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authorVincent Chen <vincent.chen@sifive.com>2019-09-23 03:45:16 +0300
committerPaul Walmsley <paul.walmsley@sifive.com>2019-10-07 22:59:41 +0300
commit8bb0daef64e5a92db63ad1d3bbf9e280a7b3612a (patch)
treeb56848d150a8be8b712e8ef975a5d9830238381a /arch
parente0c0fc18f10d5080cddde0e81505fd3e952c20c4 (diff)
downloadlinux-8bb0daef64e5a92db63ad1d3bbf9e280a7b3612a.tar.xz
riscv: Correct the handling of unexpected ebreak in do_trap_break()
For the kernel space, all ebreak instructions are determined at compile time because the kernel space debugging module is currently unsupported. Hence, it should be treated as a bug if an ebreak instruction which does not belong to BUG_TRAP_TYPE_WARN or BUG_TRAP_TYPE_BUG is executed in kernel space. For the userspace, debugging module or user problem may intentionally insert an ebreak instruction to trigger a SIGTRAP signal. To approach the above two situations, the do_trap_break() will direct the BUG_TRAP_TYPE_NONE ebreak exception issued in kernel space to die() and will send a SIGTRAP to the trapped process only when the ebreak is in userspace. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> [paul.walmsley@sifive.com: fixed checkpatch issue] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/riscv/kernel/traps.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 82f42a55451e..93742df9067f 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -130,8 +130,6 @@ asmlinkage void do_trap_break(struct pt_regs *regs)
type = report_bug(regs->sepc, regs);
switch (type) {
#ifdef CONFIG_GENERIC_BUG
- case BUG_TRAP_TYPE_NONE:
- break;
case BUG_TRAP_TYPE_WARN:
regs->sepc += get_break_insn_length(regs->sepc);
return;
@@ -140,8 +138,10 @@ asmlinkage void do_trap_break(struct pt_regs *regs)
default:
die(regs, "Kernel BUG");
}
+ } else {
+ force_sig_fault(SIGTRAP, TRAP_BRKPT,
+ (void __user *)(regs->sepc));
}
- force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc));
}
#ifdef CONFIG_GENERIC_BUG