Revision a57b70519d1f7c53be98478623652738e5ac70d5 authored by Liam Howlett on 18 October 2022, 19:17:12 UTC, committed by Andrew Morton on 21 October 2022, 04:27:23 UTC
mmap should return the start address of newly mapped area when successful. On a successful merge of a VMA, the return address was changed and thus was violating that expectation from userspace. This is a restoration of functionality provided by 309d08d9b3a3 (mm/mmap.c: fix mmap return value when vma is merged after call_mmap()). For completeness of fixing MAP_FIXED, implement the comments from the previous discussion to never update the address and fail if the address changes. Leaving the error as a WARN_ON() to avoid crashing the kernel. Link: https://lkml.kernel.org/r/20221018191613.4133459-1-Liam.Howlett@oracle.com Link: https://lore.kernel.org/all/Y06yk66SKxlrwwfb@lakrids/ Link: https://lore.kernel.org/all/20201203085350.22624-1-liuzixian4@huawei.com/ Fixes: 4dd1b84140c1 ("mm/mmap: use advanced maple tree API for mmap_region()") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reported-by: Mark Rutland <mark.rutland@arm.com> Cc: Liu Zixian <liuzixian4@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1 parent 1cd916d
gcc_base.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include "gcov.h"
/*
* __gcov_init is called by gcc-generated constructor code for each object
* file compiled with -fprofile-arcs.
*/
void __gcov_init(struct gcov_info *info)
{
static unsigned int gcov_version;
mutex_lock(&gcov_lock);
if (gcov_version == 0) {
gcov_version = gcov_info_version(info);
/*
* Printing gcc's version magic may prove useful for debugging
* incompatibility reports.
*/
pr_info("version magic: 0x%x\n", gcov_version);
}
/*
* Add new profiling data structure to list and inform event
* listener.
*/
gcov_info_link(info);
if (gcov_events_enabled)
gcov_event(GCOV_ADD, info);
mutex_unlock(&gcov_lock);
}
EXPORT_SYMBOL(__gcov_init);
/*
* These functions may be referenced by gcc-generated profiling code but serve
* no function for kernel profiling.
*/
void __gcov_flush(void)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_flush);
void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_add);
void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_single);
void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_delta);
void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_ior);
void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_time_profile);
void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_icall_topn);
void __gcov_exit(void)
{
/* Unused. */
}
EXPORT_SYMBOL(__gcov_exit);
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