Patch from Nikola Valerjev
Single stepping an application using ptrace() fails over ARM instructions BX and BLX.
Steps to reproduce:
Compile and link the following files
main.c
-----
void foo();
int main() {
foo();
return 0;
}
foo.s
-----
.text
.globl foo
foo:
BX LR
Using ptrace() functionality, run to main(), and start singlestepping.
Singlestep over \"BX LR\" instruction won\'t transfer the control back
to main, but run the code to completion.
This problems seems to be in the function get_branch_address() in
arch/arm/kernel/ptrace.c. The function doesn\'t seem to recognize BX
and BLX instructions as branches. BX and BLX instructions can be used
to convert from ARM to Thumb mode if the target address has the low
bit set. However, they are also perfectly legal in the ARM only mode.
Although other things in the kernel seem to indicate that only ARM
mode is accepted (and not Thumb), many compilers will generate BX
and BLX instructions even when generating ARM only code.
Signed-off-by: Nikola Valerjev <nikola@ghs.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.
Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations. For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-By: David Howells <dhowells@redhat.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make sure we always return, as all syscalls should. Also move the common
prototype to <linux/syscalls.h>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert most of the current code that uses _NSIG directly to instead use
valid_signal(). This avoids gcc -W warnings and off-by-one errors.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
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!
