tmp_suning_uos_patched/arch/um/os-Linux
Jeff Dike 3e6f2ac480 uml: kill processes instead of panicing kernel
UML was panicing in the case of failures of libc calls which shouldn't happen.
 This is an overreaction since a failure from libc doesn't normally mean that
kernel data structures are in an unknown state.  Instead, the current process
should just be killed if there is no way to recover.

The case that prompted this was a failure of PTRACE_SETREGS restoring the same
state that was read by PTRACE_GETREGS.  It appears that when a process tries
to load a bogus value into a segment register, it segfaults (as expected) and
the value is actually loaded and is seen by PTRACE_GETREGS (not expected).

This case is fixed by forcing a fatal SIGSEGV on the process so that it
immediately dies.  fatal_sigsegv was added for this purpose.  It was declared
as noreturn, so in order to pursuade gcc that it actually does not return, I
added a call to os_dump_core (and declared it noreturn) so that I get a core
file if somehow the process survives.

All other calls in arch/um/os-Linux/skas/process.c got the same treatment,
with failures causing the process to die instead of a kernel panic, with some
exceptions.

userspace_tramp exits with status 1 if anything goes wrong there.  That will
cause start_userspace to return an error.  copy_context_skas0 and
map_stub_pages also now return errors instead of panicing.  Callers of thes
functions were changed to check for errors and do something appropriate.
Usually that's to return an error to their callers.
check_skas3_ptrace_faultinfo just exits since that's too early to do anything
else.

save_registers, restore_registers, and init_registers now return status
instead of panicing on failure, with their callers doing something
appropriate.

There were also duplicate declarations of save_registers and restore_registers
in os.h - these are gone.

I noticed and fixed up some whitespace damage.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:28 -08:00
..
drivers uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
include Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
skas uml: kill processes instead of panicing kernel 2008-02-05 09:44:28 -08:00
sys-i386 uml: style fixes in FP code 2007-10-16 09:43:07 -07:00
sys-x86_64 uml: throw out CONFIG_MODE_TT 2007-10-16 09:43:05 -07:00
aio.c uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
elf_aux.c [PATCH] uml: host VDSO fix 2007-03-01 14:53:38 -08:00
execvp.c [PATCH] uml: make execvp safe for our usage 2006-11-25 13:28:34 -08:00
file.c uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
helper.c uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00
irq.c uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
main.c uml: code tidying under arch/um/os-Linux 2008-02-05 09:44:24 -08:00
Makefile uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
mem.c uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
process.c uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00
registers.c uml: kill processes instead of panicing kernel 2008-02-05 09:44:28 -08:00
sigio.c arch/um: remove duplicate includes 2008-02-05 09:44:26 -08:00
signal.c uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
start_up.c uml: kill processes instead of panicing kernel 2008-02-05 09:44:28 -08:00
time.c uml: after_sleep_interval should return something 2007-12-03 08:13:17 -08:00
tls.c uml: style fixes pass 1 2007-10-16 09:43:05 -07:00
tty_log.c uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
tty.c uml: tidy kern_util.h 2008-02-05 09:44:26 -08:00
uaccess.c uml: get rid of do_longjmp 2007-10-16 09:43:05 -07:00
umid.c uml: style fixes pass 3 2007-10-16 09:43:05 -07:00
user_syms.c uml: fix string exporting on UML/i386 2007-07-24 12:24:58 -07:00
util.c uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00