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Diffstat (limited to 'sys/miscfs/procfs/README')
| -rw-r--r-- | sys/miscfs/procfs/README | 113 |
1 files changed, 0 insertions, 113 deletions
diff --git a/sys/miscfs/procfs/README b/sys/miscfs/procfs/README deleted file mode 100644 index f816b32..0000000 --- a/sys/miscfs/procfs/README +++ /dev/null @@ -1,113 +0,0 @@ -saute procfs lyonnais - -procfs supports two levels of directory. the filesystem root -directory contains a representation of the system process table. -this consists of an entry for each active and zombie process, and -an additional entry "curproc" which always represents the process -making the lookup request. - -each of the sub-directories contains several files. these files -are used to control and interrogate processes. the files implemented -are: - - file - xxx. the exec'ed file. - - status - r/o. returns process status. - - ctl - w/o. sends a control message to the process. - for example: - echo hup > /proc/curproc/note - will send a SIGHUP to the shell. - whereas - echo attach > /proc/1293/ctl - would set up process 1293 for debugging. - see below for more details. - - mem - r/w. virtual memory image of the process. - parts of the address space are readable - only if they exist in the target process. - a more reasonable alternative might be - to return zero pages instead of an error. - comments? - - note - w/o. writing a string here sends the - equivalent note to the process. - [ not implemented. ] - - notepg - w/o. the same as note, but sends to all - members of the process group. - [ not implemented. ] - - regs - r/w. process register set. this can be read - or written any time even if the process - is not stopped. since the bsd kernel - is single-processor, this implementation - will get the "right" register values. - a multi-proc kernel would need to do some - synchronisation. - -this then looks like: - -% ls -li /proc -total 0 - 9 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 0 - 17 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 1 - 89 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 10 - 25 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 2 -2065 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 257 -2481 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 309 - 265 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 32 -3129 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 390 -3209 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 400 -3217 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 401 -3273 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 408 - 393 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 48 - 409 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 50 - 465 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 57 - 481 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 59 - 537 dr-xr-xr-x 2 root kmem 0 Sep 21 15:06 66 - 545 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 67 - 657 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 81 - 665 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 82 - 673 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 83 - 681 dr-xr-xr-x 2 root wheel 0 Sep 21 15:06 84 -3273 dr-xr-xr-x 2 jsp staff 0 Sep 21 15:06 curproc -% ls -li /proc/curproc -total 408 -3341 --w------- 1 jsp staff 0 Sep 21 15:06 ctl -1554 -r-xr-xr-x 1 bin bin 90112 Mar 29 04:52 file -3339 -rw------- 1 jsp staff 118784 Sep 21 15:06 mem -3343 --w------- 1 jsp staff 0 Sep 21 15:06 note -3344 --w------- 1 jsp staff 0 Sep 21 15:06 notepg -3340 -rw------- 1 jsp staff 0 Sep 21 15:06 regs -3342 -r--r--r-- 1 jsp staff 0 Sep 21 15:06 status -% df /proc/curproc /proc/curproc/file -Filesystem 512-blocks Used Avail Capacity Mounted on -proc 2 2 0 100% /proc -/dev/wd0a 16186 13548 1018 93% / -% cat /proc/curproc/status -cat 446 439 400 81 12,0 ctty 748620684 270000 0 0 0 20000 nochan 11 20 20 20 0 21 117 - - - -the basic sequence of commands written to "ctl" would be - - attach - this stops the target process and - arranges for the sending process - to become the debug control process - wait - wait for the target process to come to - a steady state ready for debugging. - step - single step, with no signal delivery. - run - continue running, with no signal delivery, - until next trap or breakpoint. - <signame> - deliver signal <signame> and continue running. - detach - continue execution of the target process - and remove it from control by the debug process - -in a normal debugging environment, where the target is fork/exec'd by -the debugger, the debugger should fork and the child should stop itself -(with a self-inflicted SIGSTOP). the parent should do a "wait" then an -"attach". as before, the child will hit a breakpoint on the first -instruction in any newly exec'd image. - -$FreeBSD$ |
