[PATCH] i386 cpu hotplug: don't access freed memory
i386 CPU init code accesses freed init memory when booting a newly-started
processor after CPU hotplug. The cpu_devs array is searched to find the
vendor and it contains pointers to freed data.
Fix that by:
1. Zeroing entries for freed vendor data after bootup.
2. Changing Transmeta, NSC and UMC to all __init[data].
3. Printing a warning (once only) and setting this_cpu
to a safe default when the vendor is not found.
This does not change behavior for AMD systems. They were broken already
but no error was reported.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/cpu/cyrix.c b/arch/i386/kernel/cpu/cyrix.c
index 7501597..00f2e05 100644
--- a/arch/i386/kernel/cpu/cyrix.c
+++ b/arch/i386/kernel/cpu/cyrix.c
@@ -345,7 +345,7 @@
/*
* Handle National Semiconductor branded processors
*/
-static void __devinit init_nsc(struct cpuinfo_x86 *c)
+static void __init init_nsc(struct cpuinfo_x86 *c)
{
/* There may be GX1 processors in the wild that are branded
* NSC and not Cyrix.
@@ -444,6 +444,14 @@
//early_arch_initcall(cyrix_init_cpu);
+static int __init cyrix_exit_cpu(void)
+{
+ cpu_devs[X86_VENDOR_CYRIX] = NULL;
+ return 0;
+}
+
+late_initcall(cyrix_exit_cpu);
+
static struct cpu_dev nsc_cpu_dev __initdata = {
.c_vendor = "NSC",
.c_ident = { "Geode by NSC" },
@@ -458,3 +466,11 @@
}
//early_arch_initcall(nsc_init_cpu);
+
+static int __init nsc_exit_cpu(void)
+{
+ cpu_devs[X86_VENDOR_NSC] = NULL;
+ return 0;
+}
+
+late_initcall(nsc_exit_cpu);