Buildresult: powerpc-next/x86_64-defconfig/x86_64-gcc4.6 built on Jul 20 2018, 01:56

kisskb

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Status:	OK
Date/Time:	Jul 20 2018, 01:56
Duration:	0:00:37.872418
Builder:	ka4
Revision:	powerpc/mm: Don't report PUDs as memory leaks when using kmemleak (`2bc2026269beb0d7923317f5a4a28ce4d5bbc94c)`
Target:	powerpc-next/x86_64-defconfig/x86_64-gcc4.6
Branch:	powerpc-next
Compiler:	x86_64-gcc4.6 (x86_64-linux-gcc (GCC) 4.6.3)
Config:	defconfig (download)
Log:	Download original Possible warnings (16) include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] kernel/printk/printk.c:183:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] kernel/cgroup/cgroup-v1.c:1256:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] arch/x86/kernel/apic/io_apic.c:1033:6: warning: 'irq' may be used uninitialized in this function [-Wuninitialized] kernel/trace/trace.o: warning: objtool: tracing_start()+0x6d: unreachable instruction kernel/rcu/tree.o: warning: objtool: rcu_init()+0x1c5: unreachable instruction drivers/base/regmap/regmap.c:2497:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] sound/hda/hdac_regmap.c:282:16: warning: 'err' may be used uninitialized in this function [-Wuninitialized] drivers/base/regmap/regmap.c:1819:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] mm/vmstat.c:89:5: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized] drivers/dma-buf/reservation.c:207:2: warning: 'k' may be used uninitialized in this function [-Wuninitialized] drivers/clk/clk.o: warning: objtool: clk_prepare_unlock()+0x44: unreachable instruction arch/x86/kernel/e820.c:653:2: warning: 'gapstart' may be used uninitialized in this function [-Wuninitialized] mm/hugetlb.c:1433:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] net/mac80211/mlme.c:1353:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized] fs/aio.o: warning: objtool: aio_nr_sub()+0x2d: unreachable instruction Full Log # git rev-parse -q --verify 2bc2026269beb0d7923317f5a4a28ce4d5bbc94c^{commit} 2bc2026269beb0d7923317f5a4a28ce4d5bbc94c already have revision, skipping fetch # git checkout -q -f -B kisskb 2bc2026269beb0d7923317f5a4a28ce4d5bbc94c # git clean -qxdf # < git log -1 # commit 2bc2026269beb0d7923317f5a4a28ce4d5bbc94c # Author: Michael Ellerman <mpe@ellerman.id.au> # Date: Thu Jul 19 23:36:10 2018 +1000 # # powerpc/mm: Don't report PUDs as memory leaks when using kmemleak # # Paul Menzel reported that kmemleak was producing reports such as: # # unreferenced object 0xc0000000f8b80000 (size 16384): # comm "init", pid 1, jiffies 4294937416 (age 312.240s) # hex dump (first 32 bytes): # 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ # 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ # backtrace: # [<00000000d997deb7>] __pud_alloc+0x80/0x190 # [<0000000087f2e8a3>] move_page_tables+0xbac/0xdc0 # [<00000000091e51c2>] shift_arg_pages+0xc0/0x210 # [<00000000ab88670c>] setup_arg_pages+0x22c/0x2a0 # [<0000000060871529>] load_elf_binary+0x41c/0x1648 # [<00000000ecd9d2d4>] search_binary_handler.part.11+0xbc/0x280 # [<0000000034e0cdd7>] __do_execve_file.isra.13+0x73c/0x940 # [<000000005f953a6e>] sys_execve+0x58/0x70 # [<000000009700a858>] system_call+0x5c/0x70 # # Indicating that a PUD was being leaked. # # However what's really happening is that kmemleak is not able to # recognise the references from the PGD to the PUD, because they are not # fully qualified pointers. # # We can confirm that in xmon, eg: # # Find the task struct for pid 1 "init": # 0:mon> P # task_struct ->thread.ksp PID PPID S P CMD # c0000001fe7c0000 c0000001fe803960 1 0 S 13 systemd # # Dump virtual address 0 to find the PGD: # 0:mon> dv 0 c0000001fe7c0000 # pgd @ 0xc0000000f8b01000 # # Dump the memory of the PGD: # 0:mon> d c0000000f8b01000 # c0000000f8b01000 00000000f8b90000 0000000000000000 \|................\| # c0000000f8b01010 0000000000000000 0000000000000000 \|................\| # c0000000f8b01020 0000000000000000 0000000000000000 \|................\| # c0000000f8b01030 0000000000000000 00000000f8b80000 \|................\| # ^^^^^^^^^^^^^^^^ # # There we can see the reference to our supposedly leaked PUD. But # because it's missing the leading 0xc, kmemleak won't recognise it. # # We can confirm it's still in use by translating an address that is # mapped via it: # 0:mon> dv 7fff94000000 c0000001fe7c0000 # pgd @ 0xc0000000f8b01000 # pgdp @ 0xc0000000f8b01038 = 0x00000000f8b80000 <-- # pudp @ 0xc0000000f8b81ff8 = 0x00000000037c4000 # pmdp @ 0xc0000000037c5ca0 = 0x00000000fbd89000 # ptep @ 0xc0000000fbd89000 = 0xc0800001d5ce0386 # Maps physical address = 0x00000001d5ce0000 # Flags = Accessed Dirty Read Write # # The fix is fairly simple. We need to tell kmemleak to ignore PUD # allocations and never report them as leaks. We can also tell it not to # scan the PGD, because it will never find pointers in there. However it # will still notice if we allocate a PGD and then leak it. # # Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # < /opt/cross/kisskb/gcc-4.6.3-nolibc/x86_64-linux/bin/x86_64-linux-gcc --version # < git log --format=%s --max-count=1 2bc2026269beb0d7923317f5a4a28ce4d5bbc94c # < make -s -j 120 ARCH=x86 O=/kisskb/build/powerpc-next_x86_64_defconfig_x86_64 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/x86_64-linux/bin/x86_64-linux- x86_64_defconfig # make -s -j 120 ARCH=x86 O=/kisskb/build/powerpc-next_x86_64_defconfig_x86_64 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/x86_64-linux/bin/x86_64-linux- /kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter. /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/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:183:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount': /kisskb/src/kernel/cgroup/cgroup-v1.c:1256:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/arch/x86/kernel/apic/io_apic.c: In function 'mp_map_pin_to_irq': /kisskb/src/arch/x86/kernel/apic/io_apic.c:1033:6: warning: 'irq' may be used uninitialized in this function [-Wuninitialized] kernel/trace/trace.o: warning: objtool: tracing_start()+0x6d: unreachable instruction /kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter. kernel/rcu/tree.o: warning: objtool: rcu_init()+0x1c5: unreachable instruction /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2497:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/hda/hdac_regmap.c: In function 'hda_reg_write': /kisskb/src/sound/hda/hdac_regmap.c:282:16: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1819:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/vmstat.c: In function 'sysctl_vm_numa_stat_handler': /kisskb/src/mm/vmstat.c:89:5: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/dma-buf/reservation.c: In function 'reservation_object_add_shared_fence': /kisskb/src/drivers/dma-buf/reservation.c:207:2: warning: 'k' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/dma-buf/reservation.c:160:17: note: 'k' was declared here drivers/clk/clk.o: warning: objtool: clk_prepare_unlock()+0x44: unreachable instruction /kisskb/src/arch/x86/kernel/e820.c: In function 'e820__setup_pci_gap': /kisskb/src/arch/x86/kernel/e820.c:653:2: warning: 'gapstart' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1433:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/mac80211/mlme.c: In function 'ieee80211_rx_mgmt_beacon': /kisskb/src/net/mac80211/mlme.c:1353:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/mac80211/mlme.c:1310:6: note: 'pwr_level_cisco' was declared here fs/aio.o: warning: objtool: aio_nr_sub()+0x2d: unreachable instruction Completed OK # rm -rf /kisskb/build/powerpc-next_x86_64_defconfig_x86_64 # Build took: 0:00:37.872418

© Michael Ellerman 2006-2018.