Commit bd9e0b74 authored by Shaohua Li's avatar Shaohua Li Committed by Linus Torvalds

[PATCH] x86: cpu_init(): avoid GFP_KERNEL allocation while atomic

The patch fixes two issues:

1.  cpu_init is called with interrupt disabled.  Allocating gdt table
   there isn't good at runtime.

2. gdt table page cause memory leak in CPU hotplug case.
Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 28eba5bf
...@@ -613,6 +613,12 @@ void __cpuinit cpu_init(void) ...@@ -613,6 +613,12 @@ void __cpuinit cpu_init(void)
set_in_cr4(X86_CR4_TSD); set_in_cr4(X86_CR4_TSD);
} }
/* The CPU hotplug case */
if (cpu_gdt_descr->address) {
gdt = (struct desc_struct *)cpu_gdt_descr->address;
memset(gdt, 0, PAGE_SIZE);
goto old_gdt;
}
/* /*
* This is a horrible hack to allocate the GDT. The problem * This is a horrible hack to allocate the GDT. The problem
* is that cpu_init() is called really early for the boot CPU * is that cpu_init() is called really early for the boot CPU
...@@ -631,7 +637,7 @@ void __cpuinit cpu_init(void) ...@@ -631,7 +637,7 @@ void __cpuinit cpu_init(void)
local_irq_enable(); local_irq_enable();
} }
} }
old_gdt:
/* /*
* Initialize the per-CPU GDT with the boot GDT, * Initialize the per-CPU GDT with the boot GDT,
* and set up the GDT descriptor: * and set up the GDT descriptor:
......
...@@ -1056,6 +1056,7 @@ static int __cpuinit __smp_prepare_cpu(int cpu) ...@@ -1056,6 +1056,7 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
struct warm_boot_cpu_info info; struct warm_boot_cpu_info info;
struct work_struct task; struct work_struct task;
int apicid, ret; int apicid, ret;
struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
apicid = x86_cpu_to_apicid[cpu]; apicid = x86_cpu_to_apicid[cpu];
if (apicid == BAD_APICID) { if (apicid == BAD_APICID) {
...@@ -1063,6 +1064,18 @@ static int __cpuinit __smp_prepare_cpu(int cpu) ...@@ -1063,6 +1064,18 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
goto exit; goto exit;
} }
/*
* the CPU isn't initialized at boot time, allocate gdt table here.
* cpu_init will initialize it
*/
if (!cpu_gdt_descr->address) {
cpu_gdt_descr->address = get_zeroed_page(GFP_KERNEL);
if (!cpu_gdt_descr->address)
printk(KERN_CRIT "CPU%d failed to allocate GDT\n", cpu);
ret = -ENOMEM;
goto exit;
}
info.complete = &done; info.complete = &done;
info.apicid = apicid; info.apicid = apicid;
info.cpu = cpu; info.cpu = cpu;
......
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