Commit fe38d855 authored by Chuck Ebbert's avatar Chuck Ebbert Committed by Linus Torvalds
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[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: default avatarChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 170aa3d0
......@@ -282,3 +282,11 @@ int __init amd_init_cpu(void)
}
//early_arch_initcall(amd_init_cpu);
static int __init amd_exit_cpu(void)
{
cpu_devs[X86_VENDOR_AMD] = NULL;
return 0;
}
late_initcall(amd_exit_cpu);
......@@ -470,3 +470,11 @@ int __init centaur_init_cpu(void)
}
//early_arch_initcall(centaur_init_cpu);
static int __init centaur_exit_cpu(void)
{
cpu_devs[X86_VENDOR_CENTAUR] = NULL;
return 0;
}
late_initcall(centaur_exit_cpu);
......@@ -44,6 +44,7 @@ static void default_init(struct cpuinfo_x86 * c)
static struct cpu_dev default_cpu = {
.c_init = default_init,
.c_vendor = "Unknown",
};
static struct cpu_dev * this_cpu = &default_cpu;
......@@ -150,6 +151,7 @@ static void __devinit get_cpu_vendor(struct cpuinfo_x86 *c, int early)
{
char *v = c->x86_vendor_id;
int i;
static int printed;
for (i = 0; i < X86_VENDOR_NUM; i++) {
if (cpu_devs[i]) {
......@@ -159,10 +161,17 @@ static void __devinit get_cpu_vendor(struct cpuinfo_x86 *c, int early)
c->x86_vendor = i;
if (!early)
this_cpu = cpu_devs[i];
break;
return;
}
}
}
if (!printed) {
printed++;
printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
printk(KERN_ERR "CPU: Your system may be unstable.\n");
}
c->x86_vendor = X86_VENDOR_UNKNOWN;
this_cpu = &default_cpu;
}
......
......@@ -345,7 +345,7 @@ static void __init init_cyrix(struct cpuinfo_x86 *c)
/*
* 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 @@ int __init cyrix_init_cpu(void)
//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 @@ int __init nsc_init_cpu(void)
}
//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);
......@@ -152,6 +152,7 @@ static int __cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_le
return 0;
}
/* will only be called once; __init is safe here */
static int __init find_num_cache_leaves(void)
{
unsigned int eax, ebx, ecx, edx;
......
......@@ -61,3 +61,11 @@ int __init nexgen_init_cpu(void)
}
//early_arch_initcall(nexgen_init_cpu);
static int __init nexgen_exit_cpu(void)
{
cpu_devs[X86_VENDOR_NEXGEN] = NULL;
return 0;
}
late_initcall(nexgen_exit_cpu);
......@@ -51,3 +51,11 @@ int __init rise_init_cpu(void)
}
//early_arch_initcall(rise_init_cpu);
static int __init rise_exit_cpu(void)
{
cpu_devs[X86_VENDOR_RISE] = NULL;
return 0;
}
late_initcall(rise_exit_cpu);
......@@ -84,7 +84,7 @@ static void __init init_transmeta(struct cpuinfo_x86 *c)
#endif
}
static void transmeta_identify(struct cpuinfo_x86 * c)
static void __init transmeta_identify(struct cpuinfo_x86 * c)
{
u32 xlvl;
generic_identify(c);
......@@ -111,3 +111,11 @@ int __init transmeta_init_cpu(void)
}
//early_arch_initcall(transmeta_init_cpu);
static int __init transmeta_exit_cpu(void)
{
cpu_devs[X86_VENDOR_TRANSMETA] = NULL;
return 0;
}
late_initcall(transmeta_exit_cpu);
......@@ -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);
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