Merge tag 'riscv-for-linus-5.14-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "We have a handful of new features for 5.14:

   - Support for transparent huge pages.

   - Support for generic PCI resources mapping.

   - Support for the mem= kernel parameter.

   - Support for KFENCE.

   - A handful of fixes to avoid W+X mappings in the kernel.

   - Support for VMAP_STACK based overflow detection.

   - An optimized copy_{to,from}_user"

* tag 'riscv-for-linus-5.14-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (37 commits)
  riscv: xip: Fix duplicate included asm/pgtable.h
  riscv: Fix PTDUMP output now BPF region moved back to module region
  riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall
  riscv: add VMAP_STACK overflow detection
  riscv: ptrace: add argn syntax
  riscv: mm: fix build errors caused by mk_pmd()
  riscv: Introduce structure that group all variables regarding kernel mapping
  riscv: Map the kernel with correct permissions the first time
  riscv: Introduce set_kernel_memory helper
  riscv: Enable KFENCE for riscv64
  RISC-V: Use asm-generic for {in,out}{bwlq}
  riscv: add ASID-based tlbflushing methods
  riscv: pass the mm_struct to __sbi_tlb_flush_range
  riscv: Add mem kernel parameter support
  riscv: Simplify xip and !xip kernel address conversion macros
  riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED
  riscv: Only initialize swiotlb when necessary
  riscv: fix typo in init.c
  riscv: Cleanup unused functions
  riscv: mm: Use better bitmap_zalloc()
  ...

1 files changed, 9 insertions, 31 deletions

diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index 247e33fa5bc7..00088dc6da4b 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)
@@ -151,21 +151,6 @@ 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)
@@ -184,8 +169,6 @@ 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);
 
@@ -221,13 +204,8 @@ 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;
@@ -342,16 +320,16 @@ 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;
 }