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>

1 files changed, 111 insertions, 0 deletions

diff --git a/procps/pmap.c b/procps/pmap.c
new file mode 100644
index 0000000..cfa94ed
--- /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;
+}