Messages in this thread Patch in this message | | | Date | Sat, 09 Oct 2021 12:07:57 +0200 | From | Peter Zijlstra <> | Subject | [PATCH v3 3/6] ptrace: Order and comment PT_flags |
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Add a comment to the PT_flags to indicate their actual value, this makes it easier to see what bits are used and where there might be a possible hole to use.
Notable PT_SEIZED was placed wrong, also PT_EVENT_FLAG() space seems ill defined, as written is seems to be meant to cover the entire PTRACE_O_ range offset by 3 bits, which would then be 3+[0..21], however PT_SEIZED is in the middle of that.
XXX if at all possible, PT_SEIZED should be moved outside of this range.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- include/linux/ptrace.h | 32 +++++++++++++++++--------------- include/uapi/linux/ptrace.h | 3 +++ 2 files changed, 20 insertions(+), 15 deletions(-)
--- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -28,30 +28,32 @@ extern int ptrace_access_vm(struct task_ * flags. When the a task is stopped the ptracer owns task->ptrace. */ -#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_PTRACED 0x00000001 // 0x00000001 +#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ // 0x00000002 #define PT_OPT_FLAG_SHIFT 3 /* PT_TRACE_* event enable flags */ #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) -#define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) -#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_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP) -#define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) -#define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT) +#define PT_TRACESYSGOOD PT_EVENT_FLAG(0) // 0x00000008 +#define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) // 0x00000010 +#define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) // 0x00000020 +#define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) // 0x00000040 +#define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) // 0x00000080 +#define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) // 0x00000100 +#define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) // 0x00000200 +#define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP) // 0x00000400 + +#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */// 0x00010000 + +#define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) // 0x00800000 +#define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT) // 0x01000000 /* single stepping state bits (used on ARM and PA-RISC) */ #define PT_SINGLESTEP_BIT 31 -#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) +#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) // 0x80000000 #define PT_BLOCKSTEP_BIT 30 -#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) +#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) // 0x40000000 extern long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data); --- a/include/uapi/linux/ptrace.h +++ b/include/uapi/linux/ptrace.h @@ -134,6 +134,7 @@ struct ptrace_rseq_configuration { #define PTRACE_EVENT_STOP 128 /* Options set using PTRACE_SETOPTIONS or using PTRACE_SEIZE @data param */ +/* Consider overlap with task->ptrace PT_flags */ #define PTRACE_O_TRACESYSGOOD 1 #define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK) #define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK) @@ -143,6 +144,8 @@ struct ptrace_rseq_configuration { #define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT) #define PTRACE_O_TRACESECCOMP (1 << PTRACE_EVENT_SECCOMP) +/* PTRACE_O_SEIZED (1 << 13) */ + /* eventless options */ #define PTRACE_O_EXITKILL (1 << 20) #define PTRACE_O_SUSPEND_SECCOMP (1 << 21)
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