There are possible race conditions if probes are placed on routines within the
kprobes files and routines used by the kprobes. For example if you put probe
on get_kprobe() routines, the system can hang while inserting probes on any
routine such as do_fork(). Because while inserting probes on do_fork(),
register_kprobes() routine grabs the kprobes spin lock and executes
get_kprobe() routine and to handle probe of get_kprobe(), kprobes_handler()
gets executed and tries to grab kprobes spin lock, and spins forever. This
patch avoids such possible race conditions by preventing probes on routines
within the kprobes file and routines used by kprobes.
I have modified the patches as per Andi Kleen's suggestion to move kprobes
routines and other routines used by kprobes to a seperate section
.kprobes.text.
Also moved page fault and exception handlers, general protection fault to
.kprobes.text section.
These patches have been tested on i386, x86_64 and ppc64 architectures, also
compiled on ia64 and sparc64 architectures.
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Several reports on inconsistent kallsyms data has been caused by the aliased symbols
__sched_text_start and __down to shift places in the output of nm.
The root cause was that on second pass ld aligned __sched_text_start to a 4 byte boundary
which is the function alignment on i386.
sched.text and spinlock.text is now aligned to an 8 byte boundary to make sure they
are aligned to a function alignemnt on most (all?) archs.
Tested by: Paulo Marques <pmarques@grupopie.com>
Tested by: Alexander Stohr <Alexander.Stohr@gmx.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
In vmlinux.lds.h the code is carefull to define every section so vmlinux
properly reports the correct physical load address of code, as well as
it's virtual address.
The new SECURITY_INIT definition fails to follow that convention and
and causes incorrect physical address to appear in the vmlinux if
there are any security initcalls.
This patch updates the SECURITY_INIT to follow the convention in the rest of
the file.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Prasanna S Panchamukhi