# 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 # 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 # Cc: Jiri Kosina # Cc: Masatake YAMATO # Cc: Andrew Morton # Cc: Greg KH # Cc: Peter Zijlstra # Cc: Michal Hocko # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 574823bfab82d9d8fa47f422778043fbb4b4f50e # < make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_ppc44x_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ppc44x_defconfig # make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_ppc44x_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /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/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/bridge/br_netlink.c: In function 'br_afspec.isra.35': /kisskb/src/net/bridge/br_netlink.c:652:7: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /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:1753:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] /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/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here /kisskb/src/arch/powerpc/boot/dts/katmai.dts:322.26-361.5: Warning (pci_bridge): /plb/pciex@d00000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/katmai.dts:363.26-402.5: Warning (pci_bridge): /plb/pciex@d20000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/katmai.dts:404.26-443.5: Warning (pci_bridge): /plb/pciex@d40000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/katmai.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x53f1cc) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:53 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2681193 Bytes = 2618.35 KiB = 2.56 MiB Load Address: 00000000 Entry Point: 00000000 INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:53 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2713336 Bytes = 2649.74 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006000c8 INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x54f878) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:53 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2712745 Bytes = 2649.17 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006001bc Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:53 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2712264 Bytes = 2648.70 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006014e0 Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:53 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2713306 Bytes = 2649.71 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006014e0 Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:54 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2712916 Bytes = 2649.33 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006014e0 Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:54 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2713168 Bytes = 2649.58 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006014d8 Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:54 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2713340 Bytes = 2649.75 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006014c0 Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:54 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2712821 Bytes = 2649.24 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006014cc Image Name: Linux-4.20.0-g574823bfab82 Created: Mon Jan 7 10:54:54 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2712850 Bytes = 2649.27 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 006014ec Completed OK # rm -rf /kisskb/build/linus_ppc44x_defconfig_powerpc # Build took: 0:01:02.234379