ps: fix RSS parsing (rss field in /proc/PID/stat is in pages, not bytes)

2 files changed, 18 insertions, 7 deletions

diff --git a/include/libbb.h b/include/libbb.h
index e514fe2f2..89a1695fa 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -881,12 +881,12 @@ enum { COMM_LEN = TASK_COMM_LEN };
 enum { COMM_LEN = 16 };
 #endif
 #endif
-typedef struct {
+typedef struct procps_status_t {
         DIR *dir;
+        uint8_t shift_pages_to_bytes;
+        uint8_t shift_pages_to_kb;
 /* Fields are set to 0/NULL if failed to determine (or not requested) */
-        /*char *cmd;*/
         char *argv0;
-        /*char *exe;*/
         USE_SELINUX(char *context;)
         /* Everything below must contain no ptrs to malloc'ed data:
          * it is memset(0) for each process in procps_scan() */
diff --git a/libbb/procps.c b/libbb/procps.c
index aa207af6f..8d3aea332 100644
--- a/libbb/procps.c
+++ b/libbb/procps.c
@@ -95,8 +95,15 @@ static int read_to_buf(const char *filename, void *buf)
 
 procps_status_t *alloc_procps_scan(int flags)
 {
+        unsigned n = getpagesize();
         procps_status_t* sp = xzalloc(sizeof(procps_status_t));
         sp->dir = xopendir("/proc");
+        while (1) {
+                n >>= 1;
+                if (!n) break;
+                sp->shift_pages_to_bytes++;
+        }
+        sp->shift_pages_to_kb = sp->shift_pages_to_bytes - 10;
         return sp;
 }
 
@@ -229,8 +236,10 @@ procps_status_t *procps_scan(procps_status_t* sp, int flags)
                                 &rss);
                         if (n != 10)
                                 break;
-                        sp->vsz = vsz >> 10; /* vsize is in bytes and we want kb */
-                        sp->rss = rss >> 10;
+                        /* vsz is in bytes and we want kb */
+                        sp->vsz = vsz >> 10;
+                        /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
+                        sp->rss = rss << sp->shift_pages_to_kb;
                         sp->tty_major = (tty >> 8) & 0xfff;
                         sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
 #else
@@ -250,8 +259,10 @@ procps_status_t *procps_scan(procps_status_t* sp, int flags)
                         cp = skip_fields(cp, 3); /* cutime, cstime, priority */
                         tasknice = fast_strtoul_10(&cp);
                         cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
-                        sp->vsz = fast_strtoul_10(&cp) >> 10; /* vsize is in bytes and we want kb */
-                        sp->rss = fast_strtoul_10(&cp) >> 10;
+                        /* vsz is in bytes and we want kb */
+                        sp->vsz = fast_strtoul_10(&cp) >> 10;
+                        /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
+                        sp->rss = fast_strtoul_10(&cp) << sp->shift_pages_to_kb;
 #endif
 
                         if (sp->vsz == 0 && sp->state[0] != 'Z')