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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pgm_check_info.c (5021B)


      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/kernel.h>
      3#include <linux/stdarg.h>
      4#include <linux/string.h>
      5#include <linux/ctype.h>
      6#include <asm/stacktrace.h>
      7#include <asm/boot_data.h>
      8#include <asm/lowcore.h>
      9#include <asm/setup.h>
     10#include <asm/sclp.h>
     11#include <asm/uv.h>
     12#include "boot.h"
     13
     14const char hex_asc[] = "0123456789abcdef";
     15
     16static char *as_hex(char *dst, unsigned long val, int pad)
     17{
     18	char *p, *end = p = dst + max(pad, (int)__fls(val | 1) / 4 + 1);
     19
     20	for (*p-- = 0; p >= dst; val >>= 4)
     21		*p-- = hex_asc[val & 0x0f];
     22	return end;
     23}
     24
     25static char *symstart(char *p)
     26{
     27	while (*p)
     28		p--;
     29	return p + 1;
     30}
     31
     32static noinline char *findsym(unsigned long ip, unsigned short *off, unsigned short *len)
     33{
     34	/* symbol entries are in a form "10000 c4 startup\0" */
     35	char *a = _decompressor_syms_start;
     36	char *b = _decompressor_syms_end;
     37	unsigned long start;
     38	unsigned long size;
     39	char *pivot;
     40	char *endp;
     41
     42	while (a < b) {
     43		pivot = symstart(a + (b - a) / 2);
     44		start = simple_strtoull(pivot, &endp, 16);
     45		size = simple_strtoull(endp + 1, &endp, 16);
     46		if (ip < start) {
     47			b = pivot;
     48			continue;
     49		}
     50		if (ip > start + size) {
     51			a = pivot + strlen(pivot) + 1;
     52			continue;
     53		}
     54		*off = ip - start;
     55		*len = size;
     56		return endp + 1;
     57	}
     58	return NULL;
     59}
     60
     61static noinline char *strsym(void *ip)
     62{
     63	static char buf[64];
     64	unsigned short off;
     65	unsigned short len;
     66	char *p;
     67
     68	p = findsym((unsigned long)ip, &off, &len);
     69	if (p) {
     70		strncpy(buf, p, sizeof(buf));
     71		/* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
     72		p = buf + strnlen(buf, sizeof(buf) - 15);
     73		strcpy(p, "+0x");
     74		p = as_hex(p + 3, off, 0);
     75		strcpy(p, "/0x");
     76		as_hex(p + 3, len, 0);
     77	} else {
     78		as_hex(buf, (unsigned long)ip, 16);
     79	}
     80	return buf;
     81}
     82
     83void decompressor_printk(const char *fmt, ...)
     84{
     85	char buf[1024] = { 0 };
     86	char *end = buf + sizeof(buf) - 1; /* make sure buf is 0 terminated */
     87	unsigned long pad;
     88	char *p = buf;
     89	va_list args;
     90
     91	va_start(args, fmt);
     92	for (; p < end && *fmt; fmt++) {
     93		if (*fmt != '%') {
     94			*p++ = *fmt;
     95			continue;
     96		}
     97		pad = isdigit(*++fmt) ? simple_strtol(fmt, (char **)&fmt, 10) : 0;
     98		switch (*fmt) {
     99		case 's':
    100			p = buf + strlcat(buf, va_arg(args, char *), sizeof(buf));
    101			break;
    102		case 'p':
    103			if (*++fmt != 'S')
    104				goto out;
    105			p = buf + strlcat(buf, strsym(va_arg(args, void *)), sizeof(buf));
    106			break;
    107		case 'l':
    108			if (*++fmt != 'x' || end - p <= max(sizeof(long) * 2, pad))
    109				goto out;
    110			p = as_hex(p, va_arg(args, unsigned long), pad);
    111			break;
    112		case 'x':
    113			if (end - p <= max(sizeof(int) * 2, pad))
    114				goto out;
    115			p = as_hex(p, va_arg(args, unsigned int), pad);
    116			break;
    117		default:
    118			goto out;
    119		}
    120	}
    121out:
    122	va_end(args);
    123	sclp_early_printk(buf);
    124}
    125
    126static noinline void print_stacktrace(void)
    127{
    128	struct stack_info boot_stack = { STACK_TYPE_TASK, (unsigned long)_stack_start,
    129					 (unsigned long)_stack_end };
    130	unsigned long sp = S390_lowcore.gpregs_save_area[15];
    131	bool first = true;
    132
    133	decompressor_printk("Call Trace:\n");
    134	while (!(sp & 0x7) && on_stack(&boot_stack, sp, sizeof(struct stack_frame))) {
    135		struct stack_frame *sf = (struct stack_frame *)sp;
    136
    137		decompressor_printk(first ? "(sp:%016lx [<%016lx>] %pS)\n" :
    138					    " sp:%016lx [<%016lx>] %pS\n",
    139				    sp, sf->gprs[8], (void *)sf->gprs[8]);
    140		if (sf->back_chain <= sp)
    141			break;
    142		sp = sf->back_chain;
    143		first = false;
    144	}
    145}
    146
    147void print_pgm_check_info(void)
    148{
    149	unsigned long *gpregs = (unsigned long *)S390_lowcore.gpregs_save_area;
    150	struct psw_bits *psw = &psw_bits(S390_lowcore.psw_save_area);
    151
    152	decompressor_printk("Linux version %s\n", kernel_version);
    153	if (!is_prot_virt_guest() && early_command_line[0])
    154		decompressor_printk("Kernel command line: %s\n", early_command_line);
    155	decompressor_printk("Kernel fault: interruption code %04x ilc:%x\n",
    156			    S390_lowcore.pgm_code, S390_lowcore.pgm_ilc >> 1);
    157	if (kaslr_enabled)
    158		decompressor_printk("Kernel random base: %lx\n", __kaslr_offset);
    159	decompressor_printk("PSW : %016lx %016lx (%pS)\n",
    160			    S390_lowcore.psw_save_area.mask,
    161			    S390_lowcore.psw_save_area.addr,
    162			    (void *)S390_lowcore.psw_save_area.addr);
    163	decompressor_printk(
    164		"      R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x P:%x AS:%x CC:%x PM:%x RI:%x EA:%x\n",
    165		psw->per, psw->dat, psw->io, psw->ext, psw->key, psw->mcheck,
    166		psw->wait, psw->pstate, psw->as, psw->cc, psw->pm, psw->ri,
    167		psw->eaba);
    168	decompressor_printk("GPRS: %016lx %016lx %016lx %016lx\n",
    169			    gpregs[0], gpregs[1], gpregs[2], gpregs[3]);
    170	decompressor_printk("      %016lx %016lx %016lx %016lx\n",
    171			    gpregs[4], gpregs[5], gpregs[6], gpregs[7]);
    172	decompressor_printk("      %016lx %016lx %016lx %016lx\n",
    173			    gpregs[8], gpregs[9], gpregs[10], gpregs[11]);
    174	decompressor_printk("      %016lx %016lx %016lx %016lx\n",
    175			    gpregs[12], gpregs[13], gpregs[14], gpregs[15]);
    176	print_stacktrace();
    177	decompressor_printk("Last Breaking-Event-Address:\n");
    178	decompressor_printk(" [<%016lx>] %pS\n", (unsigned long)S390_lowcore.pgm_last_break,
    179			    (void *)S390_lowcore.pgm_last_break);
    180}