cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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kstack.h (2202B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _KSTACK_H
      3#define _KSTACK_H
      4
      5#include <linux/thread_info.h>
      6#include <linux/sched.h>
      7#include <asm/ptrace.h>
      8#include <asm/irq.h>
      9
     10/* SP must be STACK_BIAS adjusted already.  */
     11static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
     12{
     13	unsigned long base = (unsigned long) tp;
     14
     15	/* Stack pointer must be 16-byte aligned.  */
     16	if (sp & (16UL - 1))
     17		return false;
     18
     19	if (sp >= (base + sizeof(struct thread_info)) &&
     20	    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
     21		return true;
     22
     23	if (hardirq_stack[tp->cpu]) {
     24		base = (unsigned long) hardirq_stack[tp->cpu];
     25		if (sp >= base &&
     26		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
     27			return true;
     28		base = (unsigned long) softirq_stack[tp->cpu];
     29		if (sp >= base &&
     30		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
     31			return true;
     32	}
     33	return false;
     34}
     35
     36/* Does "regs" point to a valid pt_regs trap frame?  */
     37static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *regs)
     38{
     39	unsigned long base = (unsigned long) tp;
     40	unsigned long addr = (unsigned long) regs;
     41
     42	if (addr >= base &&
     43	    addr <= (base + THREAD_SIZE - sizeof(*regs)))
     44		goto check_magic;
     45
     46	if (hardirq_stack[tp->cpu]) {
     47		base = (unsigned long) hardirq_stack[tp->cpu];
     48		if (addr >= base &&
     49		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
     50			goto check_magic;
     51		base = (unsigned long) softirq_stack[tp->cpu];
     52		if (addr >= base &&
     53		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
     54			goto check_magic;
     55	}
     56	return false;
     57
     58check_magic:
     59	if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC)
     60		return true;
     61	return false;
     62
     63}
     64
     65static inline __attribute__((always_inline)) void *set_hardirq_stack(void)
     66{
     67	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
     68
     69	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
     70	if (orig_sp < sp ||
     71	    orig_sp > (sp + THREAD_SIZE)) {
     72		sp += THREAD_SIZE - 192 - STACK_BIAS;
     73		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
     74	}
     75
     76	return orig_sp;
     77}
     78
     79static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
     80{
     81	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
     82}
     83
     84#endif /* _KSTACK_H */