# git rev-parse -q --verify 574823bfab82d9d8fa47f422778043fbb4b4f50e^{commit}
574823bfab82d9d8fa47f422778043fbb4b4f50e
already have revision, skipping fetch
# git checkout -q -f -B kisskb 574823bfab82d9d8fa47f422778043fbb4b4f50e
# git clean -qxdf
# < git log -1
# commit 574823bfab82d9d8fa47f422778043fbb4b4f50e
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Sat Jan 5 17:50:59 2019 -0800
# 
#     Change mincore() to count "mapped" pages rather than "cached" pages
#     
#     The semantics of what "in core" means for the mincore() system call are
#     somewhat unclear, but Linux has always (since 2.3.52, which is when
#     mincore() was initially done) treated it as "page is available in page
#     cache" rather than "page is mapped in the mapping".
#     
#     The problem with that traditional semantic is that it exposes a lot of
#     system cache state that it really probably shouldn't, and that users
#     shouldn't really even care about.
#     
#     So let's try to avoid that information leak by simply changing the
#     semantics to be that mincore() counts actual mapped pages, not pages
#     that might be cheaply mapped if they were faulted (note the "might be"
#     part of the old semantics: being in the cache doesn't actually guarantee
#     that you can access them without IO anyway, since things like network
#     filesystems may have to revalidate the cache before use).
#     
#     In many ways the old semantics were somewhat insane even aside from the
#     information leak issue.  From the very beginning (and that beginning is
#     a long time ago: 2.3.52 was released in March 2000, I think), the code
#     had a comment saying
#     
#       Later we can get more picky about what "in core" means precisely.
#     
#     and this is that "later".  Admittedly it is much later than is really
#     comfortable.
#     
#     NOTE! This is a real semantic change, and it is for example known to
#     change the output of "fincore", since that program literally does a
#     mmmap without populating it, and then doing "mincore()" on that mapping
#     that doesn't actually have any pages in it.
#     
#     I'm hoping that nobody actually has any workflow that cares, and the
#     info leak is real.
#     
#     We may have to do something different if it turns out that people have
#     valid reasons to want the old semantics, and if we can limit the
#     information leak sanely.
#     
#     Cc: Kevin Easton <kevin@guarana.org>
#     Cc: Jiri Kosina <jikos@kernel.org>
#     Cc: Masatake YAMATO <yamato@redhat.com>
#     Cc: Andrew Morton <akpm@linux-foundation.org>
#     Cc: Greg KH <gregkh@linuxfoundation.org>
#     Cc: Peter Zijlstra <peterz@infradead.org>
#     Cc: Michal Hocko <mhocko@suse.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-ld --version
# < git log --format=%s --max-count=1 574823bfab82d9d8fa47f422778043fbb4b4f50e
# < make -s -j 10 ARCH=m68k O=/kisskb/build/linus_sun3_defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-  sun3_defconfig

WARNING: unmet direct dependencies detected for NEED_MULTIPLE_NODES
  Depends on [n]: DISCONTIGMEM [=n] || NUMA
  Selected by [y]:
  - SINGLE_MEMORY_CHUNK [=y] && MMU [=y]

WARNING: unmet direct dependencies detected for NEED_MULTIPLE_NODES
  Depends on [n]: DISCONTIGMEM [=n] || NUMA
  Selected by [y]:
  - SINGLE_MEMORY_CHUNK [=y] && MMU [=y]

WARNING: unmet direct dependencies detected for NEED_MULTIPLE_NODES
  Depends on [n]: DISCONTIGMEM [=n] || NUMA
  Selected by [y]:
  - SINGLE_MEMORY_CHUNK [=y] && MMU [=y]
# make -s -j 10 ARCH=m68k O=/kisskb/build/linus_sun3_defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-  
<stdin>:1240:2: warning: #warning syscall seccomp not implemented [-Wcpp]
<stdin>:1318:2: warning: #warning syscall pkey_mprotect not implemented [-Wcpp]
<stdin>:1321:2: warning: #warning syscall pkey_alloc not implemented [-Wcpp]
<stdin>:1324:2: warning: #warning syscall pkey_free not implemented [-Wcpp]
<stdin>:1333:2: warning: #warning syscall io_pgetevents not implemented [-Wcpp]
<stdin>:1336:2: warning: #warning syscall rseq not implemented [-Wcpp]
/kisskb/src/arch/m68k/kernel/signal.c: In function 'mangle_kernel_stack':
/kisskb/src/arch/m68k/kernel/signal.c:654:3: warning: variable length array 'buf' is used [-Wvla]
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/ipc/shm.c: In function 'ksys_shmdt':
/kisskb/src/ipc/shm.c:1686:59: warning: 'file' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/acct.c: In function 'acct_pin_kill':
/kisskb/src/kernel/acct.c:177:2: warning: value computed is not used [-Wunused-value]
/kisskb/src/lib/mpi/mpicoder.c: In function 'mpi_read_raw_from_sgl':
/kisskb/src/lib/mpi/mpicoder.c:336:12: warning: 'buff' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/gen_stats.c: In function '__gnet_stats_copy_basic':
/kisskb/src/net/core/gen_stats.c:161:19: warning: 'seq' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/dev.c: In function 'validate_xmit_skb_list':
/kisskb/src/net/core/dev.c:3405:15: warning: 'tail' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/filter.c: In function 'bpf_clear_redirect_map':
/kisskb/src/net/core/filter.c:3469:4: warning: value computed is not used [-Wunused-value]
/kisskb/src/lib/rhashtable.c: In function 'rht_deferred_worker':
/kisskb/src/lib/rhashtable.c:264:2: warning: 'next' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/rhashtable.c:229:28: note: 'next' was declared here
/kisskb/src/drivers/net/ethernet/i825xx/sun3_82586.c: In function 'sun3_82586_timeout':
/kisskb/src/drivers/net/ethernet/i825xx/sun3_82586.c:993:89: warning: array subscript is above array bounds [-Warray-bounds]
/kisskb/src/net/ipv4/ip_output.c: In function '__ip_append_data.isra.40':
/kisskb/src/include/linux/skbuff.h:1338:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/ipv4/ip_output.c:885:14: note: 'extra_uref' was declared here
/kisskb/src/drivers/net/macsec.c: In function 'macsec_del_rxsa':
/kisskb/src/drivers/net/macsec.c:1926:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:1926:2: warning: 'rx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_del_txsa':
/kisskb/src/drivers/net/macsec.c:2003:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2003:2: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_upd_txsa':
/kisskb/src/drivers/net/macsec.c:2068:5: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2068:24: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2069:21: warning: 'secy' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/ocfs2/file.c: In function 'ocfs2_file_write_iter':
/kisskb/src/fs/ocfs2/file.c:2386:3: warning: value computed is not used [-Wunused-value]
/kisskb/src/net/ipv6/ip6_output.c: In function '__ip6_append_data.isra.37':
/kisskb/src/include/linux/skbuff.h:1338:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/ipv6/ip6_output.c:1270:14: note: 'extra_uref' was declared here
/kisskb/src/drivers/net/tun.c: In function 'tun_get_user':
/kisskb/src/drivers/net/tun.c:1843:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c:1533:31: warning: 'linear' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c:1753:46: note: 'linear' was declared here
/kisskb/src/fs/proc/inode.c: In function 'proc_reg_open':
/kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c:339:21: note: 'pdeo' was declared here
/kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char':
/kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/sctp/output.c: In function 'sctp_packet_config':
/kisskb/src/include/net/sock.h:1942:19: warning: 'sk' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/sctp/output.c:94:15: note: 'sk' was declared here
/kisskb/src/fs/posix_acl.c: In function 'get_acl':
/kisskb/src/fs/posix_acl.c:147:3: warning: value computed is not used [-Wunused-value]
Completed OK
# rm -rf /kisskb/build/linus_sun3_defconfig_m68k
# Build took: 0:01:28.851370