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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 
mm/mmap: fix MAP_FIXED address return on VMA merge
 
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
Raw File
Makefile.modinst 
# SPDX-License-Identifier: GPL-2.0
# ==========================================================================
# Installing modules
# ==========================================================================

PHONY := __modinst
__modinst:

include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include

modules := $(sort $(shell cat $(MODORDER)))

ifeq ($(KBUILD_EXTMOD),)
dst := $(MODLIB)/kernel
else
INSTALL_MOD_DIR ?= extra
dst := $(MODLIB)/$(INSTALL_MOD_DIR)
endif

$(foreach x, % :, $(if $(findstring $x, $(dst)), \
	$(error module installation path cannot contain '$x')))

suffix-y				:=
suffix-$(CONFIG_MODULE_COMPRESS_GZIP)	:= .gz
suffix-$(CONFIG_MODULE_COMPRESS_XZ)	:= .xz
suffix-$(CONFIG_MODULE_COMPRESS_ZSTD)	:= .zst

modules := $(patsubst $(extmod_prefix)%, $(dst)/%$(suffix-y), $(modules))

__modinst: $(modules)
	@:

#
# Installation
#
quiet_cmd_install = INSTALL $@
      cmd_install = mkdir -p $(dir $@); cp $< $@

# Strip
#
# INSTALL_MOD_STRIP, if defined, will cause modules to be stripped after they
# are installed. If INSTALL_MOD_STRIP is '1', then the default option
# --strip-debug will be used. Otherwise, INSTALL_MOD_STRIP value will be used
# as the options to the strip command.
ifdef INSTALL_MOD_STRIP

ifeq ($(INSTALL_MOD_STRIP),1)
strip-option := --strip-debug
else
strip-option := $(INSTALL_MOD_STRIP)
endif

quiet_cmd_strip = STRIP   $@
      cmd_strip = $(STRIP) $(strip-option) $@

else

quiet_cmd_strip =
      cmd_strip = :

endif

#
# Signing
# Don't stop modules_install even if we can't sign external modules.
#
ifeq ($(CONFIG_MODULE_SIG_ALL),y)
sig-key := $(if $(wildcard $(CONFIG_MODULE_SIG_KEY)),,$(srctree)/)$(CONFIG_MODULE_SIG_KEY)
quiet_cmd_sign = SIGN    $@
      cmd_sign = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(sig-key) certs/signing_key.x509 $@ \
                 $(if $(KBUILD_EXTMOD),|| true)
else
quiet_cmd_sign :=
      cmd_sign := :
endif

ifeq ($(modules_sign_only),)

$(dst)/%.ko: $(extmod_prefix)%.ko FORCE
	$(call cmd,install)
	$(call cmd,strip)
	$(call cmd,sign)

else

$(dst)/%.ko: FORCE
	$(call cmd,sign)

endif

#
# Compression
#
quiet_cmd_gzip = GZIP    $@
      cmd_gzip = $(KGZIP) -n -f $<
quiet_cmd_xz = XZ      $@
      cmd_xz = $(XZ) --lzma2=dict=2MiB -f $<
quiet_cmd_zstd = ZSTD    $@
      cmd_zstd = $(ZSTD) -T0 --rm -f -q $<

$(dst)/%.ko.gz: $(dst)/%.ko FORCE
	$(call cmd,gzip)

$(dst)/%.ko.xz: $(dst)/%.ko FORCE
	$(call cmd,xz)

$(dst)/%.ko.zst: $(dst)/%.ko FORCE
	$(call cmd,zstd)

PHONY += FORCE
FORCE:

.PHONY: $(PHONY)
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