Buildresult: powerpc-fixes/ppc64_defconfig+NO_HUGETLB+4K_PAGES/powerpc-gcc12 built on Jul 29 2023, 02:03

kisskb

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Status:	OK
Date/Time:	Jul 29 2023, 02:03
Duration:	0:03:44.128791
Builder:	ka7
Revision:	powerpc/ftrace: Create a dummy stackframe to fix stack unwind (`41a506ef71eb38d94fe133f565c87c3e06ccc072)`
Target:	powerpc-fixes/ppc64_defconfig+NO_HUGETLB+4K_PAGES/powerpc-gcc12
Branch:	powerpc-fixes
Compiler:	powerpc-gcc12 (powerpc64-linux-gcc (GCC) 12.2.0 / GNU ld (GNU Binutils) 2.39)
Config:	ppc64_defconfig+NO_HUGETLB+4K_PAGES (download)
Log:	Download original Possible warnings (1) .config:4938:warning: override: reassigning to symbol PPC_4K_PAGES Full Log # git rev-parse -q --verify 41a506ef71eb38d94fe133f565c87c3e06ccc072^{commit} 41a506ef71eb38d94fe133f565c87c3e06ccc072 already have revision, skipping fetch # git checkout -q -f -B kisskb 41a506ef71eb38d94fe133f565c87c3e06ccc072 # git clean -qxdf # < git log -1 # commit 41a506ef71eb38d94fe133f565c87c3e06ccc072 # Author: Naveen N Rao <naveen@kernel.org> # Date: Wed Jun 21 10:43:49 2023 +0530 # # powerpc/ftrace: Create a dummy stackframe to fix stack unwind # # With ppc64 -mprofile-kernel and ppc32 -pg, profiling instructions to # call into ftrace are emitted right at function entry. The instruction # sequence used is minimal to reduce overhead. Crucially, a stackframe is # not created for the function being traced. This breaks stack unwinding # since the function being traced does not have a stackframe for itself. # As such, it never shows up in the backtrace: # # /sys/kernel/debug/tracing # echo 1 > /proc/sys/kernel/stack_tracer_enabled # /sys/kernel/debug/tracing # cat stack_trace # Depth Size Location (17 entries) # ----- ---- -------- # 0) 4144 32 ftrace_call+0x4/0x44 # 1) 4112 432 get_page_from_freelist+0x26c/0x1ad0 # 2) 3680 496 __alloc_pages+0x290/0x1280 # 3) 3184 336 __folio_alloc+0x34/0x90 # 4) 2848 176 vma_alloc_folio+0xd8/0x540 # 5) 2672 272 __handle_mm_fault+0x700/0x1cc0 # 6) 2400 208 handle_mm_fault+0xf0/0x3f0 # 7) 2192 80 ___do_page_fault+0x3e4/0xbe0 # 8) 2112 160 do_page_fault+0x30/0xc0 # 9) 1952 256 data_access_common_virt+0x210/0x220 # 10) 1696 400 0xc00000000f16b100 # 11) 1296 384 load_elf_binary+0x804/0x1b80 # 12) 912 208 bprm_execve+0x2d8/0x7e0 # 13) 704 64 do_execveat_common+0x1d0/0x2f0 # 14) 640 160 sys_execve+0x54/0x70 # 15) 480 64 system_call_exception+0x138/0x350 # 16) 416 416 system_call_common+0x160/0x2c4 # # Fix this by having ftrace create a dummy stackframe for the function # being traced. With this, backtraces now capture the function being # traced: # # /sys/kernel/debug/tracing # cat stack_trace # Depth Size Location (17 entries) # ----- ---- -------- # 0) 3888 32 _raw_spin_trylock+0x8/0x70 # 1) 3856 576 get_page_from_freelist+0x26c/0x1ad0 # 2) 3280 64 __alloc_pages+0x290/0x1280 # 3) 3216 336 __folio_alloc+0x34/0x90 # 4) 2880 176 vma_alloc_folio+0xd8/0x540 # 5) 2704 416 __handle_mm_fault+0x700/0x1cc0 # 6) 2288 96 handle_mm_fault+0xf0/0x3f0 # 7) 2192 48 ___do_page_fault+0x3e4/0xbe0 # 8) 2144 192 do_page_fault+0x30/0xc0 # 9) 1952 608 data_access_common_virt+0x210/0x220 # 10) 1344 16 0xc0000000334bbb50 # 11) 1328 416 load_elf_binary+0x804/0x1b80 # 12) 912 64 bprm_execve+0x2d8/0x7e0 # 13) 848 176 do_execveat_common+0x1d0/0x2f0 # 14) 672 192 sys_execve+0x54/0x70 # 15) 480 64 system_call_exception+0x138/0x350 # 16) 416 416 system_call_common+0x160/0x2c4 # # This results in two additional stores in the ftrace entry code, but # produces reliable backtraces. # # Fixes: 153086644fd1 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI") # Cc: stable@vger.kernel.org # Signed-off-by: Naveen N Rao <naveen@kernel.org> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # Link: https://msgid.link/20230621051349.759567-1-naveen@kernel.org # < /opt/cross/kisskb/korg/gcc-12.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-12.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 41a506ef71eb38d94fe133f565c87c3e06ccc072 # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc64_defconfig+NO_HUGETLB+4K_PAGES_powerpc-gcc12 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-12.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ppc64_defconfig # Added to kconfig CONFIG_PPC_64K_PAGES=n # Added to kconfig CONFIG_PPC_4K_PAGES=y # Added to kconfig CONFIG_HUGETLBFS=n # < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc64_defconfig+NO_HUGETLB+4K_PAGES_powerpc-gcc12 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-12.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc64_defconfig+NO_HUGETLB+4K_PAGES_powerpc-gcc12 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-12.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig .config:4938:warning: override: reassigning to symbol PPC_4K_PAGES # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc64_defconfig+NO_HUGETLB+4K_PAGES_powerpc-gcc12 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-12.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- Completed OK # rm -rf /kisskb/build/powerpc-fixes_ppc64_defconfig+NO_HUGETLB+4K_PAGES_powerpc-gcc12 # Build took: 0:03:44.128791

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