From: Vincent Chen vincent.chen@sifive.com
[ Upstream commit 8b04825ed205da38754f86f4c07ea8600d8c2a65 ]
When the CONFIG_GENERIC_BUG is disabled by disabling CONFIG_BUG, if a kernel thread is trapped by BUG(), the whole system will be in the loop that infinitely handles the ebreak exception instead of entering the die function. To fix this problem, the do_trap_break() will always call the die() to deal with the break exception as the type of break is BUG_TRAP_TYPE_BUG.
Signed-off-by: Vincent Chen vincent.chen@sifive.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Paul Walmsley paul.walmsley@sifive.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kernel/traps.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 424eb72d56b10..055a937aca70a 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -124,23 +124,23 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
asmlinkage void do_trap_break(struct pt_regs *regs) { -#ifdef CONFIG_GENERIC_BUG if (!user_mode(regs)) { enum bug_trap_type type;
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); break; case BUG_TRAP_TYPE_BUG: +#endif /* CONFIG_GENERIC_BUG */ + default: die(regs, "Kernel BUG"); } } -#endif /* CONFIG_GENERIC_BUG */ - force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc)); }