diff options
| author | Denys Vlasenko <vda.linux@googlemail.com> | 2012-03-23 23:02:41 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-24 00:58:40 +0100 |
| commit | 86b6c1f301faf085de5a3f9ce16b8de6e69c729b (patch) | |
| tree | 115a168d533a54f4e3dc1ed195c58b65a71d8627 /kernel | |
| parent | ptrace: don't modify flags on PTRACE_SETOPTIONS failure (diff) | |
| download | linux-86b6c1f301faf085de5a3f9ce16b8de6e69c729b.tar.xz linux-86b6c1f301faf085de5a3f9ce16b8de6e69c729b.zip | |
ptrace: simplify PTRACE_foo constants and PTRACE_SETOPTIONS code
Exchange PT_TRACESYSGOOD and PT_PTRACE_CAP bit positions, which makes
PT_option bits contiguous and therefore makes code in
ptrace_setoptions() much simpler.
Every PTRACE_O_TRACEevent is defined to (1 << PTRACE_EVENT_event)
instead of using explicit numeric constants, to ensure we don't mess up
relationship between bit positions and event ids.
PT_EVENT_FLAG_SHIFT was not particularly useful, PT_OPT_FLAG_SHIFT with
value of PT_EVENT_FLAG_SHIFT-1 is easier to use.
PT_TRACE_MASK constant is nuked, the only its use is replaced by
(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT).
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/ptrace.c | 31 |
1 files changed, 8 insertions, 23 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 273f56ea39d2..9acd07a6f5bb 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -262,7 +262,7 @@ static int ptrace_attach(struct task_struct *task, long request, /* * Protect exec's credential calculations against our interference; - * interference; SUID, SGID and LSM creds get determined differently + * SUID, SGID and LSM creds get determined differently * under ptrace. */ retval = -ERESTARTNOINTR; @@ -528,31 +528,16 @@ int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long ds static int ptrace_setoptions(struct task_struct *child, unsigned long data) { + unsigned flags; + if (data & ~(unsigned long)PTRACE_O_MASK) return -EINVAL; - child->ptrace &= ~PT_TRACE_MASK; - - if (data & PTRACE_O_TRACESYSGOOD) - child->ptrace |= PT_TRACESYSGOOD; - - if (data & PTRACE_O_TRACEFORK) - child->ptrace |= PT_TRACE_FORK; - - if (data & PTRACE_O_TRACEVFORK) - child->ptrace |= PT_TRACE_VFORK; - - if (data & PTRACE_O_TRACECLONE) - child->ptrace |= PT_TRACE_CLONE; - - if (data & PTRACE_O_TRACEEXEC) - child->ptrace |= PT_TRACE_EXEC; - - if (data & PTRACE_O_TRACEVFORKDONE) - child->ptrace |= PT_TRACE_VFORK_DONE; - - if (data & PTRACE_O_TRACEEXIT) - child->ptrace |= PT_TRACE_EXIT; + /* Avoid intermediate state when all opts are cleared */ + flags = child->ptrace; + flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); + flags |= (data << PT_OPT_FLAG_SHIFT); + child->ptrace = flags; return 0; } |