Buildresult: linus/se7619_defconfig/sh4-gcc10 built on Dec 18 2020, 05:48

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Status:	OK
Date/Time:	Dec 18 2020, 05:48
Duration:	0:00:26.509120
Builder:	ka2
Revision:	drm/edid: fix objtool warning in drm_cvt_modes() (`d652d5f1eeeb06046009f4fcb9b4542249526916)`
Target:	linus/se7619_defconfig/sh4-gcc10
Branch:	linus
Compiler:	sh4-gcc10 (sh4-linux-gcc (GCC) 10.1.0 / GNU ld (GNU Binutils) 2.34)
Config:	se7619_defconfig (download)
Log:	Download original Possible warnings (7) <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] arch/sh/kernel/traps.c:183:15: warning: unused variable 'cpu' [-Wunused-variable] drivers/tty/serial/sh-sci.c:2677:19: warning: unused variable 'sport' [-Wunused-variable] Full Log # git rev-parse -q --verify d652d5f1eeeb06046009f4fcb9b4542249526916^{commit} d652d5f1eeeb06046009f4fcb9b4542249526916 already have revision, skipping fetch # git checkout -q -f -B kisskb d652d5f1eeeb06046009f4fcb9b4542249526916 # git clean -qxdf # < git log -1 # commit d652d5f1eeeb06046009f4fcb9b4542249526916 # Author: Linus Torvalds <torvalds@linux-foundation.org> # Date: Thu Dec 17 09:27:57 2020 -0800 # # drm/edid: fix objtool warning in drm_cvt_modes() # # Commit 991fcb77f490 ("drm/edid: Fix uninitialized variable in # drm_cvt_modes()") just replaced one warning with another. # # The original warning about a possibly uninitialized variable was due to # the compiler not being smart enough to see that the case statement # actually enumerated all possible cases. And the initial fix was just to # add a "default" case that had a single "unreachable()", just to tell the # compiler that that situation cannot happen. # # However, that doesn't actually fix the fundamental reason for the # problem: the compiler still doesn't see that the existing case # statements enumerate all possibilities, so the compiler will still # generate code to jump to that unreachable case statement. It just won't # complain about an uninitialized variable any more. # # So now the compiler generates code to our inline asm marker that we told # it would not fall through, and end end result is basically random. We # have created a bridge to nowhere. # # And then, depending on the random details of just exactly what the # compiler ends up doing, 'objtool' might end up complaining about the # conditional branches (for conditions that cannot happen, and that thus # will never be taken - but if the compiler was not smart enough to figure # that out, we can't expect objtool to do so) going off in the weeds. # # So depending on how the compiler has laid out the result, you might see # something like this: # # drivers/gpu/drm/drm_edid.o: warning: objtool: do_cvt_mode() falls through to next function drm_mode_detailed.isra.0() # # and now you have a truly inscrutable warning that makes no sense at all # unless you start looking at whatever random code the compiler happened # to generate for our bare "unreachable()" statement. # # IOW, don't use "unreachable()" unless you have an _active_ operation # that generates code that actually makes it obvious that something is not # reachable (ie an UD instruction or similar). # # Solve the "compiler isn't smart enough" problem by just marking one of # the cases as "default", so that even when the compiler doesn't otherwise # see that we've enumerated all cases, the compiler will feel happy and # safe about there always being a valid case that initializes the 'width' # variable. # # This also generates better code, since now the compiler doesn't generate # comparisons for five different possibilities (the four real ones and the # one that can't happen), but just for the three real ones and "the rest" # (which is that last one). # # A smart enough compiler that sees that we cover all the cases won't care. # # Cc: Lyude Paul <lyude@redhat.com> # Cc: Ilia Mirkin <imirkin@alum.mit.edu> # Cc: Josh Poimboeuf <jpoimboe@redhat.com> # Cc: Peter Zijlstra <peterz@infradead.org> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/korg/gcc-10.1.0-nolibc/sh4-linux/bin/sh4-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-10.1.0-nolibc/sh4-linux/bin/sh4-linux-ld --version # < git log --format=%s --max-count=1 d652d5f1eeeb06046009f4fcb9b4542249526916 # < make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc10 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-10.1.0-nolibc/sh4-linux/bin/sh4-linux- se7619_defconfig # < make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc10 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-10.1.0-nolibc/sh4-linux/bin/sh4-linux- help # make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc10 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-10.1.0-nolibc/sh4-linux/bin/sh4-linux- olddefconfig # make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc10 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-10.1.0-nolibc/sh4-linux/bin/sh4-linux- Generating include/generated/machtypes.h <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] In file included from /kisskb/src/arch/sh/include/asm/hw_irq.h:6, from /kisskb/src/include/linux/irq.h:589, from /kisskb/src/include/asm-generic/hardirq.h:17, from /kisskb/src/arch/sh/include/asm/hardirq.h:9, from /kisskb/src/include/linux/hardirq.h:10, from /kisskb/src/include/linux/interrupt.h:11, from /kisskb/src/include/linux/serial_core.h:13, from /kisskb/src/include/linux/serial_sci.h:6, from /kisskb/src/arch/sh/kernel/cpu/sh2/setup-sh7619.c:11: /kisskb/src/include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] 100 \| #define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(a) \| ^ /kisskb/src/include/linux/sh_intc.h:105:24: note: in expansion of macro '_INTC_ARRAY' 105 \| _INTC_ARRAY(vectors), _INTC_ARRAY(groups), \ \| ^~~~~~~~~~~ /kisskb/src/include/linux/sh_intc.h:124:8: note: in expansion of macro 'INTC_HW_DESC' 124 \| .hw = INTC_HW_DESC(vectors, groups, mask_regs, \ \| ^~~~~~~~~~~~ /kisskb/src/arch/sh/kernel/cpu/sh2/setup-sh7619.c:58:8: note: in expansion of macro 'DECLARE_INTC_DESC' 58 \| static DECLARE_INTC_DESC(intc_desc, "sh7619", vectors, NULL, \| ^~~~~~~~~~~~~~~~~ /kisskb/src/include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] 100 \| #define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(a) \| ^ /kisskb/src/include/linux/sh_intc.h:106:2: note: in expansion of macro '_INTC_ARRAY' 106 \| _INTC_ARRAY(mask_regs), _INTC_ARRAY(prio_regs), \ \| ^~~~~~~~~~~ /kisskb/src/include/linux/sh_intc.h:124:8: note: in expansion of macro 'INTC_HW_DESC' 124 \| .hw = INTC_HW_DESC(vectors, groups, mask_regs, \ \| ^~~~~~~~~~~~ /kisskb/src/arch/sh/kernel/cpu/sh2/setup-sh7619.c:58:8: note: in expansion of macro 'DECLARE_INTC_DESC' 58 \| static DECLARE_INTC_DESC(intc_desc, "sh7619", vectors, NULL, \| ^~~~~~~~~~~~~~~~~ /kisskb/src/include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] 100 \| #define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(a) \| ^ /kisskb/src/include/linux/sh_intc.h:107:2: note: in expansion of macro '_INTC_ARRAY' 107 \| _INTC_ARRAY(sense_regs), _INTC_ARRAY(ack_regs), \ \| ^~~~~~~~~~~ /kisskb/src/include/linux/sh_intc.h:124:8: note: in expansion of macro 'INTC_HW_DESC' 124 \| .hw = INTC_HW_DESC(vectors, groups, mask_regs, \ \| ^~~~~~~~~~~~ /kisskb/src/arch/sh/kernel/cpu/sh2/setup-sh7619.c:58:8: note: in expansion of macro 'DECLARE_INTC_DESC' 58 \| static DECLARE_INTC_DESC(intc_desc, "sh7619", vectors, NULL, \| ^~~~~~~~~~~~~~~~~ /kisskb/src/include/linux/sh_intc.h:100:63: warning: division 'sizeof (void ) / sizeof (void)' does not compute the number of array elements [-Wsizeof-pointer-div] 100 \| #define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(a) \| ^ /kisskb/src/include/linux/sh_intc.h:107:27: note: in expansion of macro '_INTC_ARRAY' 107 \| _INTC_ARRAY(sense_regs), _INTC_ARRAY(ack_regs), \ \| ^~~~~~~~~~~ /kisskb/src/include/linux/sh_intc.h:124:8: note: in expansion of macro 'INTC_HW_DESC' 124 \| .hw = INTC_HW_DESC(vectors, groups, mask_regs, \ \| ^~~~~~~~~~~~ /kisskb/src/arch/sh/kernel/cpu/sh2/setup-sh7619.c:58:8: note: in expansion of macro 'DECLARE_INTC_DESC' 58 \| static DECLARE_INTC_DESC(intc_desc, "sh7619", vectors, NULL, \| ^~~~~~~~~~~~~~~~~ /kisskb/src/arch/sh/kernel/traps.c: In function 'nmi_trap_handler': /kisskb/src/arch/sh/kernel/traps.c:183:15: warning: unused variable 'cpu' [-Wunused-variable] 183 \| unsigned int cpu = smp_processor_id(); \| ^~~ /kisskb/src/drivers/tty/serial/sh-sci.c: In function 'sci_remap_port': /kisskb/src/drivers/tty/serial/sh-sci.c:2677:19: warning: unused variable 'sport' [-Wunused-variable] 2677 \| struct sci_port *sport = to_sci_port(port); \| ^~~~~ Completed OK # rm -rf /kisskb/build/linus_se7619_defconfig_sh4-gcc10 # Build took: 0:00:26.509120

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