linux-stable.git/arch/mips/kernel/ptrace.c, branch linux-3.2.y

MIPS: Prevent user from setting FCSR cause bits

2014-09-13T22:41:40+00:00

commit b1442d39fac2fcfbe6a4814979020e993ca59c9e upstream.

If one or more matching FCSR cause & enable bits are set in saved thread
context then when that context is restored the kernel will take an FP
exception. This is of course undesirable and considered an oops, leading
to the kernel writing a backtrace to the console and potentially
rebooting depending upon the configuration. Thus the kernel avoids this
situation by clearing the cause bits of the FCSR register when handling
FP exceptions and after emulating FP instructions.

However the kernel does not prevent userland from setting arbitrary FCSR
cause & enable bits via ptrace, using either the PTRACE_POKEUSR or
PTRACE_SETFPREGS requests. This means userland can trivially cause the
kernel to oops on any system with an FPU. Prevent this from happening
by clearing the cause bits when writing to the saved FCSR context via
ptrace.

This problem appears to exist at least back to the beginning of the git
era in the PTRACE_POKEUSR case.

Signed-off-by: Paul Burton 
Cc: linux-mips@linux-mips.org
Cc: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/7438/
Signed-off-by: Ralf Baechle 
Signed-off-by: Ben Hutchings

MIPS: Split do_syscall_trace into two functions.

2011-05-19T08:55:44+00:00

Signed-off-by: Ralf Baechle

MIPS: Audit: Fix success success argument pass to audit_syscall_exit

2011-05-10T17:15:25+00:00

Signed-off-by: Ralf Baechle

ptrace: cleanup arch_ptrace() on MIPS

2010-10-28T01:03:11+00:00

Use new 'addrp', 'datavp' and 'datalp' variables in order to remove
unnecessary castings.

Signed-off-by: Namhyung Kim 
Cc: Ralf Baechle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ptrace: change signature of arch_ptrace()

2010-10-28T01:03:10+00:00

Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.

Signed-off-by: Namhyung Kim 
Cc: 
Acked-by: Roland McGrath 
Acked-by: David Howells 
Acked-by: Geert Uytterhoeven 
Acked-by: David S. Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MIPS: secure_computing, syscall audit: syscall number should in r2, not r0.

2010-10-18T15:59:02+00:00

As it is, audit_syscall_entry() and secure_computing() get the
bogus value (0, in fact)

Signed-off-by: Al Viro 
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1697/
Signed-off-by: Ralf Baechle

mips: use generic ptrace_resume code

2010-03-12T23:52:39+00:00

Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT and
PTRACE_KILL.

Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.

Signed-off-by: Christoph Hellwig 
Cc: Oleg Nesterov 
Cc: Roland McGrath 
Acked-by: Ralf Baechle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MIPS: Ptrace support for HARDWARE_WATCHPOINTS

2008-10-11T15:18:57+00:00

This is the final part of the watch register patch.  Here we hook up
ptrace so that the user space debugger (gdb), can set and read the
registers.

Signed-off-by: David Daney 
Signed-off-by: Ralf Baechle

[MIPS] Build fix: Fix irq flags type

2008-10-03T16:58:56+00:00

Though from a hardware perspective it would be sensible to use only a
32-bit unsigned int type Linux defines interrupt flags to be stored in
an unsigned long and nothing else.

Signed-off-by: Ralf Baechle

[MIPS] Store sign-extend register values for PTRACE_GETREGS

2007-10-29T19:35:36+00:00

A comment on ptrace_getregs() states "Registers are sign extended to
fill the available space." but it is not true.  Fix code to match the
comment.  Also fix casts on each caller to get rid of some warnings.

Signed-off-by: Atsushi Nemoto 
Signed-off-by: Ralf Baechle