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From:   Vincent Chen <vincentc@andestech.com>
To:     <palmer@sifive.com>, <aou@eecs.berkeley.edu>,
        <ebiederm@xmission.com>, <jimw@sifive.com>, <arnd@arndb.de>,
        <linux-riscv@lists.infradead.org>, <linux-kernel@vger.kernel.org>
CC:     <deanbo422@gmail.com>, <vincentc@andestech.com>
Subject: [PATCH 2/3] riscv: Support BUG() in kernel module
Date:   Thu, 28 Feb 2019 18:31:30 +0800
Message-ID: <1551349891-22683-3-git-send-email-vincentc@andestech.com>
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The kernel module is loaded into vmalloc region which is located below
to the PAGE_OFFSET. Hence the condition, pc < PAGE_OFFSET, in the
is_valid_bugaddr() will filter out all trap exceptions triggered
by kernel module. To support BUG() in kernel module, the condition is
changed to pc < VMALLOC_START.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
---
 arch/riscv/kernel/traps.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index deae0e5..dee0e5e 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -144,7 +144,7 @@ int is_valid_bugaddr(unsigned long pc)
 {
 	bug_insn_t insn;
 
-	if (pc < PAGE_OFFSET)
+	if (pc < VMALLOC_START)
 		return 0;
 	if (probe_kernel_address((bug_insn_t *)pc, insn))
 		return 0;
-- 
1.7.1