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From: Ben Dooks <ben.dooks@codethink.co.uk>
To: linux-riscv@lists.infradead.org
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Subject: [PATCH 2/3] riscv: traps: make insn fetch common in unknown instruction
Date: Tue, 17 Sep 2024 14:08:52 +0100	[thread overview]
Message-ID: <20240917130853.18657-3-ben.dooks@codethink.co.uk> (raw)
In-Reply-To: <20240917130853.18657-1-ben.dooks@codethink.co.uk>

Add the insn as the second argument to riscv_v_first_use_handler() form
the trap handler so when we add more handlers we can do the fetch of the
instruction just once.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
 arch/riscv/include/asm/vector.h |  4 ++--
 arch/riscv/kernel/traps.c       | 11 ++++++++++-
 arch/riscv/kernel/vector.c      | 11 +----------
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
index be7d309cca8a..c9f0b02cd975 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/arch/riscv/include/asm/vector.h
@@ -21,7 +21,7 @@
 
 extern unsigned long riscv_v_vsize;
 int riscv_v_setup_vsize(void);
-bool riscv_v_first_use_handler(struct pt_regs *regs);
+bool riscv_v_first_use_handler(struct pt_regs *regs, u32 insn);
 void kernel_vector_begin(void);
 void kernel_vector_end(void);
 void get_cpu_vector_context(void);
@@ -268,7 +268,7 @@ struct pt_regs;
 
 static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; }
 static __always_inline bool has_vector(void) { return false; }
-static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; }
+static inline bool riscv_v_first_use_handler(struct pt_regs *regs, u32 insn) { return false; }
 static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
 static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; }
 #define riscv_v_vsize (0)
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 51ebfd23e007..1c3fab272fd1 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -172,11 +172,20 @@ asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *re
 	bool handled;
 
 	if (user_mode(regs)) {
+		u32 __user *epc = (u32 __user *)regs->epc;
+		u32 insn = (u32)regs->badaddr;
+
 		irqentry_enter_from_user_mode(regs);
 
 		local_irq_enable();
 
-		handled = riscv_v_first_use_handler(regs);
+		if (!insn) {
+			if (__get_user(insn, epc)) {
+				/* todo */
+			}
+		}
+
+		handled = riscv_v_first_use_handler(regs, insn);
 
 		local_irq_disable();
 
diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
index 682b3feee451..b852648cb8d5 100644
--- a/arch/riscv/kernel/vector.c
+++ b/arch/riscv/kernel/vector.c
@@ -168,11 +168,8 @@ bool riscv_v_vstate_ctrl_user_allowed(void)
 }
 EXPORT_SYMBOL_GPL(riscv_v_vstate_ctrl_user_allowed);
 
-bool riscv_v_first_use_handler(struct pt_regs *regs)
+bool riscv_v_first_use_handler(struct pt_regs *regs, u32 insn)
 {
-	u32 __user *epc = (u32 __user *)regs->epc;
-	u32 insn = (u32)regs->badaddr;
-
 	if (!has_vector())
 		return false;
 
@@ -184,12 +181,6 @@ bool riscv_v_first_use_handler(struct pt_regs *regs)
 	if (riscv_v_vstate_query(regs))
 		return false;
 
-	/* Get the instruction */
-	if (!insn) {
-		if (__get_user(insn, epc))
-			return false;
-	}
-
 	/* Filter out non-V instructions */
 	if (!insn_is_vector(insn))
 		return false;
-- 
2.37.2.352.g3c44437643


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  parent reply	other threads:[~2024-09-17 14:13 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-17 13:08 RFC: extern illegal instruction trap and trap RDCYCLE Ben Dooks
2024-09-17 13:08 ` [PATCH 1/3] riscv: ptrace: add regs_set_register() Ben Dooks
2024-09-17 13:08 ` Ben Dooks [this message]
2024-09-17 13:08 ` [PATCH 3/3] riscv: add trap and emulation for RDCYCLE Ben Dooks
2024-09-17 14:08   ` Ben Dooks
2024-09-18  6:45   ` Andrew Jones
2024-09-18  9:07     ` Ben Dooks
2024-09-18  9:15     ` Ben Dooks
2024-09-17 13:46 ` RFC: extern illegal instruction trap and trap RDCYCLE Palmer Dabbelt
2024-09-17 14:01   ` Ben Dooks
2024-09-18  9:55     ` Atish Patra
2024-09-18  9:57       ` Ben Dooks
2024-09-18 23:23         ` Atish Kumar Patra
2024-10-01  9:41           ` Alexandre Ghiti
2024-10-01 21:00             ` Ben Dooks
2024-10-01 21:07               ` Ben Dooks
  -- strict thread matches above, loose matches on Subject: below --
2024-11-13  9:17 updates for instruction trapping and ptrace Ben Dooks
2024-11-13  9:17 ` [PATCH 2/3] riscv: traps: make insn fetch common in unknown instruction Ben Dooks
2024-11-13  9:21   ` Ben Dooks
2024-11-13  9:31     ` Ben Dooks

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