| Message ID | 20210325223807.2423265-1-nathan@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | Fix CONFIG_FUNCTION_TRACER with clang | expand |
On Thu, Mar 25, 2021 at 11:38 PM Nathan Chancellor <nathan@kernel.org> wrote: > > Hi all, > > This series fixes function tracing with clang. > > Patch 1 adjusts the mcount regex in scripts/recordmcount.pl to handle > the presence of PLT relocations, which happen with clang. Without this, > the mcount_loc section will not be created properly. > > Patch 2 adds a workaround for clang less than 13.0.0 in relation to the > mcount symbol name, which was "mcount" rather than "_mcount". This was > written as a separate patch so that it can be reverted when the minimum > clang version is bumped to clang 13.0.0. > > Patch 3 avoids a build error when -fpatchable-function-entry is not > available, which is the case with clang less than 13.0.0. This will make > dynamic ftrace unavailable but all of the other function tracing should > work due to the prescence of the previous patch. > > I am hoping this series can go in as fixes for 5.12, due to patch 3, but > if not, they can always be backported (patches 1 and 2 are already > marked for stable). > > This series has been build tested with gcc-8 through gcc-10 and clang-11 > through clang-13 with defconfig and nommu_virt_defconfig plus > CONFIG_FTRACE=y and CONFIG_FUNCTION_TRACER=y then boot tested under > QEMU. > > Cheers, > Nathan > > Nathan Chancellor (3): > scripts/recordmcount.pl: Fix RISC-V regex for clang > riscv: Workaround mcount name prior to clang-13 > riscv: Select HAVE_DYNAMIC_FTRACE when -fpatchable-function-entry is > available > Does this only fixes stuff for clang + riscv? If so, please put a label "riscv" also in the cover-letter. - Sedat - > arch/riscv/Kconfig | 2 +- > arch/riscv/include/asm/ftrace.h | 14 ++++++++++++-- > arch/riscv/kernel/mcount.S | 10 +++++----- > scripts/recordmcount.pl | 2 +- > 4 files changed, 19 insertions(+), 9 deletions(-) > > -- > 2.31.0 > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20210325223807.2423265-1-nathan%40kernel.org.
On Fri, Mar 26, 2021 at 09:37:55AM +0100, Sedat Dilek wrote: > On Thu, Mar 25, 2021 at 11:38 PM Nathan Chancellor <nathan@kernel.org> wrote: > > > > Hi all, > > > > This series fixes function tracing with clang. > > > > Patch 1 adjusts the mcount regex in scripts/recordmcount.pl to handle > > the presence of PLT relocations, which happen with clang. Without this, > > the mcount_loc section will not be created properly. > > > > Patch 2 adds a workaround for clang less than 13.0.0 in relation to the > > mcount symbol name, which was "mcount" rather than "_mcount". This was > > written as a separate patch so that it can be reverted when the minimum > > clang version is bumped to clang 13.0.0. > > > > Patch 3 avoids a build error when -fpatchable-function-entry is not > > available, which is the case with clang less than 13.0.0. This will make > > dynamic ftrace unavailable but all of the other function tracing should > > work due to the prescence of the previous patch. > > > > I am hoping this series can go in as fixes for 5.12, due to patch 3, but > > if not, they can always be backported (patches 1 and 2 are already > > marked for stable). > > > > This series has been build tested with gcc-8 through gcc-10 and clang-11 > > through clang-13 with defconfig and nommu_virt_defconfig plus > > CONFIG_FTRACE=y and CONFIG_FUNCTION_TRACER=y then boot tested under > > QEMU. > > > > Cheers, > > Nathan > > > > Nathan Chancellor (3): > > scripts/recordmcount.pl: Fix RISC-V regex for clang > > riscv: Workaround mcount name prior to clang-13 > > riscv: Select HAVE_DYNAMIC_FTRACE when -fpatchable-function-entry is > > available > > > > Does this only fixes stuff for clang + riscv? Yes. > If so, please put a label "riscv" also in the cover-letter. Sure, my apologies for not doing that in the first place, I must have been in a rush with the cover letter. In my defense, I think the titles of my commit messages and the diffstat below make that obvious without the tag :) Cheers, Nathan > - Sedat - > > > arch/riscv/Kconfig | 2 +- > > arch/riscv/include/asm/ftrace.h | 14 ++++++++++++-- > > arch/riscv/kernel/mcount.S | 10 +++++----- > > scripts/recordmcount.pl | 2 +- > > 4 files changed, 19 insertions(+), 9 deletions(-) > > > > -- > > 2.31.0 > >
On Fri, Mar 26, 2021 at 2:07 PM Nathan Chancellor <nathan@kernel.org> wrote: > > On Fri, Mar 26, 2021 at 09:37:55AM +0100, Sedat Dilek wrote: > > On Thu, Mar 25, 2021 at 11:38 PM Nathan Chancellor <nathan@kernel.org> wrote: > > > > > > Hi all, > > > > > > This series fixes function tracing with clang. > > > > > > Patch 1 adjusts the mcount regex in scripts/recordmcount.pl to handle > > > the presence of PLT relocations, which happen with clang. Without this, > > > the mcount_loc section will not be created properly. > > > > > > Patch 2 adds a workaround for clang less than 13.0.0 in relation to the > > > mcount symbol name, which was "mcount" rather than "_mcount". This was > > > written as a separate patch so that it can be reverted when the minimum > > > clang version is bumped to clang 13.0.0. > > > > > > Patch 3 avoids a build error when -fpatchable-function-entry is not > > > available, which is the case with clang less than 13.0.0. This will make > > > dynamic ftrace unavailable but all of the other function tracing should > > > work due to the prescence of the previous patch. > > > > > > I am hoping this series can go in as fixes for 5.12, due to patch 3, but > > > if not, they can always be backported (patches 1 and 2 are already > > > marked for stable). > > > > > > This series has been build tested with gcc-8 through gcc-10 and clang-11 > > > through clang-13 with defconfig and nommu_virt_defconfig plus > > > CONFIG_FTRACE=y and CONFIG_FUNCTION_TRACER=y then boot tested under > > > QEMU. > > > > > > Cheers, > > > Nathan > > > > > > Nathan Chancellor (3): > > > scripts/recordmcount.pl: Fix RISC-V regex for clang > > > riscv: Workaround mcount name prior to clang-13 > > > riscv: Select HAVE_DYNAMIC_FTRACE when -fpatchable-function-entry is > > > available > > > > > > > Does this only fixes stuff for clang + riscv? > > Yes. > > > If so, please put a label "riscv" also in the cover-letter. > > Sure, my apologies for not doing that in the first place, I must have > been in a rush with the cover letter. > > In my defense, I think the titles of my commit messages and the diffstat > below make that obvious without the tag :) > No need for any apologies. I was fooled as you sent two triple-patchset nearly simultaneously. This riscv patchset here was not of interest to me. - Sedat - > > > - Sedat - > > > > > arch/riscv/Kconfig | 2 +- > > > arch/riscv/include/asm/ftrace.h | 14 ++++++++++++-- > > > arch/riscv/kernel/mcount.S | 10 +++++----- > > > scripts/recordmcount.pl | 2 +- > > > 4 files changed, 19 insertions(+), 9 deletions(-) > > > > > > -- > > > 2.31.0 > > >
On Thu, 25 Mar 2021 15:38:04 PDT (-0700), nathan@kernel.org wrote: > Hi all, > > This series fixes function tracing with clang. > > Patch 1 adjusts the mcount regex in scripts/recordmcount.pl to handle > the presence of PLT relocations, which happen with clang. Without this, > the mcount_loc section will not be created properly. > > Patch 2 adds a workaround for clang less than 13.0.0 in relation to the > mcount symbol name, which was "mcount" rather than "_mcount". This was > written as a separate patch so that it can be reverted when the minimum > clang version is bumped to clang 13.0.0. > > Patch 3 avoids a build error when -fpatchable-function-entry is not > available, which is the case with clang less than 13.0.0. This will make > dynamic ftrace unavailable but all of the other function tracing should > work due to the prescence of the previous patch. > > I am hoping this series can go in as fixes for 5.12, due to patch 3, but > if not, they can always be backported (patches 1 and 2 are already > marked for stable). > > This series has been build tested with gcc-8 through gcc-10 and clang-11 > through clang-13 with defconfig and nommu_virt_defconfig plus > CONFIG_FTRACE=y and CONFIG_FUNCTION_TRACER=y then boot tested under > QEMU. > > Cheers, > Nathan > > Nathan Chancellor (3): > scripts/recordmcount.pl: Fix RISC-V regex for clang > riscv: Workaround mcount name prior to clang-13 > riscv: Select HAVE_DYNAMIC_FTRACE when -fpatchable-function-entry is > available > > arch/riscv/Kconfig | 2 +- > arch/riscv/include/asm/ftrace.h | 14 ++++++++++++-- > arch/riscv/kernel/mcount.S | 10 +++++----- > scripts/recordmcount.pl | 2 +- > 4 files changed, 19 insertions(+), 9 deletions(-) Thanks, these are on for-next.
Hi all, This series fixes function tracing with clang. Patch 1 adjusts the mcount regex in scripts/recordmcount.pl to handle the presence of PLT relocations, which happen with clang. Without this, the mcount_loc section will not be created properly. Patch 2 adds a workaround for clang less than 13.0.0 in relation to the mcount symbol name, which was "mcount" rather than "_mcount". This was written as a separate patch so that it can be reverted when the minimum clang version is bumped to clang 13.0.0. Patch 3 avoids a build error when -fpatchable-function-entry is not available, which is the case with clang less than 13.0.0. This will make dynamic ftrace unavailable but all of the other function tracing should work due to the prescence of the previous patch. I am hoping this series can go in as fixes for 5.12, due to patch 3, but if not, they can always be backported (patches 1 and 2 are already marked for stable). This series has been build tested with gcc-8 through gcc-10 and clang-11 through clang-13 with defconfig and nommu_virt_defconfig plus CONFIG_FTRACE=y and CONFIG_FUNCTION_TRACER=y then boot tested under QEMU. Cheers, Nathan Nathan Chancellor (3): scripts/recordmcount.pl: Fix RISC-V regex for clang riscv: Workaround mcount name prior to clang-13 riscv: Select HAVE_DYNAMIC_FTRACE when -fpatchable-function-entry is available arch/riscv/Kconfig | 2 +- arch/riscv/include/asm/ftrace.h | 14 ++++++++++++-- arch/riscv/kernel/mcount.S | 10 +++++----- scripts/recordmcount.pl | 2 +- 4 files changed, 19 insertions(+), 9 deletions(-)