From a3616a3c02722d1edb95acc7fceade242f6553ba Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 26 Jul 2021 14:23:11 -0500 Subject: signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die In the fpsp040 code when copyin or copyout fails call force_sigsegv(SIGSEGV) instead of do_exit(SIGSEGV). This solves a couple of problems. Because do_exit embeds the ptrace stop PTRACE_EVENT_EXIT a complete stack frame needs to be present for that to work correctly. There is always the information needed for a ptrace stop where get_signal is called. So exiting with a signal solves the ptrace issue. Further exiting with a signal ensures that all of the threads in a process are killed not just the thread that malfunctioned. Which avoids confusing userspace. To make force_sigsegv(SIGSEGV) work in fpsp040_die modify the code to save all of the registers and jump to ret_from_exception (which ultimately calls get_signal) after fpsp040_die returns. v2: Updated the branches to use gas's pseudo ops that automatically calculate the best branch instruction to use for the purpose. v1: https://lkml.kernel.org/r/87a6m8kgtx.fsf_-_@disp2133 Link: https://lkml.kernel.org/r/87tukghjfs.fsf_-_@disp2133 Acked-by: Geert Uytterhoeven Signed-off-by: "Eric W. Biederman" --- arch/m68k/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/m68k/kernel') diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c index 9e1261462bcc..5b19fcdcd69e 100644 --- a/arch/m68k/kernel/traps.c +++ b/arch/m68k/kernel/traps.c @@ -1150,7 +1150,7 @@ asmlinkage void set_esp0(unsigned long ssp) */ asmlinkage void fpsp040_die(void) { - do_exit(SIGSEGV); + force_sigsegv(SIGSEGV); } #ifdef CONFIG_M68KFPU_EMU -- cgit