[dpdk-dev] [PATCH] usertools: check 0-division with hugepage size

The default page size can be None, and the page size from user request
can be 0 kB if lower than 1024. In these cases, a division will fail.
In order to avoid a Python exception, the page size is checked
and an error message "Invalid page size" is printed.

A similar error message is printed in set_hugepages()
if the size is not supported, except at this stage the message can be
completed with "Valid page sizes".
Unfortunately the first check is too early to print such information.

A third error message can be printed in a different place (get_memsize)
in case of a format issue, e.g. a negative size.
The function get_memsize() is also used for total requested size,
so the error message "not a valid page size" was potentially wrong.
This message is replaced with the more general "is not a valid size".

Signed-off-by: Thomas Monjalon <redacted>
---
 usertools/dpdk-hugepages.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/usertools/dpdk-hugepages.py b/usertools/dpdk-hugepages.py
index fb368b6933..c1f2549ec0 100755
--- a/usertools/dpdk-hugepages.py
+++ b/usertools/dpdk-hugepages.py

@@ -29,7 +29,7 @@ def get_memsize(arg):
     '''Convert memory size with suffix to kB'''
     match = re.match(r'(\d+)([' + BINARY_PREFIX + r']?)$', arg.upper())
     if match is None:
-        sys.exit('{} is not a valid page size'.format(arg))
+        sys.exit('{} is not a valid size'.format(arg))
     num = float(match.group(1))
     suffix = match.group(2)
     if suffix == "":

@@ -254,6 +254,8 @@ def main():
         pagesize_kb = get_memsize(args.pagesize)
     else:
         pagesize_kb = default_pagesize()
+    if pagesize_kb is None or pagesize_kb == 0:
+        sys.exit("Invalid page size: {}kB".format(pagesize_kb))
 
     if args.clear:
         clear_pages()

-- 
2.30.0

On Thu, 11 Feb 2021 23:05:44 +0100
Thomas Monjalon [off-list ref] wrote:

The default page size can be None, and the page size from user request
can be 0 kB if lower than 1024. In these cases, a division will fail.
In order to avoid a Python exception, the page size is checked
and an error message "Invalid page size" is printed.

A similar error message is printed in set_hugepages()
if the size is not supported, except at this stage the message can be
completed with "Valid page sizes".
Unfortunately the first check is too early to print such information.

A third error message can be printed in a different place (get_memsize)
in case of a format issue, e.g. a negative size.
The function get_memsize() is also used for total requested size,
so the error message "not a valid page size" was potentially wrong.
This message is replaced with the more general "is not a valid size".

Signed-off-by: Thomas Monjalon <redacted>

Acked-by: Stephen Hemminger <stephen@networkplumber.org>

On 11-Feb-21 10:05 PM, Thomas Monjalon wrote:

Both None and 0 evaluate to False for boolean comparisons, so you can 
replace it with:

if not pagesize_kb:
    sys.exit(...)

  
      if args.clear:
          clear_pages()

-- 
Thanks,
Anatoly

12/02/2021 12:27, Burakov, Anatoly:

On 11-Feb-21 10:05 PM, Thomas Monjalon wrote:

quoted

The default page size can be None, and the page size from user request
can be 0 kB if lower than 1024. In these cases, a division will fail.
In order to avoid a Python exception, the page size is checked
and an error message "Invalid page size" is printed.

A similar error message is printed in set_hugepages()
if the size is not supported, except at this stage the message can be
completed with "Valid page sizes".
Unfortunately the first check is too early to print such information.

A third error message can be printed in a different place (get_memsize)
in case of a format issue, e.g. a negative size.
The function get_memsize() is also used for total requested size,
so the error message "not a valid page size" was potentially wrong.
This message is replaced with the more general "is not a valid size".

Signed-off-by: Thomas Monjalon <redacted>
---

@@ -254,6 +254,8 @@ def main():
          pagesize_kb = get_memsize(args.pagesize)
      else:
          pagesize_kb = default_pagesize()
+    if pagesize_kb is None or pagesize_kb == 0:
+        sys.exit("Invalid page size: {}kB".format(pagesize_kb))

Both None and 0 evaluate to False for boolean comparisons, so you can 
replace it with:

if not pagesize_kb:
    sys.exit(...)

Oh yes better :)

The default page size can be None, and the page size from user request
can be 0 kB if lower than 1024. In these cases, a division will fail.
In order to avoid a Python exception, the page size is checked
and an error message "Invalid page size" is printed.

A similar error message is printed in set_hugepages()
if the size is not supported, except at this stage the message can be
completed with "Valid page sizes".
Unfortunately the first check is too early to print such information.

A third error message can be printed in a different place (get_memsize)
in case of a format issue, e.g. a negative size.
The function get_memsize() is also used for total requested size,
so the error message "not a valid page size" was potentially wrong.
This message is replaced with the more general "is not a valid size".

Signed-off-by: Thomas Monjalon <redacted>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
---
v2: use simple "if not" construct for both None and 0
---
 usertools/dpdk-hugepages.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/usertools/dpdk-hugepages.py b/usertools/dpdk-hugepages.py
index fb368b6933..db141b3efa 100755
--- a/usertools/dpdk-hugepages.py
+++ b/usertools/dpdk-hugepages.py

@@ -29,7 +29,7 @@ def get_memsize(arg):
     '''Convert memory size with suffix to kB'''
     match = re.match(r'(\d+)([' + BINARY_PREFIX + r']?)$', arg.upper())
     if match is None:
-        sys.exit('{} is not a valid page size'.format(arg))
+        sys.exit('{} is not a valid size'.format(arg))
     num = float(match.group(1))
     suffix = match.group(2)
     if suffix == "":

@@ -254,6 +254,8 @@ def main():
         pagesize_kb = get_memsize(args.pagesize)
     else:
         pagesize_kb = default_pagesize()
+    if not pagesize_kb:
+        sys.exit("Invalid page size: {}kB".format(pagesize_kb))
 
     if args.clear:
         clear_pages()

-- 
2.30.1

On 21-Mar-21 9:09 AM, Thomas Monjalon wrote:

The default page size can be None, and the page size from user request
can be 0 kB if lower than 1024. In these cases, a division will fail.
In order to avoid a Python exception, the page size is checked
and an error message "Invalid page size" is printed.

A similar error message is printed in set_hugepages()
if the size is not supported, except at this stage the message can be
completed with "Valid page sizes".
Unfortunately the first check is too early to print such information.

A third error message can be printed in a different place (get_memsize)
in case of a format issue, e.g. a negative size.
The function get_memsize() is also used for total requested size,
so the error message "not a valid page size" was potentially wrong.
This message is replaced with the more general "is not a valid size".

Signed-off-by: Thomas Monjalon <redacted>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
---
v2: use simple "if not" construct for both None and 0
---

Acked-by: Anatoly Burakov <redacted>

-- 
Thanks,
Anatoly

23/03/2021 12:30, Burakov, Anatoly:

On 21-Mar-21 9:09 AM, Thomas Monjalon wrote:

quoted

The default page size can be None, and the page size from user request
can be 0 kB if lower than 1024. In these cases, a division will fail.
In order to avoid a Python exception, the page size is checked
and an error message "Invalid page size" is printed.

A similar error message is printed in set_hugepages()
if the size is not supported, except at this stage the message can be
completed with "Valid page sizes".
Unfortunately the first check is too early to print such information.

A third error message can be printed in a different place (get_memsize)
in case of a format issue, e.g. a negative size.
The function get_memsize() is also used for total requested size,
so the error message "not a valid page size" was potentially wrong.
This message is replaced with the more general "is not a valid size".

Signed-off-by: Thomas Monjalon <redacted>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
---
v2: use simple "if not" construct for both None and 0
---

Acked-by: Anatoly Burakov <redacted>

Applied