linux/include/asm-generic/error-injection.h
Benjamin Poirier af3b854492 mm/page_alloc.c: allow error injection
Model call chain after should_failslab().  Likewise, we can now use a
kprobe to override the return value of should_fail_alloc_page() and inject
allocation failures into alloc_page*().

This will allow injecting allocation failures using the BCC tools even
without building kernel with CONFIG_FAIL_PAGE_ALLOC and booting it with a
fail_page_alloc= parameter, which incurs some overhead even when failures
are not being injected.  On the other hand, this patch adds an
unconditional call to should_fail_alloc_page() from page allocation
hotpath.  That overhead should be rather negligible with
CONFIG_FAIL_PAGE_ALLOC=n when there's no kprobe attached, though.

[vbabka@suse.cz: changelog addition]
Link: http://lkml.kernel.org/r/20181214074330.18917-1-bpoirier@suse.com
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:51 -08:00

37 lines
1.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_ERROR_INJECTION_H
#define _ASM_GENERIC_ERROR_INJECTION_H
#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
enum {
EI_ETYPE_NONE, /* Dummy value for undefined case */
EI_ETYPE_NULL, /* Return NULL if failure */
EI_ETYPE_ERRNO, /* Return -ERRNO if failure */
EI_ETYPE_ERRNO_NULL, /* Return -ERRNO or NULL if failure */
EI_ETYPE_TRUE, /* Return true if failure */
};
struct error_injection_entry {
unsigned long addr;
int etype;
};
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
/*
* Whitelist ganerating macro. Specify functions which can be
* error-injectable using this macro.
*/
#define ALLOW_ERROR_INJECTION(fname, _etype) \
static struct error_injection_entry __used \
__attribute__((__section__("_error_injection_whitelist"))) \
_eil_addr_##fname = { \
.addr = (unsigned long)fname, \
.etype = EI_ETYPE_##_etype, \
};
#else
#define ALLOW_ERROR_INJECTION(fname, _etype)
#endif
#endif
#endif /* _ASM_GENERIC_ERROR_INJECTION_H */