mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 06:16:46 +07:00
fe38d8553c
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>
72 lines
1.4 KiB
C
72 lines
1.4 KiB
C
#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <asm/processor.h>
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#include "cpu.h"
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/*
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* Detect a NexGen CPU running without BIOS hypercode new enough
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* to have CPUID. (Thanks to Herbert Oppmann)
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*/
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static int __init deep_magic_nexgen_probe(void)
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{
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int ret;
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__asm__ __volatile__ (
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" movw $0x5555, %%ax\n"
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" xorw %%dx,%%dx\n"
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" movw $2, %%cx\n"
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" divw %%cx\n"
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" movl $0, %%eax\n"
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" jnz 1f\n"
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" movl $1, %%eax\n"
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"1:\n"
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: "=a" (ret) : : "cx", "dx" );
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return ret;
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}
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static void __init init_nexgen(struct cpuinfo_x86 * c)
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{
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c->x86_cache_size = 256; /* A few had 1 MB... */
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}
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static void __init nexgen_identify(struct cpuinfo_x86 * c)
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{
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/* Detect NexGen with old hypercode */
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if ( deep_magic_nexgen_probe() ) {
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strcpy(c->x86_vendor_id, "NexGenDriven");
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}
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generic_identify(c);
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}
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static struct cpu_dev nexgen_cpu_dev __initdata = {
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.c_vendor = "Nexgen",
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.c_ident = { "NexGenDriven" },
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.c_models = {
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{ .vendor = X86_VENDOR_NEXGEN,
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.family = 5,
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.model_names = { [1] = "Nx586" }
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},
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},
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.c_init = init_nexgen,
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.c_identify = nexgen_identify,
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};
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int __init nexgen_init_cpu(void)
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{
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cpu_devs[X86_VENDOR_NEXGEN] = &nexgen_cpu_dev;
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return 0;
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}
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//early_arch_initcall(nexgen_init_cpu);
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static int __init nexgen_exit_cpu(void)
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{
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cpu_devs[X86_VENDOR_NEXGEN] = NULL;
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return 0;
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}
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late_initcall(nexgen_exit_cpu);
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