From c88cfb5cea5f8f9868ef02cc9ce9183a26dcf20f Mon Sep 17 00:00:00 2001 From: Stafford Horne Date: Sat, 30 Mar 2024 14:42:49 +0000 Subject: openrisc: traps: Don't send signals to kernel mode threads OpenRISC exception handling sends signals to user processes on floating point exceptions and trap instructions (for debugging) among others. There is a bug where the trap handling logic may send signals to kernel threads, we should not send these signals to kernel threads, if that happens we treat it as an error. This patch adds conditions to die if the kernel receives these exceptions in kernel mode code. Fixes: 27267655c531 ("openrisc: Support floating point user api") Signed-off-by: Stafford Horne --- arch/openrisc/kernel/traps.c | 48 ++++++++++++++++++++++++++------------------ 1 file changed, 29 insertions(+), 19 deletions(-) (limited to 'arch/openrisc') diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c index 88fe27e4c10c..211ddaa0c5fa 100644 --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -180,29 +180,39 @@ asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector) asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address) { - int code = FPE_FLTUNK; - unsigned long fpcsr = regs->fpcsr; - - if (fpcsr & SPR_FPCSR_IVF) - code = FPE_FLTINV; - else if (fpcsr & SPR_FPCSR_OVF) - code = FPE_FLTOVF; - else if (fpcsr & SPR_FPCSR_UNF) - code = FPE_FLTUND; - else if (fpcsr & SPR_FPCSR_DZF) - code = FPE_FLTDIV; - else if (fpcsr & SPR_FPCSR_IXF) - code = FPE_FLTRES; - - /* Clear all flags */ - regs->fpcsr &= ~SPR_FPCSR_ALLF; - - force_sig_fault(SIGFPE, code, (void __user *)regs->pc); + if (user_mode(regs)) { + int code = FPE_FLTUNK; + unsigned long fpcsr = regs->fpcsr; + + if (fpcsr & SPR_FPCSR_IVF) + code = FPE_FLTINV; + else if (fpcsr & SPR_FPCSR_OVF) + code = FPE_FLTOVF; + else if (fpcsr & SPR_FPCSR_UNF) + code = FPE_FLTUND; + else if (fpcsr & SPR_FPCSR_DZF) + code = FPE_FLTDIV; + else if (fpcsr & SPR_FPCSR_IXF) + code = FPE_FLTRES; + + /* Clear all flags */ + regs->fpcsr &= ~SPR_FPCSR_ALLF; + + force_sig_fault(SIGFPE, code, (void __user *)regs->pc); + } else { + pr_emerg("KERNEL: Illegal fpe exception 0x%.8lx\n", regs->pc); + die("Die:", regs, SIGFPE); + } } asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) { - force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc); + if (user_mode(regs)) { + force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc); + } else { + pr_emerg("KERNEL: Illegal trap exception 0x%.8lx\n", regs->pc); + die("Die:", regs, SIGILL); + } } asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) -- cgit v1.2.3