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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-07-26 21:23:11 +0200 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-08-26 16:59:15 +0200 |
| commit | a3616a3c02722d1edb95acc7fceade242f6553ba (patch) | |
| tree | 50f31503491dafdc92a75b6946970ebfdb4ea93e /arch/m68k | |
| parent | exit/bdflush: Remove the deprecated bdflush system call (diff) | |
| download | linux-a3616a3c02722d1edb95acc7fceade242f6553ba.tar.xz linux-a3616a3c02722d1edb95acc7fceade242f6553ba.zip | |
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 <geert@linux-m68k.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'arch/m68k')
| -rw-r--r-- | arch/m68k/fpsp040/skeleton.S | 3 | ||||
| -rw-r--r-- | 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 |