minix/servers/procfs/pid.c
David van Moolenbroek 595d73a896 PM: rework signal handling
- introduce PROC_STOPPED flag, which tracks whether the process is
  stopped on PROC_STOP in the kernel, rather than implicitly deriving
  this from PM_SIG_PENDING;
- make the process resumption test based on current state rather than
  state transitions;
- add and clarify several flag checks in the signal handling code;
- add test79 to test signal handling robustness.

Change-Id: Ic8c7527095035b300b56f2ab1b9dd190bd4bf001
2014-03-01 09:04:59 +01:00

380 lines
10 KiB
C

/* ProcFS - pid.c - by Alen Stojanov and David van Moolenbroek */
#include "inc.h"
#include <sys/mman.h>
#include <minix/vm.h>
#define S_FRAME_SIZE 4096 /* use malloc if larger than this */
static char s_frame[S_FRAME_SIZE]; /* static storage for process frame */
static char *frame; /* pointer to process frame buffer */
static void pid_psinfo(int slot);
static void pid_cmdline(int slot);
static void pid_environ(int slot);
static void pid_map(int slot);
/* The files that are dynamically created in each PID directory. The data field
* contains each file's read function. Subdirectories are not yet supported.
*/
struct file pid_files[] = {
{ "psinfo", REG_ALL_MODE, (data_t) pid_psinfo },
{ "cmdline", REG_ALL_MODE, (data_t) pid_cmdline },
{ "environ", REG_ALL_MODE, (data_t) pid_environ },
{ "map", REG_ALL_MODE, (data_t) pid_map },
{ NULL, 0, (data_t) NULL }
};
/*===========================================================================*
* is_zombie *
*===========================================================================*/
static int is_zombie(int slot)
{
/* Is the given slot a zombie process?
*/
return (slot >= NR_TASKS &&
(mproc[slot - NR_TASKS].mp_flags & (TRACE_ZOMBIE | ZOMBIE)));
}
/*===========================================================================*
* pid_psinfo *
*===========================================================================*/
static void pid_psinfo(int i)
{
/* Print information used by ps(1) and top(1).
*/
int pi, task, state, type, p_state, f_state;
char name[PROC_NAME_LEN+1], *p;
struct vm_usage_info vui;
pid_t ppid;
pi = i - NR_TASKS;
task = proc[i].p_nr < 0;
/* Get the name of the process. Spaces would mess up the format.. */
if (task || mproc[i].mp_name[0] == 0)
strncpy(name, proc[i].p_name, sizeof(name) - 1);
else
strncpy(name, mproc[pi].mp_name, sizeof(name) - 1);
name[sizeof(name) - 1] = 0;
if ((p = strchr(name, ' ')) != NULL)
p[0] = 0;
/* Get the type of the process. */
if (task)
type = TYPE_TASK;
else if (mproc[i].mp_flags & PRIV_PROC)
type = TYPE_SYSTEM;
else
type = TYPE_USER;
/* Get the state of the process. */
if (!task) {
if (is_zombie(i))
state = STATE_ZOMBIE; /* zombie */
else if (mproc[pi].mp_flags & TRACE_STOPPED)
state = STATE_STOP; /* stopped (traced) */
else if (proc[i].p_rts_flags == 0)
state = STATE_RUN; /* in run-queue */
else if (fp_is_blocked(&fproc[pi]) ||
(mproc[pi].mp_flags & (WAITING | SIGSUSPENDED)))
state = STATE_SLEEP; /* sleeping */
else
state = STATE_WAIT; /* waiting */
} else {
if (proc[i].p_rts_flags == 0)
state = STATE_RUN; /* in run-queue */
else
state = STATE_WAIT; /* other i.e. waiting */
}
/* We assume that even if a process has become a zombie, its kernel
* proc entry still contains the old (but valid) information. Currently
* this is true, but in the future we may have to filter some fields.
*/
buf_printf("%d %c %d %s %c %d %d %lu %lu %lu %lu",
PSINFO_VERSION, /* information version */
type, /* process type */
(int) proc[i].p_endpoint, /* process endpoint */
name, /* process name */
state, /* process state letter */
(int) P_BLOCKEDON(&proc[i]), /* endpt blocked on, or NONE */
(int) proc[i].p_priority, /* process priority */
(long) proc[i].p_user_time, /* user time */
(long) proc[i].p_sys_time, /* system time */
ex64hi(proc[i].p_cycles), /* execution cycles */
ex64lo(proc[i].p_cycles)
);
memset(&vui, 0, sizeof(vui));
if (!is_zombie(i)) {
/* We don't care if this fails. */
(void) vm_info_usage(proc[i].p_endpoint, &vui);
}
/* If the process is not a kernel task, we add some extra info. */
if (!task) {
if (mproc[pi].mp_flags & WAITING)
p_state = PSTATE_WAITING;
else if (mproc[pi].mp_flags & SIGSUSPENDED)
p_state = PSTATE_SIGSUSP;
else
p_state = '-';
if (mproc[pi].mp_parent == pi)
ppid = NO_PID;
else
ppid = mproc[mproc[pi].mp_parent].mp_pid;
switch (fproc[pi].fp_blocked_on) {
case FP_BLOCKED_ON_NONE: f_state = FSTATE_NONE; break;
case FP_BLOCKED_ON_PIPE: f_state = FSTATE_PIPE; break;
case FP_BLOCKED_ON_LOCK: f_state = FSTATE_LOCK; break;
case FP_BLOCKED_ON_POPEN: f_state = FSTATE_POPEN; break;
case FP_BLOCKED_ON_SELECT: f_state = FSTATE_SELECT; break;
case FP_BLOCKED_ON_OTHER: f_state = FSTATE_TASK; break;
default: f_state = FSTATE_UNKNOWN;
}
buf_printf(" %lu %lu %lu %c %d %u %u %u %d %c %d %u",
vui.vui_total, /* total memory */
vui.vui_common, /* common memory */
vui.vui_shared, /* shared memory */
p_state, /* sleep state */
ppid, /* parent PID */
mproc[pi].mp_realuid, /* real UID */
mproc[pi].mp_effuid, /* effective UID */
mproc[pi].mp_procgrp, /* process group */
mproc[pi].mp_nice, /* nice value */
f_state, /* VFS block state */
(int) (fproc[pi].fp_blocked_on == FP_BLOCKED_ON_OTHER)
? fproc[pi].fp_task : NONE, /* block proc */
fproc[pi].fp_tty /* controlling tty */
);
}
/* always add kernel cycles */
buf_printf(" %lu %lu %lu %lu",
ex64hi(proc[i].p_kipc_cycles),
ex64lo(proc[i].p_kipc_cycles),
ex64hi(proc[i].p_kcall_cycles),
ex64lo(proc[i].p_kcall_cycles));
/* add total memory for tasks at the end */
if(task) buf_printf(" %lu", vui.vui_total);
/* Newline at the end of the file. */
buf_printf("\n");
}
/*===========================================================================*
* put_frame *
*===========================================================================*/
static void put_frame(void)
{
/* If we allocated memory dynamically during a call to get_frame(),
* free it up here.
*/
if (frame != s_frame)
free(frame);
}
/*===========================================================================*
* get_frame *
*===========================================================================*/
static int get_frame(int slot, vir_bytes *basep, vir_bytes *sizep,
size_t *nargsp)
{
/* Get the execution frame from the top of the given process's stack.
* It may be very large, in which case we temporarily allocate memory
* for it (up to a certain size).
*/
vir_bytes base, size;
size_t nargs;
if (proc[slot].p_nr < 0 || is_zombie(slot))
return FALSE;
/* Get the frame base address and size. Limit the size to whatever we
* can handle. If our static buffer is not sufficiently large to store
* the entire frame, allocate memory dynamically. It is then later
* freed by put_frame().
*/
base = mproc[slot - NR_TASKS].mp_frame_addr;
size = mproc[slot - NR_TASKS].mp_frame_len;
if (size < sizeof(size_t)) return FALSE;
if (size > ARG_MAX) size = ARG_MAX;
if (size > sizeof(s_frame)) {
frame = malloc(size);
if (frame == NULL)
return FALSE;
}
else frame = s_frame;
/* Copy in the complete process frame. */
if (sys_datacopy(proc[slot].p_endpoint, base,
SELF, (vir_bytes) frame, (phys_bytes) size) != OK) {
put_frame();
return FALSE;
}
frame[size] = 0; /* terminate any last string */
nargs = * (size_t *) frame;
if (nargs < 1 || sizeof(size_t) + sizeof(char *) * (nargs + 1) > size) {
put_frame();
return FALSE;
}
*basep = base;
*sizep = size;
*nargsp = nargs;
/* The caller now has to called put_frame() to clean up. */
return TRUE;
}
/*===========================================================================*
* pid_cmdline *
*===========================================================================*/
static void pid_cmdline(int slot)
{
/* Dump the process's command line as it is contained in the process
* itself. Each argument is terminated with a null character.
*/
vir_bytes base, size, ptr;
size_t i, len, nargs;
char **argv;
if (!get_frame(slot, &base, &size, &nargs))
return;
argv = (char **) &frame[sizeof(size_t)];
for (i = 0; i < nargs; i++) {
ptr = (vir_bytes) argv[i] - base;
/* Check for bad pointers. */
if ((long) ptr < 0L || ptr >= size)
break;
len = strlen(&frame[ptr]) + 1;
buf_append(&frame[ptr], len);
}
put_frame();
}
/*===========================================================================*
* pid_environ *
*===========================================================================*/
static void pid_environ(int slot)
{
/* Dump the process's initial environment as it is contained in the
* process itself. Each entry is terminated with a null character.
*/
vir_bytes base, size, ptr;
size_t nargs, off, len;
char **envp;
if (!get_frame(slot, &base, &size, &nargs))
return;
off = sizeof(size_t) + sizeof(char *) * (nargs + 1);
envp = (char **) &frame[off];
for (;;) {
/* Make sure there is no buffer overrun. */
if (off + sizeof(char *) > size)
break;
ptr = (vir_bytes) *envp;
/* Stop at the terminating NULL pointer. */
if (ptr == 0L)
break;
ptr -= base;
/* Check for bad pointers. */
if ((long) ptr < 0L || ptr >= size)
break;
len = strlen(&frame[ptr]) + 1;
buf_append(&frame[ptr], len);
off += sizeof(char *);
envp++;
}
put_frame();
}
/*===========================================================================*
* dump_regions *
*===========================================================================*/
static int dump_regions(int slot)
{
/* Print the virtual memory regions of a process.
*/
struct vm_region_info vri[MAX_VRI_COUNT];
vir_bytes next;
int i, r, count;
count = 0;
next = 0;
do {
r = vm_info_region(proc[slot].p_endpoint, vri, MAX_VRI_COUNT,
&next);
if (r < 0)
return r;
if (r == 0)
break;
for (i = 0; i < r; i++) {
buf_printf("%08lx-%08lx %c%c%c\n",
vri[i].vri_addr, vri[i].vri_addr + vri[i].vri_length,
(vri[i].vri_prot & PROT_READ) ? 'r' : '-',
(vri[i].vri_prot & PROT_WRITE) ? 'w' : '-',
(vri[i].vri_prot & PROT_EXEC) ? 'x' : '-');
count++;
}
} while (r == MAX_VRI_COUNT);
return count;
}
/*===========================================================================*
* pid_map *
*===========================================================================*/
static void pid_map(int slot)
{
/* Print a memory map of the process. Obtain the information from VM if
* possible; otherwise fall back on segments from the kernel.
*/
/* Zombies have no memory. */
if (is_zombie(slot))
return;
/* Kernel tasks also have no memory. */
if (proc[slot].p_nr >= 0) {
if (dump_regions(slot) != 0)
return;
}
}