lkml.org 
[lkml]   [2011]   [Jun]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH 2/5] ptrace: implement PTRACE_SEIZE
    Date
    On Saturday 18 June 2011 09:55, Denys Vlasenko wrote:
    > On Tuesday 14 June 2011 11:20, Tejun Heo wrote:
    > #define PTRACE_EVENT_FORK 1
    > #define PTRACE_EVENT_VFORK 2
    > #define PTRACE_EVENT_CLONE 3
    > > #define PTRACE_EVENT_EXEC 4
    > > #define PTRACE_EVENT_VFORK_DONE 5
    > > #define PTRACE_EVENT_EXIT 6
    > > +#define PTRACE_EVENT_STOP 7
    >
    > Er... these constants were corresponding exactly to
    > bit positions in ptrace options which enable them:
    >
    > #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
    >
    > For example, PTRACE_O_TRACEEXEC is 4th bit, PTRACE_EVENT_EXEC is 4.
    >
    > If we'd define PTRACE_EVENT_STOP as 7, any future added
    > PTRACE_O_foo bit with value 0x00000080 will be unable
    > to follow this convention.
    >
    > I propose to define PTRACE_EVENT_STOP as 64 instead, leaving 64 low
    > PTRACE_EVENT_foo constants for possible future PTRACE_O_foo bits.
    >
    > [32 should be enough too, but I feel paranoid today :)]

    ...unless we plan to introduce PTRACE_O_TRACESTOP (with value 0x00000080)
    which enables PTRACE_INTERRUPT and stop notifications independently
    of PTRACE_SEIZE. Which would be very useful for e.g. strace.

    Then, PTRACE_EVENT_STOP indeed should be 7.

    --
    vda



    \
     
     \ /
      Last update: 2011-06-18 10:01    [W:0.023 / U:60.904 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site