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From: guoren@kernel.org
To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com,
	tglx@linutronix.de, peterz@infradead.org, luto@kernel.org,
	conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org,
	lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org,
	apatel@ventanamicro.com, atishp@atishpatra.org,
	mark.rutland@arm.com, ben@decadent.org.uk, bjorn@kernel.org
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org,
	"Guo Ren" <guoren@linux.alibaba.com>,
	"Björn Töpel" <bjorn@rivosinc.com>
Subject: [PATCH -next V13 3/7] riscv: entry: Add noinstr to prevent instrumentation inserted
Date: Sat,  7 Jan 2023 06:38:34 -0500	[thread overview]
Message-ID: <20230107113838.3969149-4-guoren@kernel.org> (raw)
In-Reply-To: <20230107113838.3969149-1-guoren@kernel.org>

From: Guo Ren <guoren@linux.alibaba.com>

Without noinstr the compiler is free to insert instrumentation (think
all the k*SAN, KCov, GCov, ftrace etc..) which can call code we're not
yet ready to run this early in the entry path, for instance it could
rely on RCU which isn't on yet, or expect lockdep state. (by peterz)

Link: https://lore.kernel.org/linux-riscv/YxcQ6NoPf3AH0EXe@hirez.programming.kicks-ass.net/
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 arch/riscv/kernel/traps.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 549bde5c970a..96ec76c54ff2 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -95,9 +95,9 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
 }
 
 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_RISCV_ALTERNATIVE)
-#define __trap_section		__section(".xip.traps")
+#define __trap_section __noinstr_section(".xip.traps")
 #else
-#define __trap_section
+#define __trap_section noinstr
 #endif
 #define DO_ERROR_INFO(name, signo, code, str)				\
 asmlinkage __visible __trap_section void name(struct pt_regs *regs)	\
-- 
2.36.1


WARNING: multiple messages have this Message-ID (diff)
From: guoren@kernel.org
To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com,
	tglx@linutronix.de, peterz@infradead.org, luto@kernel.org,
	conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org,
	lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org,
	apatel@ventanamicro.com, atishp@atishpatra.org,
	mark.rutland@arm.com, ben@decadent.org.uk, bjorn@kernel.org
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org,
	"Guo Ren" <guoren@linux.alibaba.com>,
	"Björn Töpel" <bjorn@rivosinc.com>
Subject: [PATCH -next V13 3/7] riscv: entry: Add noinstr to prevent instrumentation inserted
Date: Sat,  7 Jan 2023 06:38:34 -0500	[thread overview]
Message-ID: <20230107113838.3969149-4-guoren@kernel.org> (raw)
In-Reply-To: <20230107113838.3969149-1-guoren@kernel.org>

From: Guo Ren <guoren@linux.alibaba.com>

Without noinstr the compiler is free to insert instrumentation (think
all the k*SAN, KCov, GCov, ftrace etc..) which can call code we're not
yet ready to run this early in the entry path, for instance it could
rely on RCU which isn't on yet, or expect lockdep state. (by peterz)

Link: https://lore.kernel.org/linux-riscv/YxcQ6NoPf3AH0EXe@hirez.programming.kicks-ass.net/
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 arch/riscv/kernel/traps.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 549bde5c970a..96ec76c54ff2 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -95,9 +95,9 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
 }
 
 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_RISCV_ALTERNATIVE)
-#define __trap_section		__section(".xip.traps")
+#define __trap_section __noinstr_section(".xip.traps")
 #else
-#define __trap_section
+#define __trap_section noinstr
 #endif
 #define DO_ERROR_INFO(name, signo, code, str)				\
 asmlinkage __visible __trap_section void name(struct pt_regs *regs)	\
-- 
2.36.1


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linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  parent reply	other threads:[~2023-01-07 11:40 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-07 11:38 [PATCH -next V13 0/7] riscv: Add GENERIC_ENTRY support guoren
2023-01-07 11:38 ` guoren
2023-01-07 11:38 ` [PATCH -next V13 1/7] compiler_types.h: Add __noinstr_section() for noinstr guoren
2023-01-07 11:38   ` guoren
2023-01-07 11:38 ` [PATCH -next V13 2/7] riscv: ptrace: Remove duplicate operation guoren
2023-01-07 11:38   ` guoren
2023-01-07 11:38 ` guoren [this message]
2023-01-07 11:38   ` [PATCH -next V13 3/7] riscv: entry: Add noinstr to prevent instrumentation inserted guoren
2023-01-07 11:38 ` [PATCH -next V13 4/7] riscv: entry: Convert to generic entry guoren
2023-01-07 11:38   ` guoren
2023-01-07 12:57   ` kernel test robot
2023-01-07 12:57     ` kernel test robot
2023-01-07 14:07     ` Guo Ren
2023-01-07 14:07       ` Guo Ren
2023-01-07 13:57   ` kernel test robot
2023-01-07 13:57     ` kernel test robot
2023-01-07 14:07   ` kernel test robot
2023-01-07 14:07     ` kernel test robot
2023-01-07 14:18   ` kernel test robot
2023-01-07 14:18     ` kernel test robot
2023-01-07 11:38 ` [PATCH -next V13 5/7] riscv: entry: Remove extra level wrappers of trace_hardirqs_{on,off} guoren
2023-01-07 11:38   ` guoren
2023-01-07 11:38 ` [PATCH -next V13 6/7] riscv: entry: Consolidate ret_from_kernel_thread into ret_from_fork guoren
2023-01-07 11:38   ` guoren
2023-01-07 11:38 ` [PATCH -next V13 7/7] riscv: entry: Consolidate general regs saving/restoring guoren
2023-01-07 11:38   ` guoren

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