5 files changed, 15 insertions, 43 deletions

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index ac202f44a670..d959d207a40d 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -19,7 +19,7 @@ unsigned long elf_hwcap __read_mostly;
 static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
 
 #ifdef CONFIG_FPU
-bool has_fpu __read_mostly;
+__ro_after_init DEFINE_STATIC_KEY_FALSE(cpu_hwcap_fpu);
 #endif
 
 /**
@@ -59,7 +59,7 @@ bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit)
 }
 EXPORT_SYMBOL_GPL(__riscv_isa_extension_available);
 
-void riscv_fill_hwcap(void)
+void __init riscv_fill_hwcap(void)
 {
 	struct device_node *node;
 	const char *isa;
@@ -146,6 +146,6 @@ void riscv_fill_hwcap(void)
 
 #ifdef CONFIG_FPU
 	if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D))
-		has_fpu = true;
+		static_branch_enable(&cpu_hwcap_fpu);
 #endif
 }
diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index 10b965c34536..fbd127d5dc04 100644
--- a/arch/riscv/kernel/probes/kprobes.c
+++ b/arch/riscv/kernel/probes/kprobes.c
@@ -17,7 +17,7 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
 DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 
 static void __kprobes
-post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *);
+post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);
 
 static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
 {
@@ -43,7 +43,7 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
 		p->ainsn.api.handler((u32)p->opcode,
 					(unsigned long)p->addr, regs);
 
-	post_kprobe_handler(kcb, regs);
+	post_kprobe_handler(p, kcb, regs);
 }
 
 int __kprobes arch_prepare_kprobe(struct kprobe *p)
@@ -149,21 +149,6 @@ static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb,
 	regs->status = kcb->saved_status;
 }
 
-static void __kprobes
-set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr, struct kprobe *p)
-{
-	unsigned long offset = GET_INSN_LENGTH(p->opcode);
-
-	kcb->ss_ctx.ss_pending = true;
-	kcb->ss_ctx.match_addr = addr + offset;
-}
-
-static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb)
-{
-	kcb->ss_ctx.ss_pending = false;
-	kcb->ss_ctx.match_addr = 0;
-}
-
 static void __kprobes setup_singlestep(struct kprobe *p,
 				       struct pt_regs *regs,
 				       struct kprobe_ctlblk *kcb, int reenter)
@@ -182,8 +167,6 @@ static void __kprobes setup_singlestep(struct kprobe *p,
 		/* prepare for single stepping */
 		slot = (unsigned long)p->ainsn.api.insn;
 
-		set_ss_context(kcb, slot, p);	/* mark pending ss */
-
 		/* IRQs and single stepping do not mix well. */
 		kprobes_save_local_irqflag(kcb, regs);
 
@@ -219,13 +202,8 @@ static int __kprobes reenter_kprobe(struct kprobe *p,
 }
 
 static void __kprobes
-post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
+post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs)
 {
-	struct kprobe *cur = kprobe_running();
-
-	if (!cur)
-		return;
-
 	/* return addr restore if non-branching insn */
 	if (cur->ainsn.api.restore != 0)
 		regs->epc = cur->ainsn.api.restore;
@@ -357,16 +335,16 @@ bool __kprobes
 kprobe_single_step_handler(struct pt_regs *regs)
 {
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	unsigned long addr = instruction_pointer(regs);
+	struct kprobe *cur = kprobe_running();
 
-	if ((kcb->ss_ctx.ss_pending)
-	    && (kcb->ss_ctx.match_addr == instruction_pointer(regs))) {
-		clear_ss_context(kcb);	/* clear pending ss */
-
+	if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) &&
+	    ((unsigned long)&cur->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) == addr)) {
 		kprobes_restore_local_irqflag(kcb, regs);
-
-		post_kprobe_handler(kcb, regs);
+		post_kprobe_handler(cur, kcb, regs);
 		return true;
 	}
+	/* not ours, kprobes should ignore it */
 	return false;
 }
 
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index f9cd57c9c67d..03ac3aa611f5 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -87,7 +87,7 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
 	unsigned long sp)
 {
 	regs->status = SR_PIE;
-	if (has_fpu) {
+	if (has_fpu()) {
 		regs->status |= SR_FS_INITIAL;
 		/*
 		 * Restore the initial value to the FP register
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 02d811127f48..b0c6f372a9ec 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -17,7 +17,6 @@
 #include <linux/of_fdt.h>
 #include <linux/of_platform.h>
 #include <linux/sched/task.h>
-#include <linux/swiotlb.h>
 #include <linux/smp.h>
 #include <linux/efi.h>
 #include <linux/crash_dump.h>
@@ -276,7 +275,6 @@ void __init setup_arch(char **cmdline_p)
 	parse_early_param();
 
 	efi_init();
-	setup_bootmem();
 	paging_init();
 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
 	unflatten_and_copy_device_tree();
@@ -291,10 +289,6 @@ void __init setup_arch(char **cmdline_p)
 	init_resources();
 	sbi_init();
 
-#ifdef CONFIG_SWIOTLB
-	swiotlb_init(1);
-#endif
-
 #ifdef CONFIG_KASAN
 	kasan_init();
 #endif
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 65942b3748b4..c2d5ecbe5526 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -90,7 +90,7 @@ static long restore_sigcontext(struct pt_regs *regs,
 	/* sc_regs is structured the same as the start of pt_regs */
 	err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs));
 	/* Restore the floating-point state. */
-	if (has_fpu)
+	if (has_fpu())
 		err |= restore_fp_state(regs, &sc->sc_fpregs);
 	return err;
 }
@@ -143,7 +143,7 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
 	/* sc_regs is structured the same as the start of pt_regs */
 	err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs));
 	/* Save the floating-point state. */
-	if (has_fpu)
+	if (has_fpu())
 		err |= save_fp_state(regs, &sc->sc_fpregs);
 	return err;
 }