Merge tag 'arc-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC updates from Vineet Gupta:

 - Basic eBPF support (Sergey)

* tag 'arc-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: bpf: define uapi for BPF_PROG_TYPE_PERF_EVENT program type
  ARC: disasm: handle ARCv2 case in kprobe get/set functions
  ARC: implement syscall tracepoints
  ARC: enable HAVE_REGS_AND_STACK_ACCESS_API feature

arch/arc/Kconfig

@@ -36,8 +36,10 @@ config ARC
 	select HAVE_KERNEL_LZMA
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
+	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_PERF_EVENTS
+	select HAVE_SYSCALL_TRACEPOINTS
 	select IRQ_DOMAIN
 	select MODULES_USE_ELF_RELA
 	select OF

arch/arc/include/asm/perf_event.h

@@ -63,4 +63,8 @@ struct arc_reg_cc_build {
 
 #define PERF_COUNT_ARC_HW_MAX	(PERF_COUNT_HW_MAX + 8)
 
+#ifdef CONFIG_PERF_EVENTS
+#define perf_arch_bpf_user_pt_regs(regs) (struct user_regs_struct *)regs
+#endif
+
 #endif /* __ASM_PERF_EVENT_H */

arch/arc/include/asm/ptrace.h

@@ -8,6 +8,7 @@
 #define __ASM_ARC_PTRACE_H
 
 #include <uapi/asm/ptrace.h>
+#include <linux/compiler.h>
 
 #ifndef __ASSEMBLY__
 
@@ -54,6 +55,9 @@ struct pt_regs {
 
 	unsigned long user_r25;
 };
+
+#define MAX_REG_OFFSET offsetof(struct pt_regs, user_r25)
+
 #else
 
 struct pt_regs {
@@ -102,6 +106,8 @@ struct pt_regs {
 	unsigned long status32;
 };
 
+#define MAX_REG_OFFSET offsetof(struct pt_regs, status32)
+
 #endif
 
 /* Callee saved registers - need to be saved only when you are scheduled out */
@@ -154,6 +160,27 @@ static inline void instruction_pointer_set(struct pt_regs *regs,
 {
 	instruction_pointer(regs) = val;
 }
+
+static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
+{
+	return regs->sp;
+}
+
+extern int regs_query_register_offset(const char *name);
+extern const char *regs_query_register_name(unsigned int offset);
+extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
+extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
+					       unsigned int n);
+
+static inline unsigned long regs_get_register(struct pt_regs *regs,
+					      unsigned int offset)
+{
+	if (unlikely(offset > MAX_REG_OFFSET))
+		return 0;
+
+	return *(unsigned long *)((unsigned long)regs + offset);
+}
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ASM_PTRACE_H */

arch/arc/include/asm/syscall.h

@@ -12,6 +12,8 @@
 #include <asm/unistd.h>
 #include <asm/ptrace.h>		/* in_syscall() */
 
+extern void *sys_call_table[];
+
 static inline long
 syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
 {

arch/arc/include/asm/thread_info.h

@@ -78,9 +78,9 @@ static inline __attribute_const__ struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_AUDIT	4	/* syscall auditing active */
 #define TIF_NOTIFY_SIGNAL	5	/* signal notifications exist */
 #define TIF_SYSCALL_TRACE	15	/* syscall trace active */
-
 /* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		16
+#define TIF_SYSCALL_TRACEPOINT	17	/* syscall tracepoint instrumentation */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
@@ -89,11 +89,14 @@ static inline __attribute_const__ struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
 #define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
 #define _TIF_MEMDIE		(1<<TIF_MEMDIE)
+#define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
 				 _TIF_NOTIFY_RESUME | _TIF_NOTIFY_SIGNAL)
 
+#define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
+
 /*
  * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
  * SYSCALL_TRACE is anyway separately/unconditionally tested right after a

arch/arc/include/uapi/asm/bpf_perf_event.h

+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
+#define _UAPI__ASM_BPF_PERF_EVENT_H__
+
+#include <asm/ptrace.h>
+
+typedef struct user_regs_struct bpf_user_pt_regs_t;
+
+#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */

arch/arc/kernel/disasm.c

@@ -434,14 +434,31 @@ long __kprobes get_reg(int reg, struct pt_regs *regs,
 {
 	long *p;
 
+#if defined(CONFIG_ISA_ARCOMPACT)
 	if (reg <= 12) {
 		p = &regs->r0;
 		return p[-reg];
 	}
+#else /* CONFIG_ISA_ARCV2 */
+	if (reg <= 11) {
+		p = &regs->r0;
+		return p[reg];
+	}
 
+	if (reg == 12)
+		return regs->r12;
+	if (reg == 30)
+		return regs->r30;
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+	if (reg == 58)
+		return regs->r58;
+	if (reg == 59)
+		return regs->r59;
+#endif
+#endif
 	if (cregs && (reg <= 25)) {
 		p = &cregs->r13;
-		return p[13-reg];
+		return p[13 - reg];
 	}
 
 	if (reg == 26)
@@ -461,6 +478,7 @@ void __kprobes set_reg(int reg, long val, struct pt_regs *regs,
 {
 	long *p;
 
+#if defined(CONFIG_ISA_ARCOMPACT)
 	switch (reg) {
 	case 0 ... 12:
 		p = &regs->r0;
@@ -469,7 +487,7 @@ void __kprobes set_reg(int reg, long val, struct pt_regs *regs,
 	case 13 ... 25:
 		if (cregs) {
 			p = &cregs->r13;
-			p[13-reg] = val;
+			p[13 - reg] = val;
 		}
 		break;
 	case 26:
@@ -487,6 +505,48 @@ void __kprobes set_reg(int reg, long val, struct pt_regs *regs,
 	default:
 		break;
 	}
+#else /* CONFIG_ISA_ARCV2 */
+	switch (reg) {
+	case 0 ... 11:
+		p = &regs->r0;
+		p[reg] = val;
+		break;
+	case 12:
+		regs->r12 = val;
+		break;
+	case 13 ... 25:
+		if (cregs) {
+			p = &cregs->r13;
+			p[13 - reg] = val;
+		}
+		break;
+	case 26:
+		regs->r26 = val;
+		break;
+	case 27:
+		regs->fp = val;
+		break;
+	case 28:
+		regs->sp = val;
+		break;
+	case 30:
+		regs->r30 = val;
+		break;
+	case 31:
+		regs->blink = val;
+		break;
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+	case 58:
+		regs->r58 = val;
+		break;
+	case 59:
+		regs->r59 = val;
+		break;
+#endif
+	default:
+		break;
+	}
+#endif
 }
 
 /*

arch/arc/kernel/entry.S

@@ -29,8 +29,8 @@ ENTRY(sys_clone_wrapper)
 	DISCARD_CALLEE_SAVED_USER
 
 	GET_CURR_THR_INFO_FLAGS   r10
-	btst r10, TIF_SYSCALL_TRACE
-	bnz  tracesys_exit
+	and.f 0, r10, _TIF_SYSCALL_WORK
+	bnz   tracesys_exit
 
 	b .Lret_from_system_call
 END(sys_clone_wrapper)
@@ -41,8 +41,8 @@ ENTRY(sys_clone3_wrapper)
 	DISCARD_CALLEE_SAVED_USER
 
 	GET_CURR_THR_INFO_FLAGS   r10
-	btst r10, TIF_SYSCALL_TRACE
-	bnz  tracesys_exit
+	and.f 0, r10, _TIF_SYSCALL_WORK
+	bnz   tracesys_exit
 
 	b .Lret_from_system_call
 END(sys_clone3_wrapper)
@@ -247,8 +247,8 @@ ENTRY(EV_Trap)
 
 	; If syscall tracing ongoing, invoke pre-post-hooks
 	GET_CURR_THR_INFO_FLAGS   r10
-	btst r10, TIF_SYSCALL_TRACE
-	bnz tracesys  ; this never comes back
+	and.f 0, r10, _TIF_SYSCALL_WORK
+	bnz   tracesys  ; this never comes back
 
 	;============ Normal syscall case
 

arch/arc/kernel/ptrace.c

@@ -9,6 +9,92 @@
 #include <linux/unistd.h>
 #include <linux/elf.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+struct pt_regs_offset {
+	const char *name;
+	int offset;
+};
+
+#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+#ifdef CONFIG_ISA_ARCOMPACT
+static const struct pt_regs_offset regoffset_table[] = {
+	REG_OFFSET_NAME(bta),
+	REG_OFFSET_NAME(lp_start),
+	REG_OFFSET_NAME(lp_end),
+	REG_OFFSET_NAME(lp_count),
+	REG_OFFSET_NAME(status32),
+	REG_OFFSET_NAME(ret),
+	REG_OFFSET_NAME(blink),
+	REG_OFFSET_NAME(fp),
+	REG_OFFSET_NAME(r26),
+	REG_OFFSET_NAME(r12),
+	REG_OFFSET_NAME(r11),
+	REG_OFFSET_NAME(r10),
+	REG_OFFSET_NAME(r9),
+	REG_OFFSET_NAME(r8),
+	REG_OFFSET_NAME(r7),
+	REG_OFFSET_NAME(r6),
+	REG_OFFSET_NAME(r5),
+	REG_OFFSET_NAME(r4),
+	REG_OFFSET_NAME(r3),
+	REG_OFFSET_NAME(r2),
+	REG_OFFSET_NAME(r1),
+	REG_OFFSET_NAME(r0),
+	REG_OFFSET_NAME(sp),
+	REG_OFFSET_NAME(orig_r0),
+	REG_OFFSET_NAME(event),
+	REG_OFFSET_NAME(user_r25),
+	REG_OFFSET_END,
+};
+
+#else
+
+static const struct pt_regs_offset regoffset_table[] = {
+	REG_OFFSET_NAME(orig_r0),
+	REG_OFFSET_NAME(event),
+	REG_OFFSET_NAME(bta),
+	REG_OFFSET_NAME(user_r25),
+	REG_OFFSET_NAME(r26),
+	REG_OFFSET_NAME(fp),
+	REG_OFFSET_NAME(sp),
+	REG_OFFSET_NAME(r12),
+	REG_OFFSET_NAME(r30),
+#ifdef CONFIG_ARC_HAS_ACCL_REGS
+	REG_OFFSET_NAME(r58),
+	REG_OFFSET_NAME(r59),
+#endif
+#ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
+	REG_OFFSET_NAME(DSP_CTRL),
+#endif
+	REG_OFFSET_NAME(r0),
+	REG_OFFSET_NAME(r1),
+	REG_OFFSET_NAME(r2),
+	REG_OFFSET_NAME(r3),
+	REG_OFFSET_NAME(r4),
+	REG_OFFSET_NAME(r5),
+	REG_OFFSET_NAME(r6),
+	REG_OFFSET_NAME(r7),
+	REG_OFFSET_NAME(r8),
+	REG_OFFSET_NAME(r9),
+	REG_OFFSET_NAME(r10),
+	REG_OFFSET_NAME(r11),
+	REG_OFFSET_NAME(blink),
+	REG_OFFSET_NAME(lp_end),
+	REG_OFFSET_NAME(lp_start),
+	REG_OFFSET_NAME(lp_count),
+	REG_OFFSET_NAME(ei),
+	REG_OFFSET_NAME(ldi),
+	REG_OFFSET_NAME(jli),
+	REG_OFFSET_NAME(ret),
+	REG_OFFSET_NAME(status32),
+	REG_OFFSET_END,
+};
+#endif
+
 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
 {
 	struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
@@ -257,13 +343,61 @@ long arch_ptrace(struct task_struct *child, long request,
 
 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
 {
-	if (ptrace_report_syscall_entry(regs))
-		return ULONG_MAX;
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		if (ptrace_report_syscall_entry(regs))
+			return ULONG_MAX;
+
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_enter(regs, syscall_get_nr(current, regs));
+#endif
 
 	return regs->r8;
 }
 
 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
-	ptrace_report_syscall_exit(regs, 0);
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		ptrace_report_syscall_exit(regs, 0);
+
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_exit(regs, regs_return_value(regs));
+#endif
+}
+
+int regs_query_register_offset(const char *name)
+{
+	const struct pt_regs_offset *roff;
+
+	for (roff = regoffset_table; roff->name != NULL; roff++)
+		if (!strcmp(roff->name, name))
+			return roff->offset;
+	return -EINVAL;
+}
+
+const char *regs_query_register_name(unsigned int offset)
+{
+	const struct pt_regs_offset *roff;
+	for (roff = regoffset_table; roff->name != NULL; roff++)
+		if (roff->offset == offset)
+			return roff->name;
+	return NULL;
+}
+
+bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+	return (addr & ~(THREAD_SIZE - 1))  ==
+		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
+}
+
+unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+
+	addr += n;
+	if (regs_within_kernel_stack(regs, (unsigned long)addr))
+		return *addr;
+	else
+		return 0;
 }