With the MEM_FIND_ZONE operation, and the expectation that it will be
called from 'daxctl list' listings, it is possible that memblock_in_dev()
gets called without sufficient privileges. If this happens, currently,
the above simply returns a 'false'. This was acceptable when the only
operations were onlining/offlining (as there would be an actual failure
later). However, it is not acceptable in the MEM_FIND_ZONE case, as it
could yeild a different answer based on the privilege level.

Change memblock_in_dev() to return an 'int' instead of a 'bool' so that
error cases can be distinguished from actual address range test.

Cc: Dan Williams <[email protected]>
Signed-off-by: Vishal Verma <[email protected]>
---
 daxctl/lib/libdaxctl.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/daxctl/lib/libdaxctl.c b/daxctl/lib/libdaxctl.c
index 4460174..617887c 100644
--- a/daxctl/lib/libdaxctl.c
+++ b/daxctl/lib/libdaxctl.c
@@ -1211,40 +1211,42 @@ static int memblock_find_zone(struct daxctl_memory 
*mem, char *memblock,
        return 0;
 }
 
-static bool memblock_in_dev(struct daxctl_memory *mem, const char *memblock)
+static int memblock_in_dev(struct daxctl_memory *mem, const char *memblock)
 {
        const char *mem_base = "/sys/devices/system/memory/";
        struct daxctl_dev *dev = daxctl_memory_get_dev(mem);
        unsigned long long memblock_res, dev_start, dev_end;
        const char *devname = daxctl_dev_get_devname(dev);
        struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+       int rc, path_len = mem->buf_len;
        unsigned long memblock_size;
-       int path_len = mem->buf_len;
        char buf[SYSFS_ATTR_SIZE];
        unsigned long phys_index;
        char *path = mem->mem_buf;
 
        if (snprintf(path, path_len, "%s/%s/phys_index",
                        mem_base, memblock) < 0)
-               return false;
+               return -ENXIO;
 
-       if (sysfs_read_attr(ctx, path, buf) == 0) {
+       rc = sysfs_read_attr(ctx, path, buf);
+       if (rc == 0) {
                phys_index = strtoul(buf, NULL, 16);
                if (phys_index == 0 || phys_index == ULONG_MAX) {
+                       rc = -errno;
                        err(ctx, "%s: %s: Unable to determine phys_index: %s\n",
-                               devname, memblock, strerror(errno));
-                       return false;
+                               devname, memblock, strerror(-rc));
+                       return rc;
                }
        } else {
                err(ctx, "%s: %s: Unable to determine phys_index: %s\n",
-                       devname, memblock, strerror(errno));
-               return false;
+                       devname, memblock, strerror(-rc));
+               return rc;
        }
 
        dev_start = daxctl_dev_get_resource(dev);
        if (!dev_start) {
                err(ctx, "%s: Unable to determine resource\n", devname);
-               return false;
+               return -EACCES;
        }
        dev_end = dev_start + daxctl_dev_get_size(dev);
 
@@ -1252,14 +1254,14 @@ static bool memblock_in_dev(struct daxctl_memory *mem, 
const char *memblock)
        if (!memblock_size) {
                err(ctx, "%s: Unable to determine memory block size\n",
                        devname);
-               return false;
+               return -ENXIO;
        }
        memblock_res = phys_index * memblock_size;
 
        if (memblock_res >= dev_start && memblock_res <= dev_end)
-               return true;
+               return 1;
 
-       return false;
+       return 0;
 }
 
 static int op_for_one_memblock(struct daxctl_memory *mem, char *memblock,
@@ -1317,8 +1319,12 @@ static int daxctl_memory_op(struct daxctl_memory *mem, 
enum memory_op op)
        errno = 0;
        while ((de = readdir(node_dir)) != NULL) {
                if (strncmp(de->d_name, "memory", 6) == 0) {
-                       if (!memblock_in_dev(mem, de->d_name))
+                       rc = memblock_in_dev(mem, de->d_name);
+                       if (rc < 0)
+                               goto out_dir;
+                       if (rc == 0) /* memblock not in dev */
                                continue;
+                       /* memblock is in dev, perform op */
                        rc = op_for_one_memblock(mem, de->d_name, op,
                                        &status_flags);
                        if (rc < 0)
-- 
2.20.1
_______________________________________________
Linux-nvdimm mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to