diff --git a/libc/kernel/arch-x86/asm/pda.h b/libc/kernel/arch-x86/asm/pda.h
new file mode 100644
index 0000000..6711224
--- /dev/null
+++ b/libc/kernel/arch-x86/asm/pda.h
@@ -0,0 +1,65 @@
+/****************************************************************************
+ ****************************************************************************
+ ***
+ ***   This header was automatically generated from a Linux kernel header
+ ***   of the same name, to make information necessary for userspace to
+ ***   call into the kernel available to libc.  It contains only constants,
+ ***   structures, and macros generated from the original header, and thus,
+ ***   contains no copyrightable information.
+ ***
+ ****************************************************************************
+ ****************************************************************************/
+#ifndef X86_64_PDA_H
+#define X86_64_PDA_H
+
+#ifndef __ASSEMBLY__
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <asm/page.h>
+
+struct x8664_pda {
+ struct task_struct *pcurrent;
+ unsigned long data_offset;
+ unsigned long kernelstack;
+ unsigned long oldrsp;
+ int irqcount;
+ int cpunumber;
+ char *irqstackptr;
+ int nodenumber;
+ unsigned int __softirq_pending;
+ unsigned int __nmi_count;
+ short mmu_state;
+ short isidle;
+ struct mm_struct *active_mm;
+ unsigned apic_timer_irqs;
+ unsigned irq0_irqs;
+ unsigned irq_resched_count;
+ unsigned irq_call_count;
+ unsigned irq_tlb_count;
+ unsigned irq_thermal_count;
+ unsigned irq_threshold_count;
+ unsigned irq_spurious_count;
+} ____cacheline_aligned_in_smp;
+
+#define cpu_pda(i) (_cpu_pda[i])
+
+#define pda_offset(field) offsetof(struct x8664_pda, field)
+
+#define pda_to_op(op,field,val) do {   typedef typeof(_proxy_pda.field) T__;   if (0) { T__ tmp__; tmp__ = (val); }     switch (sizeof(_proxy_pda.field)) {   case 2:   asm(op "w %1,%%gs:%c2" :   "+m" (_proxy_pda.field) :   "ri" ((T__)val),   "i"(pda_offset(field)));   break;   case 4:   asm(op "l %1,%%gs:%c2" :   "+m" (_proxy_pda.field) :   "ri" ((T__)val),   "i" (pda_offset(field)));   break;   case 8:   asm(op "q %1,%%gs:%c2":   "+m" (_proxy_pda.field) :   "ri" ((T__)val),   "i"(pda_offset(field)));   break;   default:   __bad_pda_field();   }   } while (0)
+
+#define pda_from_op(op,field) ({   typeof(_proxy_pda.field) ret__;   switch (sizeof(_proxy_pda.field)) {   case 2:   asm(op "w %%gs:%c1,%0" :   "=r" (ret__) :   "i" (pda_offset(field)),   "m" (_proxy_pda.field));   break;   case 4:   asm(op "l %%gs:%c1,%0":   "=r" (ret__):   "i" (pda_offset(field)),   "m" (_proxy_pda.field));   break;   case 8:   asm(op "q %%gs:%c1,%0":   "=r" (ret__) :   "i" (pda_offset(field)),   "m" (_proxy_pda.field));   break;   default:   __bad_pda_field();   }   ret__; })
+
+#define read_pda(field) pda_from_op("mov",field)
+#define write_pda(field,val) pda_to_op("mov",field,val)
+#define add_pda(field,val) pda_to_op("add",field,val)
+#define sub_pda(field,val) pda_to_op("sub",field,val)
+#define or_pda(field,val) pda_to_op("or",field,val)
+
+#define test_and_clear_bit_pda(bit,field) ({   int old__;   asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0"   : "=r" (old__), "+m" (_proxy_pda.field)   : "dIr" (bit), "i" (pda_offset(field)) : "memory");   old__;  })
+
+#endif
+
+#define PDA_STACKOFFSET (5*8)
+
+#endif