[PATCH] riscv: vector: Mark riscv_v_context_nesting_start/end as noinstr

[hu.shengming]

From: Luo Haiyang <luo.haiyang@xxxxxxxxxx>

The functions riscv_v_context_nesting_start() and

riscv_v_context_nesting_end() are invoked in exception handling paths.

Allowing kprobes, function tracing on these functions could lead to

recursive exceptions or crashes.

Signed-off-by: Luo Haiyang <luo.haiyang@xxxxxxxxxx>

Signed-off-by: Shengming Hu <hu.shengming@xxxxxxxxxx>

---

 arch/riscv/kernel/kernel_mode_vector.c | 4 ++--

 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/kernel_mode_vector.c b/arch/riscv/kernel/kernel_mode_vector.c

index 99972a48e86b..1b2b9e4574b8 100644

--- a/arch/riscv/kernel/kernel_mode_vector.c

+++ b/arch/riscv/kernel/kernel_mode_vector.c

@@ -152,7 +152,7 @@ static int riscv_v_start_kernel_context(bool *is_nested)

 }

 

 /* low-level V context handling code, called with irq disabled */

-asmlinkage void riscv_v_context_nesting_start(struct pt_regs *regs)

+asmlinkage void noinstr riscv_v_context_nesting_start(struct pt_regs *regs)

 {

  int depth;

 

@@ -166,7 +166,7 @@ asmlinkage void riscv_v_context_nesting_start(struct pt_regs *regs)

  riscv_v_ctx_depth_inc();

 }

 

-asmlinkage void riscv_v_context_nesting_end(struct pt_regs *regs)

+asmlinkage void noinstr riscv_v_context_nesting_end(struct pt_regs *regs)

 {

  struct __riscv_v_ext_state *vstate = &current->thread.kernel_vstate;

  u32 depth;

-- 

2.25.1