Commit Graph

5 Commits

Author SHA1 Message Date
Jason Wessel
d7161a6534 kgdb, x86, arm, mips, powerpc: ignore user space single stepping
On the x86 arch, user space single step exceptions should be ignored
if they occur in the kernel space, such as ptrace stepping through a
system call.

First check if it is kgdb that is executing a single step, then ensure
it is not an accidental traversal into the user space, while in kgdb,
any other time the TIF_SINGLESTEP is set, kgdb should ignore the
exception.

On x86, arm, mips and powerpc, the kgdb_contthread usage was
inconsistent with the way single stepping is implemented in the kgdb
core.  The arch specific stub should always set the
kgdb_cpu_doing_single_step correctly if it is single stepping.  This
allows kgdb to correctly process an instruction steps if ptrace
happens to be requesting an instruction step over a system call.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2008-09-26 10:36:41 -05:00
Atsushi Nemoto
b895760dfb [MIPS] kgdb: Do not call fixup_exception
kgdb_mips_notify is called on IBE/DBE/FPE/BP/TRAP/RI exception.  None
of them need fixup.  And doing fixup for a breakpoint exception will
confuse gdb.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-08-26 09:10:26 +01:00
Ralf Baechle
9391d6bbed [MIPS] kgdb: s/(void *)0)/NULL/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-08-26 09:10:24 +01:00
Ralf Baechle
e522b7ccd2 [MIPS] kgdb: smp_call_function's 3rd argument is a pointer.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-08-26 09:10:23 +01:00
Jason Wessel
8854700115 [MIPS] kgdb: add arch support for the kernel's kgdb core
The new kgdb architecture specific handler registers and unregisters
dynamically for exceptions depending on when you configure a kgdb I/O
driver.

Aside from initializing the exceptions earlier in the boot process,
kgdb should have no impact on a device when it is compiled in so long
as an I/O module is not configured for use.

There have been quite a number of contributors during the existence of
this patch (see arch/mips/kernel/kgdb.c).  Most recently Jason
re-wrote the mips kgdb logic to use the die notification handlers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-07-30 21:54:42 +01:00