Buildresult: powerpc-next/powerpc-allmodconfig+ppc64le/powerpc-gcc5 built on Apr 4 2018, 23:10

kisskb

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Status:	OK
Date/Time:	Apr 4 2018, 23:10
Duration:	0:16:50.537480
Builder:	ka2
Revision:	cxl: Fix possible deadlock when processing page faults from cxllib (`ad7b4e8022b9864c075fe71e1328b1d25cad82f6)`
Target:	powerpc-next/powerpc-allmodconfig+ppc64le/powerpc-gcc5
Branch:	powerpc-next
Compiler:	powerpc-gcc5 (powerpc64le-linux-gcc (GCC) 5.2.0)
Config:	allmodconfig+ppc64le (download)
Log:	Download original Possible warnings (13) arch/powerpc/include/asm/io.h:162:2: warning: 'px_is' may be used uninitialized in this function [-Wmaybe-uninitialized] arch/powerpc/include/asm/io.h:162:2: warning: 'px_cmd' may be used uninitialized in this function [-Wmaybe-uninitialized] drivers/input/joystick/analog.c:176:2: warning: #warning Precise timer not defined for this architecture. [-Wcpp] #warning Precise timer not defined for this architecture. WARNING: vmlinux.o(.text+0x3664): Section mismatch in reference from the variable __boot_from_prom to the function .init.text:prom_init() WARNING: vmlinux.o(.text+0x3944): Section mismatch in reference from the variable start_here_multiplatform to the function .init.text:early_setup() WARNING: vmlinux.o(.text+0x3978): Section mismatch in reference from the variable start_here_common to the function .init.text:start_kernel() WARNING: vmlinux.o(.text+0x282e8): Section mismatch in reference from the function setup_rfi_flush() to the function .init.text:ppc64_bolted_size() WARNING: vmlinux.o(.text+0x28318): Section mismatch in reference from the function setup_rfi_flush() to the function .init.text:memblock_alloc_base() WARNING: vmlinux.o(.text+0x34844c): Section mismatch in reference from the function devm_memremap_pages() to the function .meminit.text:arch_add_memory() WARNING: vmlinux.o(.text+0x348d38): Section mismatch in reference from the function devm_memremap_pages_release() to the function .meminit.text:arch_remove_memory() WARNING: vmlinux.o(.text+0x471a0c): Section mismatch in reference from the function hmm_devmem_release() to the function .meminit.text:arch_remove_memory() WARNING: vmlinux.o(.text+0x471ee8): Section mismatch in reference from the function hmm_devmem_pages_create() to the function .meminit.text:arch_add_memory() Full Log # git rev-parse -q --verify ad7b4e8022b9864c075fe71e1328b1d25cad82f6^{commit} ad7b4e8022b9864c075fe71e1328b1d25cad82f6 already have revision, skipping fetch # git checkout -q -f -B kisskb ad7b4e8022b9864c075fe71e1328b1d25cad82f6 # git clean -qxdf # < git log -1 # commit ad7b4e8022b9864c075fe71e1328b1d25cad82f6 # Author: Frederic Barrat <fbarrat@linux.vnet.ibm.com> # Date: Tue Apr 3 15:54:02 2018 +0200 # # cxl: Fix possible deadlock when processing page faults from cxllib # # cxllib_handle_fault() is called by an external driver when it needs to # have the host resolve page faults for a buffer. The buffer can cover # several pages and VMAs. The function iterates over all the pages used # by the buffer, based on the page size of the VMA. # # To ensure some stability while processing the faults, the thread T1 # grabs the mm->mmap_sem semaphore with read access (R1). However, when # processing a page fault for a single page, one of the underlying # functions, copro_handle_mm_fault(), also grabs the same semaphore with # read access (R2). So the thread T1 takes the semaphore twice. # # If another thread T2 tries to access the semaphore in write mode W1 # (say, because it wants to allocate memory and calls 'brk'), then that # thread T2 will have to wait because there's a reader (R1). If the # thread T1 is processing a new page at that time, it won't get an # automatic grant at R2, because there's now a writer thread # waiting (T2). And we have a deadlock. # # The timeline is: # 1. thread T1 owns the semaphore with read access R1 # 2. thread T2 requests write access W1 and waits # 3. thread T1 requests read access R2 and waits # # The fix is for the thread T1 to release the semaphore R1 once it got # the information it needs from the current VMA. The address space/VMAs # could evolve while T1 iterates over the full buffer, but in the # unlikely case where T1 misses a page, the external driver will raise a # new page fault when retrying the memory access. # # Fixes: 3ced8d730063 ("cxl: Export library to support IBM XSL") # Cc: stable@vger.kernel.org # 4.13+ # Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # < /opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux-gcc --version # < git log --format=%s --max-count=1 ad7b4e8022b9864c075fe71e1328b1d25cad82f6 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_allmodconfig+ppc64le_ppc64le CROSS_COMPILE=/opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux- allmodconfig # Added to kconfig CONFIG_CPU_LITTLE_ENDIAN=y # Added to kconfig CONFIG_BUILD_DOCSRC=n # Added to kconfig CONFIG_MODULE_SIG=n # Added to kconfig CONFIG_SAMPLES=n # yes \n \| make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_allmodconfig+ppc64le_ppc64le CROSS_COMPILE=/opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux- oldconfig yes: standard output: Broken pipe yes: write error # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_allmodconfig+ppc64le_ppc64le CROSS_COMPILE=/opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux- In file included from /kisskb/src/include/linux/io.h:25:0, from /kisskb/src/include/linux/of_address.h:7, from /kisskb/src/drivers/ata/ahci_qoriq.c:18: /kisskb/src/drivers/ata/ahci_qoriq.c: In function 'ahci_qoriq_hardreset': /kisskb/src/arch/powerpc/include/asm/io.h:162:2: warning: 'px_is' may be used uninitialized in this function [-Wmaybe-uninitialized] __asm__ __volatile__("sync;"#insn"%U0%X0 %1,%0" \ ^ /kisskb/src/drivers/ata/ahci_qoriq.c:86:14: note: 'px_is' was declared here u32 px_cmd, px_is, px_val; ^ In file included from /kisskb/src/include/linux/io.h:25:0, from /kisskb/src/include/linux/of_address.h:7, from /kisskb/src/drivers/ata/ahci_qoriq.c:18: /kisskb/src/arch/powerpc/include/asm/io.h:162:2: warning: 'px_cmd' may be used uninitialized in this function [-Wmaybe-uninitialized] __asm__ __volatile__("sync;"#insn"%U0%X0 %1,%0" \ ^ /kisskb/src/drivers/ata/ahci_qoriq.c:86:6: note: 'px_cmd' was declared here u32 px_cmd, px_is, px_val; ^ /kisskb/src/drivers/input/joystick/analog.c:176:2: warning: #warning Precise timer not defined for this architecture. [-Wcpp] #warning Precise timer not defined for this architecture. ^ WARNING: vmlinux.o(.text+0x3664): Section mismatch in reference from the variable __boot_from_prom to the function .init.text:prom_init() The function __boot_from_prom() references the function __init prom_init(). This is often because __boot_from_prom lacks a __init annotation or the annotation of prom_init is wrong. WARNING: vmlinux.o(.text+0x3944): Section mismatch in reference from the variable start_here_multiplatform to the function .init.text:early_setup() The function start_here_multiplatform() references the function __init early_setup(). This is often because start_here_multiplatform lacks a __init annotation or the annotation of early_setup is wrong. WARNING: vmlinux.o(.text+0x3978): Section mismatch in reference from the variable start_here_common to the function .init.text:start_kernel() The function start_here_common() references the function __init start_kernel(). This is often because start_here_common lacks a __init annotation or the annotation of start_kernel is wrong. WARNING: vmlinux.o(.text+0x282e8): Section mismatch in reference from the function setup_rfi_flush() to the function .init.text:ppc64_bolted_size() The function setup_rfi_flush() references the function __init ppc64_bolted_size(). This is often because setup_rfi_flush lacks a __init annotation or the annotation of ppc64_bolted_size is wrong. WARNING: vmlinux.o(.text+0x28318): Section mismatch in reference from the function setup_rfi_flush() to the function .init.text:memblock_alloc_base() The function setup_rfi_flush() references the function __init memblock_alloc_base(). This is often because setup_rfi_flush lacks a __init annotation or the annotation of memblock_alloc_base is wrong. WARNING: vmlinux.o(.text+0x34844c): Section mismatch in reference from the function devm_memremap_pages() to the function .meminit.text:arch_add_memory() The function devm_memremap_pages() references the function __meminit arch_add_memory(). This is often because devm_memremap_pages lacks a __meminit annotation or the annotation of arch_add_memory is wrong. WARNING: vmlinux.o(.text+0x348d38): Section mismatch in reference from the function devm_memremap_pages_release() to the function .meminit.text:arch_remove_memory() The function devm_memremap_pages_release() references the function __meminit arch_remove_memory(). This is often because devm_memremap_pages_release lacks a __meminit annotation or the annotation of arch_remove_memory is wrong. WARNING: vmlinux.o(.text+0x471a0c): Section mismatch in reference from the function hmm_devmem_release() to the function .meminit.text:arch_remove_memory() The function hmm_devmem_release() references the function __meminit arch_remove_memory(). This is often because hmm_devmem_release lacks a __meminit annotation or the annotation of arch_remove_memory is wrong. WARNING: vmlinux.o(.text+0x471ee8): Section mismatch in reference from the function hmm_devmem_pages_create() to the function .meminit.text:arch_add_memory() The function hmm_devmem_pages_create() references the function __meminit arch_add_memory(). This is often because hmm_devmem_pages_create lacks a __meminit annotation or the annotation of arch_add_memory is wrong. Completed OK # rm -rf /kisskb/build/powerpc-next_allmodconfig+ppc64le_ppc64le # Build took: 0:16:50.537480

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