include ../scripts/Makefile.include
include ../scripts/Makefile.arch

ifeq ($(ARCH),x86_64)
ARCH := x86
endif

# always use the host compiler
CC = gcc
LD = ld
AR = ar

ifeq ($(srctree),)
srctree := $(patsubst %/,%,$(dir $(CURDIR)))
srctree := $(patsubst %/,%,$(dir $(srctree)))
endif

SUBCMD_SRCDIR		= $(srctree)/tools/lib/subcmd/
LIBSUBCMD_OUTPUT	= $(if $(OUTPUT),$(OUTPUT),$(CURDIR)/)
LIBSUBCMD		= $(LIBSUBCMD_OUTPUT)libsubcmd.a

OBJTOOL    := $(OUTPUT)objtool
OBJTOOL_IN := $(OBJTOOL)-in.o

all: $(OBJTOOL)

INCLUDES := -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi
CFLAGS   += -Wall -Werror $(EXTRA_WARNINGS) -fomit-frame-pointer -O2 -g $(INCLUDES)
LDFLAGS  += -lelf $(LIBSUBCMD)

# Allow old libelf to be used:
elfshdr := $(shell echo '\#include <libelf.h>' | $(CC) $(CFLAGS) -x c -E - | grep elf_getshdr)
CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED)

AWK = awk
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include

$(OBJTOOL_IN): fixdep FORCE
	@$(MAKE) $(build)=objtool

# Busybox's diff doesn't have -I, avoid warning in that case
#
$(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN)
	@(diff -I 2>&1 | grep -q 'option requires an argument' && \
	test -d ../../kernel -a -d ../../tools -a -d ../objtool && (( \
	diff -I'^#include' arch/x86/insn/insn.c ../../arch/x86/lib/insn.c >/dev/null && \
	diff -I'^#include' arch/x86/insn/inat.c ../../arch/x86/lib/inat.c >/dev/null && \
	diff arch/x86/insn/x86-opcode-map.txt ../../arch/x86/lib/x86-opcode-map.txt >/dev/null && \
	diff arch/x86/insn/gen-insn-attr-x86.awk ../../arch/x86/tools/gen-insn-attr-x86.awk >/dev/null && \
	diff -I'^#include' arch/x86/insn/insn.h ../../arch/x86/include/asm/insn.h >/dev/null && \
	diff -I'^#include' arch/x86/insn/inat.h ../../arch/x86/include/asm/inat.h >/dev/null && \
	diff -I'^#include' arch/x86/insn/inat_types.h ../../arch/x86/include/asm/inat_types.h >/dev/null) \
	|| echo "warning: objtool: x86 instruction decoder differs from kernel" >&2 )) || true
	$(QUIET_LINK)$(CC) $(OBJTOOL_IN) $(LDFLAGS) -o $@


$(LIBSUBCMD): fixdep FORCE
	$(Q)$(MAKE) -C $(SUBCMD_SRCDIR) OUTPUT=$(LIBSUBCMD_OUTPUT)

clean:
	$(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL)
	$(Q)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
	$(Q)$(RM) $(OUTPUT)arch/x86/insn/inat-tables.c $(OUTPUT)fixdep

FORCE:

.PHONY: clean FORCE
n>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/trace?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>trace</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>events</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='3895dbf8985f656675b5bde610723a29cbce3fa7'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Eric W. Biederman &lt;ebiederm@xmission.com&gt;</td><td class='right'>2017-01-03 14:18:43 +1300</td></tr>
<tr><th>committer</th><td>Eric W. Biederman &lt;ebiederm@xmission.com&gt;</td><td class='right'>2017-01-10 13:34:43 +1300</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>3895dbf8985f656675b5bde610723a29cbce3fa7</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/trace/events?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>91d4517f09918fd573998eb40b8f35f08ed1c470</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/trace/events?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>include/trace/events</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?id=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>0c744ea4f77d72b3dcebb7a8f2684633ec79be88</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/trace/events?id=3895dbf8985f656675b5bde610723a29cbce3fa7&amp;id2=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>diff</a>)</td></tr></table>
<div class='commit-subject'>mnt: Protect the mountpoint hashtable with mount_lock</div><div class='commit-msg'>Protecting the mountpoint hashtable with namespace_sem was sufficient
until a call to umount_mnt was added to mntput_no_expire.  At which
point it became possible for multiple calls of put_mountpoint on
the same hash chain to happen on the same time.

Kristen Johansen &lt;kjlx@templeofstupid.com&gt; reported:
&gt; This can cause a panic when simultaneous callers of put_mountpoint
&gt; attempt to free the same mountpoint.  This occurs because some callers
&gt; hold the mount_hash_lock, while others hold the namespace lock.  Some
&gt; even hold both.
&gt;
&gt; In this submitter's case, the panic manifested itself as a GP fault in
&gt; put_mountpoint() when it called hlist_del() and attempted to dereference
&gt; a m_hash.pprev that had been poisioned by another thread.

Al Viro observed that the simple fix is to switch from using the namespace_sem
to the mount_lock to protect the mountpoint hash table.

I have taken Al's suggested patch moved put_mountpoint in pivot_root
(instead of taking mount_lock an additional time), and have replaced
new_mountpoint with get_mountpoint a function that does the hash table
lookup and addition under the mount_lock.   The introduction of get_mounptoint
ensures that only the mount_lock is needed to manipulate the mountpoint
hashtable.

d_set_mounted is modified to only set DCACHE_MOUNTED if it is not
already set.  This allows get_mountpoint to use the setting of
DCACHE_MOUNTED to ensure adding a struct mountpoint for a dentry
happens exactly once.

Cc: stable@vger.kernel.org
Fixes: ce07d891a089 ("mnt: Honor MNT_LOCKED when detaching mounts")
Reported-by: Krister Johansen &lt;kjlx@templeofstupid.com&gt;
Suggested-by: Al Viro &lt;viro@ZenIV.linux.org.uk&gt;
Acked-by: Al Viro &lt;viro@ZenIV.linux.org.uk&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>Diffstat</a> (limited to 'include/trace/events')</div><table summary='diffstat' class='diffstat'>