From: Chuck Ebbert <76306.1226@compuserve.com> 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 --- arch/i386/kernel/cpu/amd.c | 8 ++++++++ arch/i386/kernel/cpu/centaur.c | 8 ++++++++ arch/i386/kernel/cpu/common.c | 11 ++++++++++- arch/i386/kernel/cpu/cyrix.c | 18 +++++++++++++++++- arch/i386/kernel/cpu/intel_cacheinfo.c | 1 + arch/i386/kernel/cpu/nexgen.c | 8 ++++++++ arch/i386/kernel/cpu/rise.c | 8 ++++++++ arch/i386/kernel/cpu/transmeta.c | 10 +++++++++- arch/i386/kernel/cpu/umc.c | 8 ++++++++ 9 files changed, 77 insertions(+), 3 deletions(-) diff -puN arch/i386/kernel/cpu/amd.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/amd.c --- 25/arch/i386/kernel/cpu/amd.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/amd.c Thu Feb 2 16:54:30 2006 @@ -282,3 +282,11 @@ int __init amd_init_cpu(void) } //early_arch_initcall(amd_init_cpu); + +int __init amd_exit_cpu(void) +{ + cpu_devs[X86_VENDOR_AMD] = NULL; + return 0; +} + +late_initcall(amd_exit_cpu); diff -puN arch/i386/kernel/cpu/centaur.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/centaur.c --- 25/arch/i386/kernel/cpu/centaur.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/centaur.c Thu Feb 2 16:54:30 2006 @@ -470,3 +470,11 @@ int __init centaur_init_cpu(void) } //early_arch_initcall(centaur_init_cpu); + +int __init centaur_exit_cpu(void) +{ + cpu_devs[X86_VENDOR_CENTAUR] = NULL; + return 0; +} + +late_initcall(centaur_exit_cpu); diff -puN arch/i386/kernel/cpu/common.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/common.c --- 25/arch/i386/kernel/cpu/common.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/common.c Thu Feb 2 16:54:30 2006 @@ -44,6 +44,7 @@ static void default_init(struct cpuinfo_ 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(str { 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(str 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; } diff -puN arch/i386/kernel/cpu/cyrix.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/cyrix.c --- 25/arch/i386/kernel/cpu/cyrix.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/cyrix.c Thu Feb 2 16:54:30 2006 @@ -345,7 +345,7 @@ static void __init init_cyrix(struct cpu /* * 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); +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); + +int __init nsc_exit_cpu(void) +{ + cpu_devs[X86_VENDOR_NSC] = NULL; + return 0; +} + +late_initcall(nsc_exit_cpu); diff -puN arch/i386/kernel/cpu/intel_cacheinfo.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/intel_cacheinfo.c --- 25/arch/i386/kernel/cpu/intel_cacheinfo.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/intel_cacheinfo.c Thu Feb 2 16:54:30 2006 @@ -152,6 +152,7 @@ static int __cpuinit cpuid4_cache_lookup 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; diff -puN arch/i386/kernel/cpu/nexgen.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/nexgen.c --- 25/arch/i386/kernel/cpu/nexgen.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/nexgen.c Thu Feb 2 16:54:30 2006 @@ -61,3 +61,11 @@ int __init nexgen_init_cpu(void) } //early_arch_initcall(nexgen_init_cpu); + +int __init nexgen_exit_cpu(void) +{ + cpu_devs[X86_VENDOR_NEXGEN] = NULL; + return 0; +} + +late_initcall(nexgen_exit_cpu); diff -puN arch/i386/kernel/cpu/rise.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/rise.c --- 25/arch/i386/kernel/cpu/rise.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/rise.c Thu Feb 2 16:54:30 2006 @@ -51,3 +51,11 @@ int __init rise_init_cpu(void) } //early_arch_initcall(rise_init_cpu); + +int __init rise_exit_cpu(void) +{ + cpu_devs[X86_VENDOR_RISE] = NULL; + return 0; +} + +late_initcall(rise_exit_cpu); diff -puN arch/i386/kernel/cpu/transmeta.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/transmeta.c --- 25/arch/i386/kernel/cpu/transmeta.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/transmeta.c Thu Feb 2 16:54:30 2006 @@ -84,7 +84,7 @@ static void __init init_transmeta(struct #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); + +int __init transmeta_exit_cpu(void) +{ + cpu_devs[X86_VENDOR_TRANSMETA] = NULL; + return 0; +} + +late_initcall(transmeta_exit_cpu); diff -puN arch/i386/kernel/cpu/umc.c~i386-cpu-hotplug-dont-access-freed-memory arch/i386/kernel/cpu/umc.c --- 25/arch/i386/kernel/cpu/umc.c~i386-cpu-hotplug-dont-access-freed-memory Thu Feb 2 16:54:30 2006 +++ 25-akpm/arch/i386/kernel/cpu/umc.c Thu Feb 2 16:54:30 2006 @@ -31,3 +31,11 @@ int __init umc_init_cpu(void) } //early_arch_initcall(umc_init_cpu); + +int __init umc_exit_cpu(void) +{ + cpu_devs[X86_VENDOR_UMC] = NULL; + return 0; +} + +late_initcall(umc_exit_cpu); _