Buildresult: linus/x86_64-defconfig/x86_64-gcc4.6 built on Apr 6 2018, 08:23

kisskb

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Status:	OK
Date/Time:	Apr 6 2018, 08:23
Duration:	0:01:43.246087
Builder:	ka4
Revision:	kernel.h: Retain constant expression output for max()/min() (`3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91)`
Target:	linus/x86_64-defconfig/x86_64-gcc4.6
Branch:	linus
Compiler:	x86_64-gcc4.6 (x86_64-linux-gcc (GCC) 4.6.3)
Config:	defconfig (download)
Log:	Download original Possible warnings (15) arch/x86/kernel/e820.c:652:2: warning: 'gapstart' may be used uninitialized in this function [-Wuninitialized] mm/vmstat.c:89:5: warning: 'oldval' 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/cgroup/cgroup-v1.c:1268:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] mm/hugetlb.c:1440:5: warning: 'page' 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/rcu/tree.o: warning: objtool: rcu_init()+0x1c5: unreachable instruction sound/hda/hdac_regmap.c:282:16: warning: 'err' may be used uninitialized in this function [-Wuninitialized] drivers/base/regmap/regmap.c:2497:6: warning: 'ret' 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] kernel/trace/trace.o: warning: objtool: tracing_start()+0x6f: unreachable instruction drivers/clk/clk.o: warning: objtool: clk_prepare_unlock()+0x44: unreachable instruction drivers/dma-buf/reservation.c:207:2: warning: 'k' may be used uninitialized in this function [-Wuninitialized] net/mac80211/mlme.c:1352:3: 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 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91^{commit} 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91 already have revision, skipping fetch # git checkout -q -f -B kisskb 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91 # git clean -qxdf # < git log -1 # commit 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91 # Author: Kees Cook <keescook@chromium.org> # Date: Fri Mar 30 18:52:36 2018 -0700 # # kernel.h: Retain constant expression output for max()/min() # # In the effort to remove all VLAs from the kernel[1], it is desirable to # build with -Wvla. However, this warning is overly pessimistic, in that # it is only happy with stack array sizes that are declared as constant # expressions, and not constant values. One case of this is the # evaluation of the max() macro which, due to its construction, ends up # converting constant expression arguments into a constant value result. # # All attempts to rewrite this macro with __builtin_constant_p() failed # with older compilers (e.g. gcc 4.4)[2]. However, Martin Uecker, # constructed[3] a mind-shattering solution that works everywhere. # Cthulhu fhtagn! # # This patch updates the min()/max() macros to evaluate to a constant # expression when called on constant expression arguments. This removes # several false-positive stack VLA warnings from an x86 allmodconfig build # when -Wvla is added: # # $ diff -u before.txt after.txt \| grep ^- # -drivers/input/touchscreen/cyttsp4_core.c:871:2: warning: ISO C90 forbids variable length array ‘ids’ [-Wvla] # -fs/btrfs/tree-checker.c:344:4: warning: ISO C90 forbids variable length array ‘namebuf’ [-Wvla] # -lib/vsprintf.c:747:2: warning: ISO C90 forbids variable length array ‘sym’ [-Wvla] # -net/ipv4/proc.c:403:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla] # -net/ipv6/proc.c:198:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla] # -net/ipv6/proc.c:218:2: warning: ISO C90 forbids variable length array ‘buff64’ [-Wvla] # # This also updates two cases where different enums were being compared # and explicitly casts them to int (which matches the old side-effect of # the single-evaluation code): one in tpm/tpm_tis_core.h, and one in # drm/drm_color_mgmt.c. # # [1] https://lkml.org/lkml/2018/3/7/621 # [2] https://lkml.org/lkml/2018/3/10/170 # [3] https://lkml.org/lkml/2018/3/20/845 # # Co-Developed-by: Linus Torvalds <torvalds@linux-foundation.org> # Co-Developed-by: Martin Uecker <Martin.Uecker@med.uni-goettingen.de> # Signed-off-by: Kees Cook <keescook@chromium.org> # Acked-by: Ingo Molnar <mingo@kernel.org> # Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/gcc-4.6.3-nolibc/x86_64-linux/bin/x86_64-linux-gcc --version # < git log --format=%s --max-count=1 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91 # < make -s -j 10 ARCH=x86 O=/kisskb/build/linus_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 10 ARCH=x86 O=/kisskb/build/linus_x86_64_defconfig_x86_64 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/x86_64-linux/bin/x86_64-linux- /kisskb/src/arch/x86/kernel/e820.c: In function 'e820__setup_pci_gap': /kisskb/src/arch/x86/kernel/e820.c:652:2: warning: 'gapstart' 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/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] /kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount': /kisskb/src/kernel/cgroup/cgroup-v1.c:1268:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1440:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /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] kernel/rcu/tree.o: warning: objtool: rcu_init()+0x1c5: unreachable instruction /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_read': /kisskb/src/drivers/base/regmap/regmap.c:2497:6: warning: 'ret' 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] kernel/trace/trace.o: warning: objtool: tracing_start()+0x6f: unreachable instruction drivers/clk/clk.o: warning: objtool: clk_prepare_unlock()+0x44: unreachable instruction /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 /kisskb/src/net/mac80211/mlme.c: In function 'ieee80211_rx_mgmt_beacon': /kisskb/src/net/mac80211/mlme.c:1352:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/mac80211/mlme.c:1309:6: note: 'pwr_level_cisco' was declared here fs/aio.o: warning: objtool: aio_nr_sub()+0x2d: unreachable instruction Completed OK # rm -rf /kisskb/build/linus_x86_64_defconfig_x86_64 # Build took: 0:01:43.246087

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