Le 21/03/2022 à 09:19, Naveen N. Rao a écrit : > Christophe Leroy wrote: >> >> >> Le 18/03/2022 à 11:51, Sathvika Vasireddy a écrit : >>> This patch adds 'mcount' as a subcommand to objtool, and enables >>> the same for x86. objtool is built if CONFIG_FTRACE_MCOUNT_USE_OBJTOOL >>> is selected. Additionally, architectures can select HAVE_NOP_MCOUNT >>> if they choose to nop out mcount call sites. If that config option is >>> selected, then --mnop is passed as an option to 'objtool mcount' >>> >>> Signed-off-by: Sathvika Vasireddy <s...@linux.ibm.com> >>> --- >>> Makefile | 6 ++ >>> arch/x86/Kconfig | 3 +- >>> scripts/Makefile.build | 12 +++ >>> tools/objtool/Build | 2 + >>> tools/objtool/Makefile | 4 +- >>> tools/objtool/builtin-mcount.c | 74 +++++++++++++ >>> tools/objtool/include/objtool/builtin.h | 4 +- >>> tools/objtool/include/objtool/objtool.h | 1 + >>> tools/objtool/mcount.c | 138 ++++++++++++++++++++++++ >>> tools/objtool/objtool.c | 1 + >>> tools/objtool/weak.c | 5 + >>> 11 files changed, 247 insertions(+), 3 deletions(-) >>> create mode 100644 tools/objtool/builtin-mcount.c >>> create mode 100644 tools/objtool/mcount.c >>> >>> diff --git a/Makefile b/Makefile >>> index 55a30ca69350..316f7d08b30a 100644 >>> --- a/Makefile >>> +++ b/Makefile >>> @@ -846,7 +846,9 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_CC >>> endif >>> endif >>> ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL >>> + ifdef CONFIG_HAVE_NOP_MCOUNT >>> CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT >>> + endif >>> endif >>> ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT >>> ifdef CONFIG_HAVE_C_RECORDMCOUNT >>> @@ -1303,6 +1305,10 @@ ifdef CONFIG_STACK_VALIDATION >>> prepare: tools/objtool >>> endif >>> +ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL >>> +prepare: tools/objtool >>> +endif >> >> I don't think that will work for powerpc. >> >> See arch/powerpc/Makefile >> >> powerpc builds the VDSO under prepare: , and powerpc has >> CONFIG_HAVE_GENERIC_VDSO so there are some C files in that step that >> seem to use objtool, allthough that looks odd to me. Must be something >> to fix somewhere. >> >> powerpc64-linux-gcc >> -Wp,-MMD,arch/powerpc/kernel/vdso/.vgettimeofday-64.o.d -nostdinc >> -I./arch/powerpc/include -I./arch/powerpc/include/generated >> -I./include -I./arch/powerpc/include/uapi >> -I./arch/powerpc/include/generated/uapi -I./include/uapi >> -I./include/generated/uapi -include ./include/linux/compiler-version.h >> -include ./include/linux/kconfig.h -include >> ./include/linux/compiler_types.h -D__KERNEL__ -I ./arch/powerpc >> -DHAVE_AS_ATHIGH=1 -fmacro-prefix-map=./= -Wall -Wundef >> -Werror=strict-prototypes -Wno-trigraphs -fno-strict-aliasing >> -fno-common -fshort-wchar -fno-PIE >> -Werror=implicit-function-declaration -Werror=implicit-int >> -Werror=return-type -Wno-format-security -std=gnu89 -mbig-endian -m64 >> -msoft-float -pipe -mtraceback=no -mabi=elfv1 -mcall-aixdesc >> -mcmodel=medium -mno-pointers-to-nested-functions -mtune=power7 >> -mcpu=power5 -mno-altivec -mno-vsx -fno-asynchronous-unwind-tables >> -mno-string -Wa,-maltivec -Wa,-mpower4 -Wa,-many -mabi=elfv1 >> -mcall-aixdesc -mbig-endian -mstack-protector-guard=tls >> -mstack-protector-guard-reg=r13 -fno-delete-null-pointer-checks >> -Wno-frame-address -Wno-format-truncation -Wno-format-overflow >> -Wno-address-of-packed-member -O2 -fno-allow-store-data-races >> -Wframe-larger-than=2048 -fstack-protector-strong >> -Wimplicit-fallthrough=5 -Wno-main -Wno-unused-but-set-variable >> -Wno-unused-const-variable -fno-stack-clash-protection >> -Wdeclaration-after-statement -Wvla -Wno-pointer-sign >> -Wcast-function-type -Wno-stringop-truncation -Wno-zero-length-bounds >> -Wno-array-bounds -Wno-stringop-overflow -Wno-restrict >> -Wno-maybe-uninitialized -Wno-alloc-size-larger-than >> -fno-strict-overflow -fno-stack-check -fconserve-stack >> -Werror=date-time -Werror=incompatible-pointer-types >> -Werror=designated-init -Wno-packed-not-aligned >> -mstack-protector-guard-offset=3200 -shared -fno-common -fno-builtin >> -nostdlib -Wl,--hash-style=both -include >> /home/chleroy/linux-powerpc/lib/vdso/gettimeofday.c >> -fno-stack-protector -DDISABLE_BRANCH_PROFILING -ffreestanding >> -fasynchronous-unwind-tables -ffixed-r30 >> -DKBUILD_MODFILE='"arch/powerpc/kernel/vdso/vgettimeofday-64"' >> -DKBUILD_BASENAME='"vgettimeofday_64"' >> -DKBUILD_MODNAME='"vgettimeofday_64"' >> -D__KBUILD_MODNAME=kmod_vgettimeofday_64 -c -o >> arch/powerpc/kernel/vdso/vgettimeofday-64.o >> arch/powerpc/kernel/vdso/vgettimeofday.c ; ./tools/objtool/objtool >> mcount arch/powerpc/kernel/vdso/vgettimeofday-64.o > > We don't enable ftrace for vdso, so I suspect objtool run above will be > a no-op. This needs to be confirmed, of course. >
I just checked without the series: recordmcount isn't run for VDSO, so objtool shouldn't be run either when the series is applied. Christophe
