| Message ID | 72a512bd5463ee04f4840f49cee2f3c3@linux-m68k.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [4.4.y-cip] signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die | expand |
Sorry, I saw these five minutes too late. Applied for the next release. CU Uli > On 02/13/2025 8:22 AM CET Finn Thain <fthain@linux-m68k.org> wrote: > > > From: "Eric W. Biederman" <ebiederm@xmission.com> > > [ Upstream commit a3616a3c02722d1edb95acc7fceade242f6553ba ] > > 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 <geert@linux-m68k.org> > Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> > [ Pass 'current' to force_sigsegv() as was done prior to v5.3 ] > Signed-off-by: Finn Thain <fthain@linux-m68k.org> > --- > 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 31a9c634c81e..081922c72daa 100644 > --- a/arch/m68k/fpsp040/skeleton.S > +++ b/arch/m68k/fpsp040/skeleton.S > @@ -502,7 +502,8 @@ in_ea: > .section .fixup,"ax" > .even > 1: > - jbra fpsp040_die > + jbsr fpsp040_die > + jbra .Lnotkern > > .section __ex_table,"a" > .align 4 > diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c > index 35f706d836c5..c6f18dc5884b 100644 > --- a/arch/m68k/kernel/traps.c > +++ b/arch/m68k/kernel/traps.c > @@ -1155,7 +1155,7 @@ asmlinkage void set_esp0(unsigned long ssp) > */ > asmlinkage void fpsp040_die(void) > { > - do_exit(SIGSEGV); > + force_sigsegv(SIGSEGV, current); > } > > #ifdef CONFIG_M68KFPU_EMU
diff --git a/arch/m68k/fpsp040/skeleton.S b/arch/m68k/fpsp040/skeleton.S index 31a9c634c81e..081922c72daa 100644 --- a/arch/m68k/fpsp040/skeleton.S +++ b/arch/m68k/fpsp040/skeleton.S @@ -502,7 +502,8 @@ in_ea: .section .fixup,"ax" .even 1: - jbra fpsp040_die + jbsr fpsp040_die + jbra .Lnotkern .section __ex_table,"a" .align 4 diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c index 35f706d836c5..c6f18dc5884b 100644 --- a/arch/m68k/kernel/traps.c +++ b/arch/m68k/kernel/traps.c @@ -1155,7 +1155,7 @@ asmlinkage void set_esp0(unsigned long ssp) */ asmlinkage void fpsp040_die(void) { - do_exit(SIGSEGV); + force_sigsegv(SIGSEGV, current); } #ifdef CONFIG_M68KFPU_EMU