ebiederm@xxxxxxxxxxxx (Eric W. Biederman) writes: > 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> Any chance I can get an ack on this patch? Eric > --- > arch/m68k/fpsp040/skeleton.S | 3 ++- > arch/m68k/kernel/traps.c | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/m68k/fpsp040/skeleton.S b/arch/m68k/fpsp040/skeleton.S > index a8f41615d94a..439395aa6fb4 100644 > --- a/arch/m68k/fpsp040/skeleton.S > +++ b/arch/m68k/fpsp040/skeleton.S > @@ -502,7 +502,8 @@ in_ea: > .section .fixup,#alloc,#execinstr > .even > 1: > - jbra fpsp040_die > + jbsr fpsp040_die > + jbra .Lnotkern > > .section __ex_table,#alloc > .align 4 > 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
