modules: don't hand 0 to vmalloc.

In commit d0a21265dfb5fa8a David Rientjes unified various archs'
module_alloc implementation (including x86) and removed the graduitous
shortcut for size == 0.

Then, in commit de7d2b567d040e3b, Joe Perches added a warning for
zero-length vmallocs, which can happen without kallsyms on modules
with no init sections (eg. zlib_deflate).

Fix this once and for all; the module code has to handle zero length
anyway, so get it right at the caller and remove the now-gratuitous
checks within the arch-specific module_alloc implementations.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42608
Reported-by: Conrad Kostecki <ConiKost@gmx.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 0 insertions, 2 deletions

diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index 5e34ccf39a49..2a625fb063e1 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -214,8 +214,6 @@ static inline int reassemble_22(int as22)
 
 void *module_alloc(unsigned long size)
 {
-        if (size == 0)
-                return NULL;
         /* using RWX means less protection for modules, but it's
          * easier than trying to map the text, data, init_text and
          * init_data correctly */