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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ptrace.c (4491B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Ptrace support for Hexagon
      4 *
      5 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
      6 */
      7
      8#include <linux/kernel.h>
      9#include <linux/sched.h>
     10#include <linux/sched/task_stack.h>
     11#include <linux/mm.h>
     12#include <linux/smp.h>
     13#include <linux/errno.h>
     14#include <linux/ptrace.h>
     15#include <linux/regset.h>
     16#include <linux/user.h>
     17#include <linux/elf.h>
     18
     19#include <asm/user.h>
     20
     21#if arch_has_single_step()
     22/*  Both called from ptrace_resume  */
     23void user_enable_single_step(struct task_struct *child)
     24{
     25	pt_set_singlestep(task_pt_regs(child));
     26	set_tsk_thread_flag(child, TIF_SINGLESTEP);
     27}
     28
     29void user_disable_single_step(struct task_struct *child)
     30{
     31	pt_clr_singlestep(task_pt_regs(child));
     32	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
     33}
     34#endif
     35
     36static int genregs_get(struct task_struct *target,
     37		   const struct user_regset *regset,
     38		   struct membuf to)
     39{
     40	struct pt_regs *regs = task_pt_regs(target);
     41
     42	/* The general idea here is that the copyout must happen in
     43	 * exactly the same order in which the userspace expects these
     44	 * regs. Now, the sequence in userspace does not match the
     45	 * sequence in the kernel, so everything past the 32 gprs
     46	 * happens one at a time.
     47	 */
     48	membuf_write(&to, &regs->r00, 32*sizeof(unsigned long));
     49	/* Must be exactly same sequence as struct user_regs_struct */
     50	membuf_store(&to, regs->sa0);
     51	membuf_store(&to, regs->lc0);
     52	membuf_store(&to, regs->sa1);
     53	membuf_store(&to, regs->lc1);
     54	membuf_store(&to, regs->m0);
     55	membuf_store(&to, regs->m1);
     56	membuf_store(&to, regs->usr);
     57	membuf_store(&to, regs->preds);
     58	membuf_store(&to, regs->gp);
     59	membuf_store(&to, regs->ugp);
     60	membuf_store(&to, pt_elr(regs)); // pc
     61	membuf_store(&to, (unsigned long)pt_cause(regs)); // cause
     62	membuf_store(&to, pt_badva(regs)); // badva
     63#if CONFIG_HEXAGON_ARCH_VERSION >=4
     64	membuf_store(&to, regs->cs0);
     65	membuf_store(&to, regs->cs1);
     66	return membuf_zero(&to, sizeof(unsigned long));
     67#else
     68	return membuf_zero(&to, 3 * sizeof(unsigned long));
     69#endif
     70}
     71
     72static int genregs_set(struct task_struct *target,
     73		   const struct user_regset *regset,
     74		   unsigned int pos, unsigned int count,
     75		   const void *kbuf, const void __user *ubuf)
     76{
     77	int ret;
     78	unsigned long bucket;
     79	struct pt_regs *regs = task_pt_regs(target);
     80
     81	if (!regs)
     82		return -EIO;
     83
     84	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
     85				 &regs->r00, 0, 32*sizeof(unsigned long));
     86
     87#define INEXT(KPT_REG, USR_REG) \
     88	if (!ret) \
     89		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
     90			KPT_REG, offsetof(struct user_regs_struct, USR_REG), \
     91			offsetof(struct user_regs_struct, USR_REG) + \
     92				sizeof(unsigned long));
     93
     94	/* Must be exactly same sequence as struct user_regs_struct */
     95	INEXT(&regs->sa0, sa0);
     96	INEXT(&regs->lc0, lc0);
     97	INEXT(&regs->sa1, sa1);
     98	INEXT(&regs->lc1, lc1);
     99	INEXT(&regs->m0, m0);
    100	INEXT(&regs->m1, m1);
    101	INEXT(&regs->usr, usr);
    102	INEXT(&regs->preds, p3_0);
    103	INEXT(&regs->gp, gp);
    104	INEXT(&regs->ugp, ugp);
    105	INEXT(&pt_elr(regs), pc);
    106
    107	/* CAUSE and BADVA aren't writeable. */
    108	INEXT(&bucket, cause);
    109	INEXT(&bucket, badva);
    110
    111#if CONFIG_HEXAGON_ARCH_VERSION >=4
    112	INEXT(&regs->cs0, cs0);
    113	INEXT(&regs->cs1, cs1);
    114#endif
    115
    116	/* Ignore the rest, if needed */
    117	if (!ret)
    118		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
    119					offsetof(struct user_regs_struct, pad1), -1);
    120
    121	if (ret)
    122		return ret;
    123
    124	/*
    125	 * This is special; SP is actually restored by the VM via the
    126	 * special event record which is set by the special trap.
    127	 */
    128	regs->hvmer.vmpsp = regs->r29;
    129	return 0;
    130}
    131
    132enum hexagon_regset {
    133	REGSET_GENERAL,
    134};
    135
    136static const struct user_regset hexagon_regsets[] = {
    137	[REGSET_GENERAL] = {
    138		.core_note_type = NT_PRSTATUS,
    139		.n = ELF_NGREG,
    140		.size = sizeof(unsigned long),
    141		.align = sizeof(unsigned long),
    142		.regset_get = genregs_get,
    143		.set = genregs_set,
    144	},
    145};
    146
    147static const struct user_regset_view hexagon_user_view = {
    148	.name = "hexagon",
    149	.e_machine = ELF_ARCH,
    150	.ei_osabi = ELF_OSABI,
    151	.regsets = hexagon_regsets,
    152	.e_flags = ELF_CORE_EFLAGS,
    153	.n = ARRAY_SIZE(hexagon_regsets)
    154};
    155
    156const struct user_regset_view *task_user_regset_view(struct task_struct *task)
    157{
    158	return &hexagon_user_view;
    159}
    160
    161void ptrace_disable(struct task_struct *child)
    162{
    163	/* Boilerplate - resolves to null inline if no HW single-step */
    164	user_disable_single_step(child);
    165}
    166
    167long arch_ptrace(struct task_struct *child, long request,
    168		 unsigned long addr, unsigned long data)
    169{
    170	return ptrace_request(child, request, addr, data);
    171}