LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Jeff Dike <jdike@addtoit.com>
To: Andrew Morton <akpm@osdl.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
uml-devel <user-mode-linux-devel@lists.sourceforge.net>,
Miklos Szeredi <miklos@szeredi.hu>
Subject: [PATCH 5/5] UML - Fix mm_context memory leak
Date: Wed, 6 Feb 2008 12:44:48 -0500 [thread overview]
Message-ID: <20080206174448.GA7851@c2.user-mode-linux.org> (raw)
[ Spotted by Miklos ]
Fix a memory leak in init_new_context. The struct page ** buffer
allocated for install_special_mapping was never recorded, and thus
leaked when the mm_struct was freed. Fix it by saving the pointer in
mm_context_t and freeing it in arch_exit_mmap.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
---
arch/um/include/um_mmu.h | 1 +
arch/um/kernel/skas/mmu.c | 5 +++++
2 files changed, 6 insertions(+)
Index: linux-2.6-git/arch/um/include/um_mmu.h
===================================================================
--- linux-2.6-git.orig/arch/um/include/um_mmu.h 2008-02-06 12:15:05.000000000 -0500
+++ linux-2.6-git/arch/um/include/um_mmu.h 2008-02-06 12:24:08.000000000 -0500
@@ -13,6 +13,7 @@
typedef struct mm_context {
struct mm_id id;
struct uml_ldt ldt;
+ struct page **stub_pages;
} mm_context_t;
extern void __switch_mm(struct mm_id * mm_idp);
Index: linux-2.6-git/arch/um/kernel/skas/mmu.c
===================================================================
--- linux-2.6-git.orig/arch/um/kernel/skas/mmu.c 2008-02-06 12:15:05.000000000 -0500
+++ linux-2.6-git/arch/um/kernel/skas/mmu.c 2008-02-06 12:24:31.000000000 -0500
@@ -91,6 +91,8 @@ int init_new_context(struct task_struct
goto out_free;
}
+ to_mm->stub_pages = NULL;
+
return 0;
out_free:
@@ -126,6 +128,7 @@ void arch_dup_mmap(struct mm_struct *old
pages[0] = virt_to_page(&__syscall_stub_start);
pages[1] = virt_to_page(mm->context.id.stack);
+ mm->context.stub_pages = pages;
/* dup_mmap already holds mmap_sem */
err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
@@ -147,6 +150,8 @@ void arch_exit_mmap(struct mm_struct *mm
{
pte_t *pte;
+ if (mm->context.stub_pages != NULL)
+ kfree(mm->context.stub_pages);
pte = virt_to_pte(mm, STUB_CODE);
if (pte != NULL)
pte_clear(mm, STUB_CODE, pte);
reply other threads:[~2008-02-06 17:46 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20080206174448.GA7851@c2.user-mode-linux.org \
--to=jdike@addtoit.com \
--cc=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=user-mode-linux-devel@lists.sourceforge.net \
--subject='Re: [PATCH 5/5] UML - Fix mm_context memory leak' \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).