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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process_32.c (10534B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*  linux/arch/sparc/kernel/process.c
      3 *
      4 *  Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
      5 *  Copyright (C) 1996 Eddie C. Dost   (ecd@skynet.be)
      6 */
      7
      8/*
      9 * This file handles the architecture-dependent parts of process handling..
     10 */
     11#include <linux/elfcore.h>
     12#include <linux/errno.h>
     13#include <linux/module.h>
     14#include <linux/sched.h>
     15#include <linux/sched/debug.h>
     16#include <linux/sched/task.h>
     17#include <linux/sched/task_stack.h>
     18#include <linux/kernel.h>
     19#include <linux/mm.h>
     20#include <linux/stddef.h>
     21#include <linux/ptrace.h>
     22#include <linux/user.h>
     23#include <linux/smp.h>
     24#include <linux/reboot.h>
     25#include <linux/delay.h>
     26#include <linux/pm.h>
     27#include <linux/slab.h>
     28#include <linux/cpu.h>
     29
     30#include <asm/auxio.h>
     31#include <asm/oplib.h>
     32#include <linux/uaccess.h>
     33#include <asm/page.h>
     34#include <asm/delay.h>
     35#include <asm/processor.h>
     36#include <asm/psr.h>
     37#include <asm/elf.h>
     38#include <asm/prom.h>
     39#include <asm/unistd.h>
     40#include <asm/setup.h>
     41
     42#include "kernel.h"
     43
     44/* 
     45 * Power management idle function 
     46 * Set in pm platform drivers (apc.c and pmc.c)
     47 */
     48void (*sparc_idle)(void);
     49
     50/* 
     51 * Power-off handler instantiation for pm.h compliance
     52 * This is done via auxio, but could be used as a fallback
     53 * handler when auxio is not present-- unused for now...
     54 */
     55void (*pm_power_off)(void) = machine_power_off;
     56EXPORT_SYMBOL(pm_power_off);
     57
     58/*
     59 * sysctl - toggle power-off restriction for serial console 
     60 * systems in machine_power_off()
     61 */
     62int scons_pwroff = 1;
     63
     64extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
     65
     66struct task_struct *last_task_used_math = NULL;
     67struct thread_info *current_set[NR_CPUS];
     68
     69/* Idle loop support. */
     70void arch_cpu_idle(void)
     71{
     72	if (sparc_idle)
     73		(*sparc_idle)();
     74	raw_local_irq_enable();
     75}
     76
     77/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
     78void machine_halt(void)
     79{
     80	local_irq_enable();
     81	mdelay(8);
     82	local_irq_disable();
     83	prom_halt();
     84	panic("Halt failed!");
     85}
     86
     87void machine_restart(char * cmd)
     88{
     89	char *p;
     90	
     91	local_irq_enable();
     92	mdelay(8);
     93	local_irq_disable();
     94
     95	p = strchr (reboot_command, '\n');
     96	if (p) *p = 0;
     97	if (cmd)
     98		prom_reboot(cmd);
     99	if (*reboot_command)
    100		prom_reboot(reboot_command);
    101	prom_feval ("reset");
    102	panic("Reboot failed!");
    103}
    104
    105void machine_power_off(void)
    106{
    107	if (auxio_power_register &&
    108	    (!of_node_is_type(of_console_device, "serial") || scons_pwroff)) {
    109		u8 power_register = sbus_readb(auxio_power_register);
    110		power_register |= AUXIO_POWER_OFF;
    111		sbus_writeb(power_register, auxio_power_register);
    112	}
    113
    114	machine_halt();
    115}
    116
    117void show_regs(struct pt_regs *r)
    118{
    119	struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
    120
    121	show_regs_print_info(KERN_DEFAULT);
    122
    123        printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
    124	       r->psr, r->pc, r->npc, r->y, print_tainted());
    125	printk("PC: <%pS>\n", (void *) r->pc);
    126	printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
    127	       r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
    128	       r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
    129	printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
    130	       r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
    131	       r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
    132	printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
    133
    134	printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
    135	       rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
    136	       rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
    137	printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
    138	       rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
    139	       rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
    140}
    141
    142/*
    143 * The show_stack() is external API which we do not use ourselves.
    144 * The oops is printed in die_if_kernel.
    145 */
    146void show_stack(struct task_struct *tsk, unsigned long *_ksp, const char *loglvl)
    147{
    148	unsigned long pc, fp;
    149	unsigned long task_base;
    150	struct reg_window32 *rw;
    151	int count = 0;
    152
    153	if (!tsk)
    154		tsk = current;
    155
    156	if (tsk == current && !_ksp)
    157		__asm__ __volatile__("mov	%%fp, %0" : "=r" (_ksp));
    158
    159	task_base = (unsigned long) task_stack_page(tsk);
    160	fp = (unsigned long) _ksp;
    161	do {
    162		/* Bogus frame pointer? */
    163		if (fp < (task_base + sizeof(struct thread_info)) ||
    164		    fp >= (task_base + (PAGE_SIZE << 1)))
    165			break;
    166		rw = (struct reg_window32 *) fp;
    167		pc = rw->ins[7];
    168		printk("%s[%08lx : ", loglvl, pc);
    169		printk("%s%pS ] ", loglvl, (void *) pc);
    170		fp = rw->ins[6];
    171	} while (++count < 16);
    172	printk("%s\n", loglvl);
    173}
    174
    175/*
    176 * Free current thread data structures etc..
    177 */
    178void exit_thread(struct task_struct *tsk)
    179{
    180#ifndef CONFIG_SMP
    181	if (last_task_used_math == tsk) {
    182#else
    183	if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) {
    184#endif
    185		/* Keep process from leaving FPU in a bogon state. */
    186		put_psr(get_psr() | PSR_EF);
    187		fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr,
    188		       &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth);
    189#ifndef CONFIG_SMP
    190		last_task_used_math = NULL;
    191#else
    192		clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU);
    193#endif
    194	}
    195}
    196
    197void flush_thread(void)
    198{
    199	current_thread_info()->w_saved = 0;
    200
    201#ifndef CONFIG_SMP
    202	if(last_task_used_math == current) {
    203#else
    204	if (test_thread_flag(TIF_USEDFPU)) {
    205#endif
    206		/* Clean the fpu. */
    207		put_psr(get_psr() | PSR_EF);
    208		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
    209		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
    210#ifndef CONFIG_SMP
    211		last_task_used_math = NULL;
    212#else
    213		clear_thread_flag(TIF_USEDFPU);
    214#endif
    215	}
    216}
    217
    218static inline struct sparc_stackf __user *
    219clone_stackframe(struct sparc_stackf __user *dst,
    220		 struct sparc_stackf __user *src)
    221{
    222	unsigned long size, fp;
    223	struct sparc_stackf *tmp;
    224	struct sparc_stackf __user *sp;
    225
    226	if (get_user(tmp, &src->fp))
    227		return NULL;
    228
    229	fp = (unsigned long) tmp;
    230	size = (fp - ((unsigned long) src));
    231	fp = (unsigned long) dst;
    232	sp = (struct sparc_stackf __user *)(fp - size); 
    233
    234	/* do_fork() grabs the parent semaphore, we must release it
    235	 * temporarily so we can build the child clone stack frame
    236	 * without deadlocking.
    237	 */
    238	if (__copy_user(sp, src, size))
    239		sp = NULL;
    240	else if (put_user(fp, &sp->fp))
    241		sp = NULL;
    242
    243	return sp;
    244}
    245
    246/* Copy a Sparc thread.  The fork() return value conventions
    247 * under SunOS are nothing short of bletcherous:
    248 * Parent -->  %o0 == childs  pid, %o1 == 0
    249 * Child  -->  %o0 == parents pid, %o1 == 1
    250 *
    251 * NOTE: We have a separate fork kpsr/kwim because
    252 *       the parent could change these values between
    253 *       sys_fork invocation and when we reach here
    254 *       if the parent should sleep while trying to
    255 *       allocate the task_struct and kernel stack in
    256 *       do_fork().
    257 * XXX See comment above sys_vfork in sparc64. todo.
    258 */
    259extern void ret_from_fork(void);
    260extern void ret_from_kernel_thread(void);
    261
    262int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
    263{
    264	unsigned long clone_flags = args->flags;
    265	unsigned long sp = args->stack;
    266	unsigned long tls = args->tls;
    267	struct thread_info *ti = task_thread_info(p);
    268	struct pt_regs *childregs, *regs = current_pt_regs();
    269	char *new_stack;
    270
    271#ifndef CONFIG_SMP
    272	if(last_task_used_math == current) {
    273#else
    274	if (test_thread_flag(TIF_USEDFPU)) {
    275#endif
    276		put_psr(get_psr() | PSR_EF);
    277		fpsave(&p->thread.float_regs[0], &p->thread.fsr,
    278		       &p->thread.fpqueue[0], &p->thread.fpqdepth);
    279	}
    280
    281	/*
    282	 *  p->thread_info         new_stack   childregs stack bottom
    283	 *  !                      !           !             !
    284	 *  V                      V (stk.fr.) V  (pt_regs)  V
    285	 *  +----- - - - - - ------+===========+=============+
    286	 */
    287	new_stack = task_stack_page(p) + THREAD_SIZE;
    288	new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
    289	childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
    290
    291	/*
    292	 * A new process must start with interrupts disabled, see schedule_tail()
    293	 * and finish_task_switch(). (If we do not do it and if a timer interrupt
    294	 * hits before we unlock and attempts to take the rq->lock, we deadlock.)
    295	 *
    296	 * Thus, kpsr |= PSR_PIL.
    297	 */
    298	ti->ksp = (unsigned long) new_stack;
    299	p->thread.kregs = childregs;
    300
    301	if (unlikely(args->fn)) {
    302		extern int nwindows;
    303		unsigned long psr;
    304		memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
    305		ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
    306		childregs->u_regs[UREG_G1] = (unsigned long) args->fn;
    307		childregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg;
    308		psr = childregs->psr = get_psr();
    309		ti->kpsr = psr | PSR_PIL;
    310		ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows);
    311		return 0;
    312	}
    313	memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
    314	childregs->u_regs[UREG_FP] = sp;
    315	ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
    316	ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
    317	ti->kwim = current->thread.fork_kwim;
    318
    319	if (sp != regs->u_regs[UREG_FP]) {
    320		struct sparc_stackf __user *childstack;
    321		struct sparc_stackf __user *parentstack;
    322
    323		/*
    324		 * This is a clone() call with supplied user stack.
    325		 * Set some valid stack frames to give to the child.
    326		 */
    327		childstack = (struct sparc_stackf __user *)
    328			(sp & ~0xfUL);
    329		parentstack = (struct sparc_stackf __user *)
    330			regs->u_regs[UREG_FP];
    331
    332#if 0
    333		printk("clone: parent stack:\n");
    334		show_stackframe(parentstack);
    335#endif
    336
    337		childstack = clone_stackframe(childstack, parentstack);
    338		if (!childstack)
    339			return -EFAULT;
    340
    341#if 0
    342		printk("clone: child stack:\n");
    343		show_stackframe(childstack);
    344#endif
    345
    346		childregs->u_regs[UREG_FP] = (unsigned long)childstack;
    347	}
    348
    349#ifdef CONFIG_SMP
    350	/* FPU must be disabled on SMP. */
    351	childregs->psr &= ~PSR_EF;
    352	clear_tsk_thread_flag(p, TIF_USEDFPU);
    353#endif
    354
    355	/* Set the return value for the child. */
    356	childregs->u_regs[UREG_I0] = current->pid;
    357	childregs->u_regs[UREG_I1] = 1;
    358
    359	/* Set the return value for the parent. */
    360	regs->u_regs[UREG_I1] = 0;
    361
    362	if (clone_flags & CLONE_SETTLS)
    363		childregs->u_regs[UREG_G7] = tls;
    364
    365	return 0;
    366}
    367
    368unsigned long __get_wchan(struct task_struct *task)
    369{
    370	unsigned long pc, fp, bias = 0;
    371	unsigned long task_base = (unsigned long) task;
    372        unsigned long ret = 0;
    373	struct reg_window32 *rw;
    374	int count = 0;
    375
    376	fp = task_thread_info(task)->ksp + bias;
    377	do {
    378		/* Bogus frame pointer? */
    379		if (fp < (task_base + sizeof(struct thread_info)) ||
    380		    fp >= (task_base + (2 * PAGE_SIZE)))
    381			break;
    382		rw = (struct reg_window32 *) fp;
    383		pc = rw->ins[7];
    384		if (!in_sched_functions(pc)) {
    385			ret = pc;
    386			goto out;
    387		}
    388		fp = rw->ins[6] + bias;
    389	} while (++count < 16);
    390
    391out:
    392	return ret;
    393}
    394