linux/arch/um
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 uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00
kernel uml: remove last include of libc asm/page.h 2007-11-14 18:45:43 -08:00
os-Linux uml: stop gdb from deleting breakpoints when running UML 2007-12-17 19:28:15 -08:00
scripts
sys-i386 misc uml annotation and section fixes 2007-10-29 07:41:32 -07:00
sys-ia64
sys-ppc
sys-x86_64 misc uml annotation and section fixes 2007-10-29 07:41:32 -07:00
defconfig
Kconfig
Kconfig.char
Kconfig.debug
Kconfig.i386 uml: keep UML Kconfig in sync with x86 2007-12-03 08:13:17 -08:00
Kconfig.net
Kconfig.x86_64
Makefile UML: build fix 2007-11-29 09:24:51 -08:00
Makefile-i386 no need to mess with KBUILD_CFLAGS on uml-i386 anymore 2007-12-05 09:25:20 -08:00
Makefile-ia64
Makefile-os-Linux
Makefile-ppc
Makefile-skas
Makefile-tt
Makefile-x86_64 x86 merge fallout: uml 2007-10-29 07:41:32 -07:00