pmap: new applet. +1k.

pmap is a tool used to look at processes' memory maps, normally found
in procps package. It provides more readable and easily sortable output
(one line per mapping) from  maps/smaps files in /proc/PID/.  This would
help in debugging memory usage issues, especially on devices where lots
of typing is not a viable option.

This patch does'n implement -d and -A command line options of GNU pmap,
since those are not that must have features and I was afraid of going
blind from looking at its code.

The implementation takes smaps scanning part out of procps_scan() function
and moves it into procps_read_smaps(), which does more detailed processing
of a single PID's smaps data.

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

4 files changed, 251 insertions, 67 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 3fd754511..43e525cb9 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1387,6 +1387,29 @@ enum { COMM_LEN = TASK_COMM_LEN };
 enum { COMM_LEN = 16 };
 # endif
 #endif
+
+struct smaprec {
+        unsigned long mapped_rw;
+        unsigned long mapped_ro;
+        unsigned long shared_clean;
+        unsigned long shared_dirty;
+        unsigned long private_clean;
+        unsigned long private_dirty;
+        unsigned long stack;
+        unsigned long smap_pss, smap_swap;
+        unsigned long smap_size;
+        unsigned long smap_start;
+        char smap_mode[5];
+        char *smap_name;
+};
+
+#if !ENABLE_PMAP
+#define procps_read_smaps(pid, total, cb, data) \
+        procps_read_smaps(pid, total)
+#endif
+int FAST_FUNC procps_read_smaps(pid_t pid, struct smaprec *total,
+                      void (*cb)(struct smaprec *, void *), void *data);
+
 typedef struct procps_status_t {
         DIR *dir;
         IF_FEATURE_SHOW_THREADS(DIR *task_dir;)
@@ -1415,13 +1438,7 @@ typedef struct procps_status_t {
 #endif
         unsigned tty_major,tty_minor;
 #if ENABLE_FEATURE_TOPMEM
-        unsigned long mapped_rw;
-        unsigned long mapped_ro;
-        unsigned long shared_clean;
-        unsigned long shared_dirty;
-        unsigned long private_clean;
-        unsigned long private_dirty;
-        unsigned long stack;
+        struct smaprec smaps;
 #endif
         char state[4];
         /* basename of executable in exec(2), read from /proc/N/stat
diff --git a/libbb/procps.c b/libbb/procps.c
index 16992b670..14d4481bd 100644
--- a/libbb/procps.c
+++ b/libbb/procps.c
@@ -137,12 +137,9 @@ static unsigned long fast_strtoul_16(char **endptr)
         *endptr = str; /* We skip trailing space! */
         return n;
 }
-/* TOPMEM uses fast_strtoul_10, so... */
-# undef ENABLE_FEATURE_FAST_TOP
-# define ENABLE_FEATURE_FAST_TOP 1
 #endif
 
-#if ENABLE_FEATURE_FAST_TOP
+#if ENABLE_FEATURE_FAST_TOP || ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
 /* We cut a lot of corners here for speed */
 static unsigned long fast_strtoul_10(char **endptr)
 {
@@ -177,6 +174,111 @@ static char *skip_fields(char *str, int count)
 }
 #endif
 
+#if ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
+int FAST_FUNC procps_read_smaps(pid_t pid, struct smaprec *total,
+                      void (*cb)(struct smaprec *, void *), void *data)
+{
+        FILE *file;
+        struct smaprec currec;
+        char filename[sizeof("/proc/%u/smaps") + sizeof(int)*3];
+        char buf[PROCPS_BUFSIZE];
+#if !ENABLE_PMAP
+        void (*cb)(struct smaprec *, void *) = NULL;
+        void *data = NULL;
+#endif
+
+        sprintf(filename, "/proc/%u/smaps", (int)pid);
+
+        file = fopen_for_read(filename);
+        if (!file)
+                return 1;
+
+        memset(&currec, 0, sizeof(currec));
+        while (fgets(buf, PROCPS_BUFSIZE, file)) {
+                // Each mapping datum has this form:
+                // f7d29000-f7d39000 rw-s ADR M:m OFS FILE
+                // Size:                nnn kB
+                // Rss:                 nnn kB
+                // .....
+
+                char *tp = buf, *p;
+
+#define SCAN(S, X) \
+                if (strncmp(tp, S, sizeof(S)-1) == 0) {              \
+                        tp = skip_whitespace(tp + sizeof(S)-1);      \
+                        total->X += currec.X = fast_strtoul_10(&tp); \
+                        continue;                                    \
+                }
+                if (cb) {
+                        SCAN("Pss:"  , smap_pss     );
+                        SCAN("Swap:" , smap_swap    );
+                }
+                SCAN("Private_Dirty:", private_dirty);
+                SCAN("Private_Clean:", private_clean);
+                SCAN("Shared_Dirty:" , shared_dirty );
+                SCAN("Shared_Clean:" , shared_clean );
+#undef SCAN
+                tp = strchr(buf, '-');
+                if (tp) {
+                        // We reached next mapping - the line of this form:
+                        // f7d29000-f7d39000 rw-s ADR M:m OFS FILE
+
+                        if (cb) {
+                                /* If we have a previous record, there's nothing more
+                                 * for it, call the callback and clear currec
+                                 */
+                                if (currec.smap_size)
+                                        cb(&currec, data);
+                                free(currec.smap_name);
+                        }
+                        memset(&currec, 0, sizeof(currec));
+
+                        *tp = ' ';
+                        tp = buf;
+                        currec.smap_start = fast_strtoul_16(&tp);
+                        currec.smap_size = (fast_strtoul_16(&tp) - currec.smap_start) >> 10;
+
+                        strncpy(currec.smap_mode, tp, sizeof(currec.smap_mode)-1);
+
+                        // skipping "rw-s ADR M:m OFS "
+                        tp = skip_whitespace(skip_fields(tp, 4));
+                        // filter out /dev/something (something != zero)
+                        if (strncmp(tp, "/dev/", 5) != 0 || strcmp(tp, "/dev/zero\n") == 0) {
+                                if (currec.smap_mode[1] == 'w') {
+                                        currec.mapped_rw = currec.smap_size;
+                                        total->mapped_rw += currec.smap_size;
+                                } else if (currec.smap_mode[1] == '-') {
+                                        currec.mapped_ro = currec.smap_size;
+                                        total->mapped_ro += currec.smap_size;
+                                }
+                        }
+
+                        if (strcmp(tp, "[stack]\n") == 0)
+                                total->stack += currec.smap_size;
+                        if (cb) {
+                                p = skip_non_whitespace(tp);
+                                if (p == tp) {
+                                        currec.smap_name = xstrdup("  [ anon ]");
+                                } else {
+                                        *p = '\0';
+                                        currec.smap_name = xstrdup(tp);
+                                }
+                        }
+                        total->smap_size += currec.smap_size;
+                }
+        }
+        fclose(file);
+
+        if (cb) {
+                if (currec.smap_size)
+                        cb(&currec, data);
+                free(currec.smap_name);
+        }
+
+        return 0;
+}
+#endif
+
 void BUG_comm_size(void);
 procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
 {
@@ -365,54 +467,8 @@ procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
                 }
 
 #if ENABLE_FEATURE_TOPMEM
-                if (flags & (PSSCAN_SMAPS)) {
-                        FILE *file;
-
-                        strcpy(filename_tail, "smaps");
-                        file = fopen_for_read(filename);
-                        if (file) {
-                                while (fgets(buf, sizeof(buf), file)) {
-                                        unsigned long sz;
-                                        char *tp;
-                                        char w;
-#define SCAN(str, name) \
-        if (strncmp(buf, str, sizeof(str)-1) == 0) { \
-                tp = skip_whitespace(buf + sizeof(str)-1); \
-                sp->name += fast_strtoul_10(&tp); \
-                continue; \
-        }
-                                        SCAN("Shared_Clean:" , shared_clean );
-                                        SCAN("Shared_Dirty:" , shared_dirty );
-                                        SCAN("Private_Clean:", private_clean);
-                                        SCAN("Private_Dirty:", private_dirty);
-#undef SCAN
-                                        // f7d29000-f7d39000 rw-s ADR M:m OFS FILE
-                                        tp = strchr(buf, '-');
-                                        if (tp) {
-                                                *tp = ' ';
-                                                tp = buf;
-                                                sz = fast_strtoul_16(&tp); /* start */
-                                                sz = (fast_strtoul_16(&tp) - sz) >> 10; /* end - start */
-                                                // tp -> "rw-s" string
-                                                w = tp[1];
-                                                // skipping "rw-s ADR M:m OFS "
-                                                tp = skip_whitespace(skip_fields(tp, 4));
-                                                // filter out /dev/something (something != zero)
-                                                if (strncmp(tp, "/dev/", 5) != 0 || strcmp(tp, "/dev/zero\n") == 0) {
-                                                        if (w == 'w') {
-                                                                sp->mapped_rw += sz;
-                                                        } else if (w == '-') {
-                                                                sp->mapped_ro += sz;
-                                                        }
-                                                }
-//else printf("DROPPING %s (%s)\n", buf, tp);
-                                                if (strcmp(tp, "[stack]\n") == 0)
-                                                        sp->stack += sz;
-                                        }
-                                }
-                                fclose(file);
-                        }
-                }
+                if (flags & PSSCAN_SMAPS)
+                        procps_read_smaps(pid, &sp->smaps, NULL, NULL);
 #endif /* TOPMEM */
 #if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
                 if (flags & PSSCAN_RUIDGID) {
diff --git a/procps/pmap.c b/procps/pmap.c
new file mode 100644
index 000000000..cfa94ed82
--- /dev/null
+++ b/procps/pmap.c
@@ -0,0 +1,111 @@
+/*
+ * pmap implementation for busybox
+ *
+ * Copyright (C) 2010 Nokia Corporation. All rights reserved.
+ * Written by Alexander Shishkin <virtuoso@slind.org>
+ *
+ * Licensed under GPLv2 or later, see the LICENSE file in this source tree
+ * for details.
+ */
+
+//applet:IF_PMAP(APPLET(pmap, _BB_DIR_USR_BIN, _BB_SUID_DROP))
+//kbuild:lib-$(CONFIG_PMAP)     += pmap.o
+
+//config:config PMAP
+//config:       bool "pmap"
+//config:       default y
+//config:       help
+//config:         Display processes' memory mappings.
+
+//usage:#define pmap_trivial_usage
+//usage:       "[-x][-q] PID"
+//usage:#define pmap_full_usage "\n\n"
+//usage:       "Display detailed precesses' memory usage\n"
+//usage:       "\nOptions:"
+//usage:       "\n     -x              show details"
+//usage:       "\n     -q              quiet"
+
+#include "libbb.h"
+
+#if ULONG_MAX == 0xffffffff
+# define TABS "\t"
+# define AFMT "8"
+# define DASHES ""
+#else
+# define TABS "\t\t"
+# define AFMT "16"
+# define DASHES "--------"
+#endif
+
+enum {
+        OPT_x = 1 << 0,
+        OPT_q = 1 << 1,
+};
+
+static void print_smaprec(struct smaprec *currec, void *data)
+{
+        unsigned opt = (unsigned)data;
+
+        printf("%0" AFMT "lx ", currec->smap_start);
+
+        if (opt & OPT_x)
+                printf("%7lu %7lu %7lu %7lu ",
+                        currec->smap_size,
+                        currec->smap_pss,
+                        currec->private_dirty,
+                        currec->smap_swap);
+        else
+                printf("%7luK", currec->smap_size);
+
+        printf(" %.4s  %s\n", currec->smap_mode, currec->smap_name);
+}
+
+static int procps_get_maps(pid_t pid, unsigned opt)
+{
+        struct smaprec total;
+        int ret;
+        char buf[256];
+
+        read_cmdline(buf, sizeof(buf), pid, "no such process");
+        printf("%u: %s\n", (int)pid, buf);
+
+        if (!(opt & OPT_q) && (opt & OPT_x))
+                puts("Address" TABS "  Kbytes     PSS   Dirty    Swap  Mode  Mapping");
+
+        memset(&total, 0, sizeof(total));
+
+        ret = procps_read_smaps(pid, &total, print_smaprec, (void*)opt);
+        if (ret)
+                return ret;
+
+        if (!(opt & OPT_q)) {
+                if (opt & OPT_x)
+                        printf("--------" DASHES "  ------  ------  ------  ------\n"
+                                "total" TABS " %7lu %7lu %7lu %7lu\n",
+                                total.smap_size, total.smap_pss, total.private_dirty, total.smap_swap);
+                else
+                        printf("mapped: %luK\n", total.smap_size);
+        }
+
+        return 0;
+}
+
+int pmap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int pmap_main(int argc UNUSED_PARAM, char **argv)
+{
+        unsigned opts;
+        int ret;
+
+        opts = getopt32(argv, "xq");
+        argv += optind;
+
+        ret = 0;
+        while (*argv) {
+                pid_t pid = xatoi_positive(*argv++);
+                /* GNU pmap returns 42 if any of the pids failed */
+                if (procps_get_maps(pid, opts) != 0)
+                        ret = 42;
+        }
+
+        return ret;
+}
diff --git a/procps/top.c b/procps/top.c
index fd758099e..4f37878de 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -942,20 +942,20 @@ int top_main(int argc UNUSED_PARAM, char **argv)
                         }
 #if ENABLE_FEATURE_TOPMEM
                         else { /* TOPMEM */
-                                if (!(p->mapped_ro | p->mapped_rw))
+                                if (!(p->smaps.mapped_ro | p->smaps.mapped_rw))
                                         continue; /* kernel threads are ignored */
                                 n = ntop;
                                 /* No bug here - top and topmem are the same */
                                 top = xrealloc_vector(topmem, 6, ntop++);
                                 strcpy(topmem[n].comm, p->comm);
                                 topmem[n].pid      = p->pid;
-                                topmem[n].vsz      = p->mapped_rw + p->mapped_ro;
-                                topmem[n].vszrw    = p->mapped_rw;
-                                topmem[n].rss_sh   = p->shared_clean + p->shared_dirty;
-                                topmem[n].rss      = p->private_clean + p->private_dirty + topmem[n].rss_sh;
-                                topmem[n].dirty    = p->private_dirty + p->shared_dirty;
-                                topmem[n].dirty_sh = p->shared_dirty;
-                                topmem[n].stack    = p->stack;
+                                topmem[n].vsz      = p->smaps.mapped_rw + p->smaps.mapped_ro;
+                                topmem[n].vszrw    = p->smaps.mapped_rw;
+                                topmem[n].rss_sh   = p->smaps.shared_clean + p->smaps.shared_dirty;
+                                topmem[n].rss      = p->smaps.private_clean + p->smaps.private_dirty + topmem[n].rss_sh;
+                                topmem[n].dirty    = p->smaps.private_dirty + p->smaps.shared_dirty;
+                                topmem[n].dirty_sh = p->smaps.shared_dirty;
+                                topmem[n].stack    = p->smaps.stack;
                         }
 #endif
                 } /* end of "while we read /proc" */