linux-next/include/asm-generic/early_ioremap.h
Guo Weikang d60b6c803c mm/early_ioremap: add null pointer checks to prevent NULL-pointer dereference
The early_ioremap interface can fail and return NULL in certain cases.  To
prevent NULL-pointer dereference crashes, fixed issues in the acpi_extlog
and copy_early_mem interfaces, improving robustness when handling early
memory.

Link: https://lkml.kernel.org/r/20241212101004.1544070-1-guoweikang.kernel@gmail.com
Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-18 19:51:03 -08:00

48 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_EARLY_IOREMAP_H_
#define _ASM_EARLY_IOREMAP_H_
#include <linux/types.h>
/*
* early_ioremap() and early_iounmap() are for temporary early boot-time
* mappings, before the real ioremap() is functional.
*/
extern void __iomem *early_ioremap(resource_size_t phys_addr,
unsigned long size);
extern void *early_memremap(resource_size_t phys_addr,
unsigned long size);
extern void *early_memremap_ro(resource_size_t phys_addr,
unsigned long size);
extern void *early_memremap_prot(resource_size_t phys_addr,
unsigned long size, unsigned long prot_val);
extern void early_iounmap(void __iomem *addr, unsigned long size);
extern void early_memunmap(void *addr, unsigned long size);
#if defined(CONFIG_GENERIC_EARLY_IOREMAP) && defined(CONFIG_MMU)
/* Arch-specific initialization */
extern void early_ioremap_init(void);
/* Generic initialization called by architecture code */
extern void early_ioremap_setup(void);
/*
* Called as last step in paging_init() so library can act
* accordingly for subsequent map/unmap requests.
*/
extern void early_ioremap_reset(void);
/*
* Early copy from unmapped memory to kernel mapped memory.
*/
extern int copy_from_early_mem(void *dest, phys_addr_t src,
unsigned long size);
#else
static inline void early_ioremap_init(void) { }
static inline void early_ioremap_setup(void) { }
static inline void early_ioremap_reset(void) { }
#endif
#endif /* _ASM_EARLY_IOREMAP_H_ */