = task_pt_regs(p); + unsigned long clone_flags = args->flags; + unsigned long usp = args->stack; + unsigned long tls = args->tls; + + /* p->thread holds context to be restored by __switch_to() */ + if (unlikely(args->fn)) { + /* Kernel thread */ + memset(childregs, 0, sizeof(struct pt_regs)); + + p->thread.ctx_switch.r20 = (uint64_t)args->fn; /* fn */ + p->thread.ctx_switch.r21 = (uint64_t)args->fn_arg; + p->thread.ctx_switch.ra = + (unsigned long) ret_from_kernel_thread; + } else { + regs = current_pt_regs(); + + /* Copy current process registers */ + *childregs = *regs; + + /* Store tracing status in r20 to avoid computing it + * in assembly + */ + p->thread.ctx_switch.r20 = + task_thread_info(p)->flags & _TIF_SYSCALL_WORK; + p->thread.ctx_switch.ra = (unsigned long) ret_from_fork; + + childregs->r0 = 0; /* Return value of fork() */ + /* Set stack pointer if any */ + if (usp) + childregs->sp = usp; + + /* Set a new TLS ? */ + if (clone_flags & CLONE_SETTLS) + childregs->r13 = tls; + } + p->thread.kernel_sp = + (unsigned long) (task_stack_page(p) + THREAD_SIZE); + p->thread.ctx_switch.sp = (unsigned long) childregs; + + return 0; +} + +void release_thread(struct task_struct *dead_task) +{ +} + +void flush_thread(void) +{ +} + +/* Fill in the fpu structure for a core dump. */ +int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) +{ + /* + * On kvx, FPU uses standard registers + $cs which is a common register + * also needed for non-fpu execution, so there is no additional + * register to dump. + */ + return 0; +} + +static bool find_wchan(unsigned long pc, void *arg) +{ + unsigned long *p = arg; + + /* + * If the pc is in a scheduler function (waiting), then, this is the + * address where the process is currently stuck. Note that scheduler + * functions also include lock functions. This functions are + * materialized using annotation to put them is special text sections. + */ + if (!in_sched_functions(pc)) { + *p = pc; + return true; + } + + return false; +} + +/* + * __get_wchan is called to obtain "schedule()" caller function address. + */ +unsigned long __get_wchan(struct task_struct *p) +{ + unsigned long pc = 0; + struct stackframe frame; + + /* + * We need to obtain the task stack since we don't want the stack to + * move under our feet. + */ + if (!try_get_task_stack(p)) + return 0; + + start_stackframe(&frame, thread_saved_reg(p, fp), + thread_saved_reg(p, ra)); + walk_stackframe(p, &frame, find_wchan, &pc); + + put_task_stack(p); + + return pc; +} + diff --git a/arch/kvx/kernel/ptrace.c b/arch/kvx/kernel/ptrace.c new file mode 100644 index 000000000000..aacae5883cb5 --- /dev/null +++ b/arch/kvx/kernel/ptrace.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * derived from arch/riscv/kernel/ptrace.c + * + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Marius Gligor + * Clement Leger + */ + +#include <linux/sched.h> +#include <linux/sched.h> +#include <linux/audit.h> +#include <linux/irqflags.h> +#include <linux/thread_info.h> +#include <linux/context_tracking.h> +#include <linux/uaccess.h> +#include <linux/syscalls.h> +#include <linux/signal.h> +#include <linux/regset.h> +#include <linux/hw_breakpoint.h> + +#include <asm/dame.h> +#include <asm/ptrace.h> +#include <asm/syscall.h> +#include <asm/break_hook.h> +#include <asm/debug.h> +#include <asm/cacheflush.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/syscalls.h> + +#define HW_PT_CMD_GET_CAPS 0 +#define HW_PT_CMD_GET_PT 1 +#define HW_PT_CMD_SET_RESERVE 0 +#define HW_PT_CMD_SET_ENABLE 1 + +#define FROM_GDB_CMD_MASK 3 +#define FROM_GDB_HP_TYPE_SHIFT 2 +#define FROM_GDB_HP_TYPE_MASK 4 +#define FROM_GDB_WP_TYPE_SHIFT 3 +#define FROM_GDB_WP_TYPE_MASK 0x18 +#define FROM_GDB_HP_IDX_SHIFT 5 + +#define hw_pt_cmd(addr) ((addr) & FROM_GDB_CMD_MASK) +#define hw_pt_is_bkp(addr) ((((addr) & FROM_GDB_HP_TYPE_MASK) >> \ + FROM_GDB_HP_TYPE_SHIFT) == KVX_HW_BREAKPOINT_TYPE) +#define get_hw_pt_wp_type(addr) ((((addr) & FROM_GDB_WP_TYPE_MASK)) >> \ + FROM_GDB_WP_TYPE_SHIFT) +#define get_hw_pt_idx(addr) ((addr) >> FROM_GDB_HP_IDX_SHIFT) +#define get_hw_pt_addr(data) ((data)[0]) +#define get_hw_pt_len(data) ((data)[1] >> 1) +#define hw_pt_is_enabled(data) ((data)[1] & 1) + +enum kvx_regset { + REGSET_GPR, +#ifdef CONFIG_ENABLE_TCA + REGSET_TCA, +#endif +}; + +void ptrace_disable(struct task_struct *child) +{ + /* nothing to do */ +} + +static int kvx_gpr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct user_pt_regs *regs = &task_pt_regs(target)->user_regs; + + return membuf_write(&to, regs, sizeof(*regs)); +} + +static int kvx_gpr_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct user_pt_regs *regs = &task_pt_regs(target)->user_regs; + + return user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1); +} + +#ifdef CONFIG_ENABLE_TCA +static int kvx_tca_reg_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct ctx_switch_regs *ctx_regs = &target->thread.ctx_switch; + struct tca_reg *regs = ctx_regs->tca_regs; + int ret; + + if (!ctx_regs->tca_regs_saved) + ret = membuf_zero(&to, sizeof(*regs)); + else + ret = membuf_write(&to, regs, sizeof(*regs)); + + return ret; +} + +static int kvx_tca_reg_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct ctx_switch_regs *ctx_regs = &target->thread.ctx_switch; + struct tca_reg *regs = ctx_regs->tca_regs; + int ret; + + if (!ctx_regs->tca_regs_saved) + ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + 0, -1); + else + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, + 0, -1); + + return ret; +} +#endif + +static const struct user_regset kvx_user_regset[] = { + [REGSET_GPR] = { + .core_note_type = NT_PRSTATUS, + .n = ELF_NGREG, + .size = sizeof(elf_greg_t), + .align = sizeof(elf_greg_t), + .regset_get = &kvx_gpr_get, + .set = &kvx_gpr_set, + }, +#ifdef CONFIG_ENABLE_TCA + [REGSET_TCA] = { + .core_note_type = NT_KVX_TCA, + .n = TCA_REG_COUNT, + .size = sizeof(struct tca_reg), + .align = sizeof(struct tca_reg), + .regset_get = &kvx_tca_reg_get, + .set = &kvx_tca_reg_set, + }, +#endif +}; + +static const struct user_regset_view user_kvx_view = { + .name = "kvx", + .e_machine = EM_KVX, + .regsets = kvx_user_regset, + .n = ARRAY_SIZE(kvx_user_regset) +}; + +const struct user_regset_view *task_user_regset_view(struct task_struct *task) +{ + return &user_kvx_view; +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + return ptrace_request(child, request, addr, data); +} + +/* + * Allows PTRACE_SYSCALL to work. These are called from entry.S in + * {handle,ret_from}_syscall. + */ +int do_syscall_trace_enter(struct pt_regs *regs, unsigned long syscall) +{ + int ret = 0; + +#ifdef CONFIG_CONTEXT_TRACKING_USER + user_exit_callable(); +#endif + if (test_thread_flag(TIF_SYSCALL_TRACE)) + ret = ptrace_report_syscall_entry(regs); + +#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_enter(regs, syscall_get_nr(current, regs)); +#endif + + audit_syscall_entry(syscall, regs->r0, regs->r1, regs->r2, regs->r3); + + return ret; +} + +void do_syscall_trace_exit(struct pt_regs *regs) +{ + if (test_thread_flag(TIF_SYSCALL_TRACE)) + ptrace_report_syscall_exit(regs, 0); + + audit_syscall_exit(regs); + +#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_exit(regs, regs_return_value(regs)); +#endif + +#ifdef CONFIG_CONTEXT_TRACKING_USER + user_enter_callable(); +#endif +} + +static int kvx_bkpt_handler(struct break_hook *brk_hook, struct pt_regs *regs) +{ + /* Unexpected breakpoint */ + if (!(current->ptrace & PT_PTRACED)) + return BREAK_HOOK_ERROR; + + /* deliver the signal to userspace */ + force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->spc); + + return BREAK_HOOK_HANDLED; +} + +static void kvx_stepi(struct pt_regs *regs) +{ + /* deliver the signal to userspace */ + force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *) regs->spc); +} + +void user_enable_single_step(struct task_struct *child) +{ + struct pt_regs *regs = task_pt_regs(child); + + enable_single_step(regs); +} + +void user_disable_single_step(struct task_struct *child) +{ + struct pt_regs *regs = task_pt_regs(child); + + disable_single_step(regs); +} + +/** + * Main debug handler called by the _debug_handler routine in entry.S + * This handler will perform the required action + * @es: Exception Syndrome register value + * @ea: Exception Address register + * @regs: pointer to registers saved when enter debug + */ +int ptrace_debug_handler(u64 ea, struct pt_regs *regs) +{ + + int debug_cause = debug_dc(regs->es); + + switch (debug_cause) { + case DEBUG_CAUSE_STEPI: + kvx_stepi(regs); + break; + default: + break; + } + + return DEBUG_HOOK_HANDLED; +} + +static struct debug_hook ptrace_debug_hook = { + .handler = ptrace_debug_handler, + .mode = MODE_USER, +}; + +static struct break_hook bkpt_break_hook = { + .id = BREAK_CAUSE_BKPT, + .handler = kvx_bkpt_handler, + .mode = MODE_USER, +}; + +static int __init arch_init_breakpoint(void) +{ + break_hook_register(&bkpt_break_hook); + debug_hook_register(&ptrace_debug_hook); + + return 0; +} + +postcore_initcall(arch_init_breakpoint); diff --git a/arch/kvx/kernel/stacktrace.c b/arch/kvx/kernel/stacktrace.c new file mode 100644 index 000000000000..85d52ba2d082 --- /dev/null +++ b/arch/kvx/kernel/stacktrace.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + * Vincent Chardon + */ + +#include <linux/context_tracking.h> +#include <linux/kallsyms.h> +#include <linux/printk.h> +#include <linux/init.h> + +#include <asm/stacktrace.h> +#include <asm/ptrace.h> + +#define STACK_SLOT_PER_LINE 4 +#define STACK_MAX_SLOT_PRINT (STACK_SLOT_PER_LINE * 8) + +static int notrace unwind_frame(struct task_struct *task, + struct stackframe *frame) +{ + unsigned long fp = frame->fp; + + /* Frame pointer must be aligned on 8 bytes */ + if (fp & 0x7) + return -EINVAL; + + if (!task) + task = current; + + if (!on_task_stack(task, fp)) + return -EINVAL; + + frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); + frame->ra = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8)); + + /* + * When starting, we set the frame pointer to 0, hence end of + * frame linked list is signal by that + */ + if (!frame->fp) + return -EINVAL; + + return 0; +} + +void notrace walk_stackframe(struct task_struct *task, struct stackframe *frame, + bool (*fn)(unsigned long, void *), void *arg) +{ + unsigned long addr; + int ret; + + while (1) { + addr = frame->ra; + + if (fn(addr, arg)) + break; + + ret = unwind_frame(task, frame); + if (ret) + break; + } +} + +#ifdef CONFIG_STACKTRACE +bool append_stack_addr(unsigned long pc, void *arg) +{ + struct stack_trace *trace; + + trace = (struct stack_trace *)arg; + if (trace->skip == 0) { + trace->entries[trace->nr_entries++] = pc; + if (trace->nr_entries == trace->max_entries) + return true; + } else { + trace->skip--; + } + + return false; +} + +/* + * Save stack-backtrace addresses into a stack_trace buffer. + */ +void save_stack_trace(struct stack_trace *trace) +{ + struct stackframe frame; + + trace->nr_entries = 0; + /* We want to skip this function and the caller */ + trace->skip += 2; + + start_stackframe(&frame, (unsigned long) __builtin_frame_address(0), + (unsigned long) save_stack_trace); + walk_stackframe(current, &frame, append_stack_addr, trace); +} +EXPORT_SYMBOL(save_stack_trace); +#endif /* CONFIG_STACKTRACE */ + +static bool print_pc(unsigned long pc, void *arg) +{ + unsigned long *skip = arg; + + if (*skip == 0) + print_ip_sym(KERN_INFO, pc); + else + (*skip)--; + + return false; +} + +void show_stacktrace(struct task_struct *task, struct pt_regs *regs) +{ + struct stackframe frame; + unsigned long skip = 0; + + /* Obviously, we can't backtrace on usermode ! */ + if (regs && user_mode(regs)) + return; + + if (!task) + task = current; + + if (!try_get_task_stack(task)) + return; + + if (regs) { + start_stackframe(&frame, regs->fp, regs->spc); + } else if (task == current) { + /* Skip current function and caller */ + skip = 2; + start_stackframe(&frame, + (unsigned long) __builtin_frame_address(0), + (unsigned long) show_stacktrace); + } else { + /* task blocked in __switch_to */ + start_stackframe(&frame, + thread_saved_reg(task, fp), + thread_saved_reg(task, ra)); + } + + pr_info("Call Trace:\n"); + walk_stackframe(task, &frame, print_pc, &skip); + + put_task_stack(task); +} + +/* + * If show_stack is called with a non-null task, then the task will have been + * claimed with try_get_task_stack by the caller. If task is NULL or current + * then there is no need to get task stack since it's our current stack... + */ +void show_stack(struct task_struct *task, unsigned long *sp) +{ + int i = 0; + + if (!sp) + sp = (unsigned long *) get_current_sp(); + + pr_info("Stack dump (@%p):\n", sp); + for (i = 0; i < STACK_MAX_SLOT_PRINT; i++) { + if (kstack_end(sp)) + break; + + if (i && (i % STACK_SLOT_PER_LINE) == 0) + pr_cont("\n\t"); + + pr_cont("%016lx ", *sp++); + } + pr_cont("\n"); + + show_stacktrace(task, NULL); +} -- 2.37.2