On Mon, Jul 26, 2021 at 11:08 PM Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > 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: Link: https://lkml.kernel.org/r/87a6m8kgtx.fsf_-_@disp2133 > Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
