From: "Thomas Weißschuh" <linux@weissschuh.net>
To: Richard Weinberger <richard@nod.at>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Johannes Berg <johannes@sipsolutions.net>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org,
"Thomas Weißschuh" <linux@weissschuh.net>
Subject: [PATCH 3/4] x86/um/vdso: Panic when vDSO can not be allocated
Date: Mon, 13 Oct 2025 12:40:20 +0200 [thread overview]
Message-ID: <20251013-uml-vdso-cleanup-v1-3-a079c7adcc69@weissschuh.net> (raw)
In-Reply-To: <20251013-uml-vdso-cleanup-v1-0-a079c7adcc69@weissschuh.net>
The vDSO address is added to the userspace auxiliary vectors even if the
vDSO was not allocated. When accessing the page, userspace processes
will crash.
Enforce that the allocation works.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
arch/x86/um/vdso/vma.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
index dc8dfb2abd80..51a2b9f2eca9 100644
--- a/arch/x86/um/vdso/vma.c
+++ b/arch/x86/um/vdso/vma.c
@@ -10,7 +10,6 @@
#include <asm/elf.h>
#include <linux/init.h>
-static unsigned int __read_mostly vdso_enabled = 1;
unsigned long um_vdso_addr;
static struct page *um_vdso;
@@ -25,17 +24,11 @@ static int __init init_vdso(void)
um_vdso = alloc_page(GFP_KERNEL);
if (!um_vdso)
- goto oom;
+ panic("Cannot allocate vdso\n");
copy_page(page_address(um_vdso), vdso_start);
return 0;
-
-oom:
- printk(KERN_ERR "Cannot allocate vdso\n");
- vdso_enabled = 0;
-
- return -ENOMEM;
}
subsys_initcall(init_vdso);
@@ -48,9 +41,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
.pages = &um_vdso,
};
- if (!vdso_enabled)
- return 0;
-
if (mmap_write_lock_killable(mm))
return -EINTR;
--
2.51.0
next prev parent reply other threads:[~2025-10-13 10:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-13 10:40 [PATCH 0/4] x86/um/vdso: Cleanups Thomas Weißschuh
2025-10-13 10:40 ` [PATCH 1/4] x86/um/vdso: Fix prototype of clock_gettime() Thomas Weißschuh
2025-10-13 10:40 ` [PATCH 2/4] x86/um/vdso: Use prototypes from generic vDSO headers Thomas Weißschuh
2025-10-13 10:40 ` Thomas Weißschuh [this message]
2025-10-13 10:40 ` [PATCH 4/4] x86/um/vdso: Drop VDSO64-y from Makefile Thomas Weißschuh
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