cregit-Linux how code gets into the kernel

Release 4.14 arch/s390/boot/compressed/misc.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Definitions and wrapper functions for kernel decompressor
 *
 * Copyright IBM Corp. 2010
 *
 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/sclp.h>
#include <asm/ipl.h>
#include "sizes.h"

/*
 * gzip declarations
 */

#define STATIC static


#undef memset

#undef memcpy

#undef memmove

#define memmove memmove

#define memzero(s, n) memset((s), 0, (n))

/* Symbols defined by linker scripts */
extern char input_data[];
extern int input_len;
extern char _text, _end;
extern char _bss, _ebss;

static void error(char *m);


static unsigned long free_mem_ptr;

static unsigned long free_mem_end_ptr;

#ifdef CONFIG_HAVE_KERNEL_BZIP2

#define HEAP_SIZE	0x400000
#else

#define HEAP_SIZE	0x10000
#endif

#ifdef CONFIG_KERNEL_GZIP
#include "../../../../lib/decompress_inflate.c"
#endif

#ifdef CONFIG_KERNEL_BZIP2
#include "../../../../lib/decompress_bunzip2.c"
#endif

#ifdef CONFIG_KERNEL_LZ4
#include "../../../../lib/decompress_unlz4.c"
#endif

#ifdef CONFIG_KERNEL_LZMA
#include "../../../../lib/decompress_unlzma.c"
#endif

#ifdef CONFIG_KERNEL_LZO
#include "../../../../lib/decompress_unlzo.c"
#endif

#ifdef CONFIG_KERNEL_XZ
#include "../../../../lib/decompress_unxz.c"
#endif


static int puts(const char *s) { sclp_early_printk(s); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Schwidefsky1894.74%266.67%
Heiko Carstens15.26%133.33%
Total19100.00%3100.00%


void *memset(void *s, int c, size_t n) { char *xs; xs = s; while (n--) *xs++ = c; return s; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Schwidefsky3694.74%150.00%
Heiko Carstens25.26%150.00%
Total38100.00%2100.00%


void *memcpy(void *dest, const void *src, size_t n) { const char *s = src; char *d = dest; while (n--) *d++ = *s++; return dest; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Carstens3165.96%150.00%
Martin Schwidefsky1634.04%150.00%
Total47100.00%2100.00%


void *memmove(void *dest, const void *src, size_t n) { const char *s = src; char *d = dest; if (d <= s) { while (n--) *d++ = *s++; } else { d += n; s += n; while (n--) *--d = *--s; } return dest; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Schwidefsky4354.43%150.00%
Heiko Carstens3645.57%150.00%
Total79100.00%2100.00%


static void error(char *x) { unsigned long long psw = 0x000a0000deadbeefULL; puts("\n\n"); puts(x); puts("\n\n -- System halted"); asm volatile("lpsw %0" : : "Q" (psw)); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Schwidefsky35100.00%1100.00%
Total35100.00%1100.00%

/* * Safe guard the ipl parameter block against a memory area that will be * overwritten. The validity check for the ipl parameter block is complex * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to * the ipl parameter block intersects with the passed memory area we can * safely assume that we can read from that memory. In that case just copy * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter * block. */
static void check_ipl_parmblock(void *start, unsigned long size) { void *src, *dst; src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr; if (src + PAGE_SIZE <= start || src >= start + size) return; dst = (void *) IPL_PARMBLOCK_ORIGIN; memmove(dst, src, PAGE_SIZE); S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Schwidefsky73100.00%1100.00%
Total73100.00%1100.00%


unsigned long decompress_kernel(void) { void *output, *kernel_end; output = (void *) ALIGN((unsigned long) &_end + HEAP_SIZE, PAGE_SIZE); kernel_end = output + SZ__bss_start; check_ipl_parmblock((void *) 0, (unsigned long) kernel_end); #ifdef CONFIG_BLK_DEV_INITRD /* * Move the initrd right behind the end of the decompressed * kernel image. This also prevents initrd corruption caused by * bss clearing since kernel_end will always be located behind the * current bss section.. */ if (INITRD_START && INITRD_SIZE && kernel_end > (void *) INITRD_START) { check_ipl_parmblock(kernel_end, INITRD_SIZE); memmove(kernel_end, (void *) INITRD_START, INITRD_SIZE); INITRD_START = (unsigned long) kernel_end; } #endif /* * Clear bss section. free_mem_ptr and free_mem_end_ptr need to be * initialized afterwards since they reside in bss. */ memset(&_bss, 0, &_ebss - &_bss); free_mem_ptr = (unsigned long) &_end; free_mem_end_ptr = free_mem_ptr + HEAP_SIZE; puts("Uncompressing Linux... "); __decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error); puts("Ok, booting the kernel.\n"); return (unsigned long) output; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Schwidefsky11063.95%360.00%
Marcelo H. Cerri5934.30%120.00%
Yinghai Lu31.74%120.00%
Total172100.00%5100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Martin Schwidefsky44773.04%428.57%
Heiko Carstens9816.01%535.71%
Marcelo H. Cerri599.64%17.14%
Chen Gang S30.49%17.14%
Yinghai Lu30.49%17.14%
Greg Kroah-Hartman10.16%17.14%
Linus Torvalds10.16%17.14%
Total612100.00%14100.00%
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