[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>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/i386/kernel/cpu/umc.c b/arch/i386/kernel/cpu/umc.c
index 264fcad559d5..2cd988f6dc55 100644
--- a/arch/i386/kernel/cpu/umc.c
+++ b/arch/i386/kernel/cpu/umc.c
@@ -31,3 +31,11 @@ int __init umc_init_cpu(void)
 }
 
 //early_arch_initcall(umc_init_cpu);
+
+static int __init umc_exit_cpu(void)
+{
+	cpu_devs[X86_VENDOR_UMC] = NULL;
+	return 0;
+}
+
+late_initcall(umc_exit_cpu);