palinfo fixes

	* check for proc_mkdir() failures
	* fix buffer overrun - sizeof(format string) is *not* enough to
hold sprintf() result.
	* use proc_remove_subtree(); life's much easier with it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c
index 77597e5ea60aca9429f29c26ec7973bf89a19683..79521d5499f94e906c7a0fece9cfe206d7629c79 100644 (file)
--- a/arch/ia64/kernel/palinfo.c
+++ b/arch/ia64/kernel/palinfo.c
@@ -849,17 +849,6 @@ static palinfo_entry_t palinfo_entries[]={
 
 #define NR_PALINFO_ENTRIES     (int) ARRAY_SIZE(palinfo_entries)
 
-/*
- * this array is used to keep track of the proc entries we create. This is
- * required in the module mode when we need to remove all entries. The procfs code
- * does not do recursion of deletion
- *
- * Notes:
- *     - +1 accounts for the cpuN directory entry in /proc/pal
- */
-#define NR_PALINFO_PROC_ENTRIES        (NR_CPUS*(NR_PALINFO_ENTRIES+1))
-
-static struct proc_dir_entry *palinfo_proc_entries[NR_PALINFO_PROC_ENTRIES];
 static struct proc_dir_entry *palinfo_dir;
 
 /*
@@ -971,60 +960,32 @@ palinfo_read_entry(char *page, char **start, off_t off, int count, int *eof, voi
 static void __cpuinit
 create_palinfo_proc_entries(unsigned int cpu)
 {
-#      define CPUSTR   "cpu%d"
-
        pal_func_cpu_u_t f;
-       struct proc_dir_entry **pdir;
        struct proc_dir_entry *cpu_dir;
        int j;
-       char cpustr[sizeof(CPUSTR)];
-
-
-       /*
-        * we keep track of created entries in a depth-first order for
-        * cleanup purposes. Each entry is stored into palinfo_proc_entries
-        */
-       sprintf(cpustr,CPUSTR, cpu);
+       char cpustr[3+4+1];     /* cpu numbers are up to 4095 on itanic */
+       sprintf(cpustr, "cpu%d", cpu);
 
        cpu_dir = proc_mkdir(cpustr, palinfo_dir);
+       if (!cpu_dir)
+               return;
 
        f.req_cpu = cpu;
 
-       /*
-        * Compute the location to store per cpu entries
-        * We dont store the top level entry in this list, but
-        * remove it finally after removing all cpu entries.
-        */
-       pdir = &palinfo_proc_entries[cpu*(NR_PALINFO_ENTRIES+1)];
-       *pdir++ = cpu_dir;
        for (j=0; j < NR_PALINFO_ENTRIES; j++) {
                f.func_id = j;
-               *pdir = create_proc_read_entry(
-                               palinfo_entries[j].name, 0, cpu_dir,
-                               palinfo_read_entry, (void *)f.value);
-               pdir++;
+               create_proc_read_entry(
+                       palinfo_entries[j].name, 0, cpu_dir,
+                       palinfo_read_entry, (void *)f.value);
        }
 }
 
 static void
 remove_palinfo_proc_entries(unsigned int hcpu)
 {
-       int j;
-       struct proc_dir_entry *cpu_dir, **pdir;
-
-       pdir = &palinfo_proc_entries[hcpu*(NR_PALINFO_ENTRIES+1)];
-       cpu_dir = *pdir;
-       *pdir++=NULL;
-       for (j=0; j < (NR_PALINFO_ENTRIES); j++) {
-               if ((*pdir)) {
-                       remove_proc_entry ((*pdir)->name, cpu_dir);
-                       *pdir ++= NULL;
-               }
-       }
-
-       if (cpu_dir) {
-               remove_proc_entry(cpu_dir->name, palinfo_dir);
-       }
+       char cpustr[3+4+1];     /* cpu numbers are up to 4095 on itanic */
+       sprintf(cpustr, "cpu%d", hcpu);
+       remove_proc_subtree(cpustr, palinfo_dir);
 }
 
 static int __cpuinit palinfo_cpu_callback(struct notifier_block *nfb,
@@ -1058,6 +1019,8 @@ palinfo_init(void)
 
        printk(KERN_INFO "PAL Information Facility v%s\n", PALINFO_VERSION);
        palinfo_dir = proc_mkdir("pal", NULL);
+       if (!palinfo_dir)
+               return -ENOMEM;
 
        /* Create palinfo dirs in /proc for all online cpus */
        for_each_online_cpu(i) {
@@ -1073,22 +1036,8 @@ palinfo_init(void)
 static void __exit
 palinfo_exit(void)
 {
-       int i = 0;
-
-       /* remove all nodes: depth first pass. Could optimize this  */
-       for_each_online_cpu(i) {
-               remove_palinfo_proc_entries(i);
-       }
-
-       /*
-        * Remove the top level entry finally
-        */
-       remove_proc_entry(palinfo_dir->name, NULL);
-
-       /*
-        * Unregister from cpu notifier callbacks
-        */
        unregister_hotcpu_notifier(&palinfo_cpu_notifier);
+       remove_proc_subtree("pal", NULL);
 }
 
 module_init(palinfo_init);