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Commit 82fab442 authored by Rusty Russell's avatar Rusty Russell
Browse files

modules: don't hand 0 to vmalloc. 

In commit d0a21265 David Rientjes unified various archs'
module_alloc implementation (including x86) and removed the graduitous
shortcut for size == 0.

Then, in commit de7d2b56, 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: default avatarConrad Kostecki <ConiKost@gmx.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 54523ec7

arch/cris/kernel/module.c

+0 −2
Original line number Diff line number Diff line
@@ -32,8 +32,6 @@ 
#ifdef CONFIG_ETRAX_KMALLOCED_MODULES

void *module_alloc(unsigned long size)

{

	if (size == 0)

		return NULL;

	return kmalloc(size, GFP_KERNEL);

}

arch/parisc/kernel/module.c

+0 −2
Original line number Diff line number Diff line
@@ -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 */

arch/sparc/kernel/module.c

+0 −4
Original line number Diff line number Diff line
@@ -43,10 +43,6 @@ void *module_alloc(unsigned long size) 
{

	void *ret;



	/* We handle the zero case fine, unlike vmalloc */

	if (size == 0)

		return NULL;



	ret = module_map(size);

	if (ret)

		memset(ret, 0, size);

arch/tile/kernel/module.c

+0 −2
Original line number Diff line number Diff line
@@ -42,8 +42,6 @@ void *module_alloc(unsigned long size) 
	int i = 0;

	int npages;



	if (size == 0)

		return NULL;

	npages = (size + PAGE_SIZE - 1) / PAGE_SIZE;

	pages = kmalloc(npages * sizeof(struct page *), GFP_KERNEL);

	if (pages == NULL)

arch/unicore32/kernel/module.c

+0 −3
Original line number Diff line number Diff line
@@ -27,9 +27,6 @@ void *module_alloc(unsigned long size) 
	struct vm_struct *area;



	size = PAGE_ALIGN(size);

	if (!size)

		return NULL;



	area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);

	if (!area)

		return NULL;