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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perf_regs.c (1556B)


      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/perf_event.h>
      3#include <linux/perf_regs.h>
      4#include <linux/kernel.h>
      5#include <linux/errno.h>
      6#include <linux/bug.h>
      7#include <asm/ptrace.h>
      8#include <asm/fpu/api.h>
      9#include <asm/fpu/types.h>
     10
     11u64 perf_reg_value(struct pt_regs *regs, int idx)
     12{
     13	freg_t fp;
     14
     15	if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15)
     16		return regs->gprs[idx];
     17
     18	if (idx >= PERF_REG_S390_FP0 && idx <= PERF_REG_S390_FP15) {
     19		if (!user_mode(regs))
     20			return 0;
     21
     22		idx -= PERF_REG_S390_FP0;
     23		fp = MACHINE_HAS_VX ? *(freg_t *)(current->thread.fpu.vxrs + idx)
     24				    : current->thread.fpu.fprs[idx];
     25		return fp.ui;
     26	}
     27
     28	if (idx == PERF_REG_S390_MASK)
     29		return regs->psw.mask;
     30	if (idx == PERF_REG_S390_PC)
     31		return regs->psw.addr;
     32
     33	WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX);
     34	return 0;
     35}
     36
     37#define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1))
     38
     39int perf_reg_validate(u64 mask)
     40{
     41	if (!mask || mask & REG_RESERVED)
     42		return -EINVAL;
     43
     44	return 0;
     45}
     46
     47u64 perf_reg_abi(struct task_struct *task)
     48{
     49	if (test_tsk_thread_flag(task, TIF_31BIT))
     50		return PERF_SAMPLE_REGS_ABI_32;
     51
     52	return PERF_SAMPLE_REGS_ABI_64;
     53}
     54
     55void perf_get_regs_user(struct perf_regs *regs_user,
     56			struct pt_regs *regs)
     57{
     58	/*
     59	 * Use the regs from the first interruption and let
     60	 * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).
     61	 *
     62	 * Also save FPU registers for user-space tasks only.
     63	 */
     64	regs_user->regs = task_pt_regs(current);
     65	if (user_mode(regs_user->regs))
     66		save_fpu_regs();
     67	regs_user->abi = perf_reg_abi(current);
     68}