android_kernel_motorola_sm6225/arch/um/os-Linux
Stanislaw Gruszka 4dbed85a35 uml: stop gdb from deleting breakpoints when running UML
Sometimes when UML is debugged gdb miss breakpoints.

When process traced by gdb do fork, debugger remove breakpoints from
child address space. There is possibility to trace more than one fork,
but this not work with UML, I guess (only guess) there is a deadlock -
gdb waits for UML and UML waits for gdb.

When clone() is called with SIGCHLD and CLONE_VM flags, gdb see this
as PTRACE_EVENT_FORK not as PTRACE_EVENT_CLONE and remove breakpoints
from child and at the same time from traced process, because either
have the same address space.

Maybe it is possible to do fix in gdb, but I'm not sure if there is
easy way to find out if traced and child processes share memory. So I
do fix for UML, it simply do not call clone() with both SIGCHLD and
CLONE_VM flags together.  Additionally __WALL flag is used for
waitpid() to assure not miss clone and normal process events.

[ jdike - checkpatch fixes ]

Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
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>
2007-12-17 19:28:15 -08:00
..
drivers uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00
include Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
skas uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -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: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -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: fix recvmsg return value checking 2007-11-14 18:45:37 -08:00
helper.c uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00
irq.c uml: eliminate SIGALRM 2007-10-16 09:43:08 -07:00
main.c uml: eliminate SIGALRM 2007-10-16 09:43:08 -07:00
Makefile uml: style fixes pass 1 2007-10-16 09:43:05 -07:00
mem.c uml: userspace files should call libc directly 2007-10-16 09:43:06 -07:00
process.c uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00
registers.c uml: floating point signal delivery fixes 2007-10-16 09:43:07 -07:00
sigio.c uml: Eliminate kernel allocator wrappers 2007-07-16 09:05:38 -07:00
signal.c uml: eliminate SIGALRM 2007-10-16 09:43:08 -07:00
start_up.c uml: userspace files should call libc directly 2007-10-16 09:43:06 -07:00
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
trap.c uml: eliminate SIGALRM 2007-10-16 09:43:08 -07:00
tty.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tty_log.c uml: convert libc layer to call read and write 2007-05-07 12:13:03 -07:00
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