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author | Denys Vlasenko <vda.linux@googlemail.com> | 2012-03-23 15:02:41 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-23 16:58:40 -0700 |
commit | 86b6c1f301faf085de5a3f9ce16b8de6e69c729b (patch) | |
tree | 115a168d533a54f4e3dc1ed195c58b65a71d8627 | |
parent | 8c5cf9e5c50dc902713897e10201aa71f3546aa1 (diff) | |
download | linux-stable-86b6c1f301faf085de5a3f9ce16b8de6e69c729b.tar.gz linux-stable-86b6c1f301faf085de5a3f9ce16b8de6e69c729b.tar.bz2 linux-stable-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>
-rw-r--r-- | include/linux/ptrace.h | 33 | ||||
-rw-r--r-- | kernel/ptrace.c | 31 |
2 files changed, 23 insertions, 41 deletions
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 6fdb196caa3e..6f1260ee5be5 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -54,17 +54,6 @@ /* flags in @data for PTRACE_SEIZE */ #define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */ -/* options set using PTRACE_SETOPTIONS */ -#define PTRACE_O_TRACESYSGOOD 0x00000001 -#define PTRACE_O_TRACEFORK 0x00000002 -#define PTRACE_O_TRACEVFORK 0x00000004 -#define PTRACE_O_TRACECLONE 0x00000008 -#define PTRACE_O_TRACEEXEC 0x00000010 -#define PTRACE_O_TRACEVFORKDONE 0x00000020 -#define PTRACE_O_TRACEEXIT 0x00000040 - -#define PTRACE_O_MASK 0x0000007f - /* Wait extended result codes for the above trace options. */ #define PTRACE_EVENT_FORK 1 #define PTRACE_EVENT_VFORK 2 @@ -74,6 +63,17 @@ #define PTRACE_EVENT_EXIT 6 #define PTRACE_EVENT_STOP 7 +/* options set using PTRACE_SETOPTIONS */ +#define PTRACE_O_TRACESYSGOOD 1 +#define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK) +#define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK) +#define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE) +#define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC) +#define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE) +#define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT) + +#define PTRACE_O_MASK 0x0000007f + #include <asm/ptrace.h> #ifdef __KERNEL__ @@ -88,13 +88,12 @@ #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ #define PT_PTRACED 0x00000001 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ -#define PT_TRACESYSGOOD 0x00000004 -#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */ +#define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */ +#define PT_OPT_FLAG_SHIFT 3 /* PT_TRACE_* event enable flags */ -#define PT_EVENT_FLAG_SHIFT 4 -#define PT_EVENT_FLAG(event) (1 << (PT_EVENT_FLAG_SHIFT + (event) - 1)) - +#define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) +#define PT_TRACESYSGOOD PT_EVENT_FLAG(0) #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) @@ -102,8 +101,6 @@ #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) -#define PT_TRACE_MASK 0x000003f4 - /* single stepping state bits (used on ARM and PA-RISC) */ #define PT_SINGLESTEP_BIT 31 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) 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; } |