| Message ID | cover.1727624528.git.fweimer@redhat.com |
|---|---|
| Headers | show |
| Series | Teach glibc about possible page sizes and handle gaps in ld.so | expand |
On Sun, Sep 29, 2024 at 11:47 PM Florian Weimer <fweimer@redhat.com> wrote: > > This series is another attempt to fix bug 31943. If the binutils RELRO > bug is fixed, we still run into a conceptual issue with LOAD segment > gaps if the system supports multiple page sizes (or at least, if ld uses > a larger page size than required on Linux, as it happens on some > targets). To avoid the overhead and loss of test coverage by accepting > gaps everywhere, this series teaches glibc the possible range of page > sizes for each supported architecture. > > Information regarding possible page sizes is useful to application > programmers, so this is exposed in a new <sys/pagesize.h> installed > header. It is just too tempting to use this to optimize getpagesize > etc., so the series contains some commits for that as well. No ABI > changes necessary. > > There is a new build failure on loongarch, apparently unrelated, and > reported as GCC PR116887. > > Thanks, > Florian > > Florian Weimer (29): > elf: Add tests to verify that l_contiguous reflects reality > Prepare for the addition of the <sys/pagesize.h> header > aarch64: Add <bits/pagesize.h> > alpha: Add <bits/pagesize.h> > arc: Add <bits/pagesize.h> > arm: Add <bits/pagesize.h> > csky: Add <bits/pagesize.h> > hppa: Add <bits/pagesize.h> > loongarch: Add <bits/pagesize.h> > m68k: Add <bits/pagesize.h> > microblaze: Add <bits/pagesize.h> > mips: Add <bits/pagesize.h> > nios2: Add <bits/pagesize.h> > or1k: Add <bits/pagesize.h> > powerpc: Add <bits/pagesize.h> > riscv: Add <bits/pagesize.h> > s390: Add <bits/pagesize.h> > sh: Add <bits/pagesize.h> > sparc: Add <bits/pagesize.h> > x86: Add <bits/pagesize.h> > misc: Add tst-getpagesize > elf: Extract rtld_setup_phdr function from dl_main > configure: Add --with-ld-relro-load-gaps configure option and test > elf: Handle ld.so with LOAD segment gaps in _dl_find_object (bug > 31943) > Install the <sys/pagesize.h> header file > Linux: Optimize getpagesize using <sys/pagesize.h> > malloc: Use volatile as compiler barrier in tst-memalign, tst-valloc > posix: Use <support/next_to_fault.h> in tst-fnmatch3 > Optimize various ways to obtain the page size using <bits/pagesize.h> Should pagesize.h files have a copyright notice? How many pagesize.h files are identical? Should the most common ones be shared? > INSTALL | 12 +++ > NEWS | 5 + > bits/pagesize.h | 10 ++ > bits/shm.h | 9 ++ > config.h.in | 3 + > configure | 39 ++++++++ > configure.ac | 20 ++++ > elf/Makefile | 31 ++++++ > elf/dl-find_object.c | 78 +++++++++------ > elf/rtld.c | 84 +++++++++++----- > elf/tst-link-map-contiguous-ldso.c | 43 ++++++++ > elf/tst-link-map-contiguous-libc.c | 57 +++++++++++ > elf/tst-link-map-contiguous-main.c | 45 +++++++++ > elf/tst-program-headers.py | 137 ++++++++++++++++++++++++++ > include/sys/pagesize.h | 1 + > malloc/tst-memalign.c | 17 ++-- > malloc/tst-valloc.c | 17 ++-- > manual/install.texi | 12 +++ > manual/resource.texi | 31 ++++++ > misc/Makefile | 3 + > misc/sys/pagesize.h | 32 ++++++ > misc/tst-getpagesize.c | 65 ++++++++++++ > posix/tst-fnmatch3.c | 23 ++--- > posix/unistd.h | 21 ++++ > sysdeps/aarch64/bits/pagesize.h | 2 + > sysdeps/alpha/bits/pagesize.h | 2 + > sysdeps/arc/bits/pagesize.h | 2 + > sysdeps/arm/bits/pagesize.h | 2 + > sysdeps/csky/bits/pagesize.h | 2 + > sysdeps/hppa/bits/pagesize.h | 2 + > sysdeps/loongarch/bits/pagesize.h | 2 + > sysdeps/m68k/bits/pagesize.h | 2 + > sysdeps/m68k/coldfire/bits/pagesize.h | 2 + > sysdeps/microblaze/bits/pagesize.h | 2 + > sysdeps/mips/bits/pagesize.h | 2 + > sysdeps/nios2/bits/pagesize.h | 2 + > sysdeps/or1k/bits/pagesize.h | 2 + > sysdeps/powerpc/bits/pagesize.h | 2 + > sysdeps/riscv/bits/pagesize.h | 2 + > sysdeps/s390/bits/pagesize.h | 2 + > sysdeps/sh/bits/pagesize.h | 2 + > sysdeps/sparc/sparc32/bits/pagesize.h | 2 + > sysdeps/sparc/sparc64/bits/pagesize.h | 2 + > sysdeps/unix/sysv/linux/arc/Makefile | 5 + > sysdeps/unix/sysv/linux/arm/Makefile | 3 + > sysdeps/unix/sysv/linux/getpagesize.c | 5 + > sysdeps/x86/bits/pagesize.h | 2 + > 47 files changed, 758 insertions(+), 90 deletions(-) > create mode 100644 bits/pagesize.h > create mode 100644 elf/tst-link-map-contiguous-ldso.c > create mode 100644 elf/tst-link-map-contiguous-libc.c > create mode 100644 elf/tst-link-map-contiguous-main.c > create mode 100644 elf/tst-program-headers.py > create mode 100644 include/sys/pagesize.h > create mode 100644 misc/sys/pagesize.h > create mode 100644 misc/tst-getpagesize.c > create mode 100644 sysdeps/aarch64/bits/pagesize.h > create mode 100644 sysdeps/alpha/bits/pagesize.h > create mode 100644 sysdeps/arc/bits/pagesize.h > create mode 100644 sysdeps/arm/bits/pagesize.h > create mode 100644 sysdeps/csky/bits/pagesize.h > create mode 100644 sysdeps/hppa/bits/pagesize.h > create mode 100644 sysdeps/loongarch/bits/pagesize.h > create mode 100644 sysdeps/m68k/bits/pagesize.h > create mode 100644 sysdeps/m68k/coldfire/bits/pagesize.h > create mode 100644 sysdeps/microblaze/bits/pagesize.h > create mode 100644 sysdeps/mips/bits/pagesize.h > create mode 100644 sysdeps/nios2/bits/pagesize.h > create mode 100644 sysdeps/or1k/bits/pagesize.h > create mode 100644 sysdeps/powerpc/bits/pagesize.h > create mode 100644 sysdeps/riscv/bits/pagesize.h > create mode 100644 sysdeps/s390/bits/pagesize.h > create mode 100644 sysdeps/sh/bits/pagesize.h > create mode 100644 sysdeps/sparc/sparc32/bits/pagesize.h > create mode 100644 sysdeps/sparc/sparc64/bits/pagesize.h > create mode 100644 sysdeps/x86/bits/pagesize.h > > > base-commit: 6948ee4edf0c57c556f8d5f394d9191216d05780 > -- > 2.46.2 > H.J.
* H. J. Lu: >> Optimize various ways to obtain the page size using <bits/pagesize.h> > > Should pagesize.h files have a copyright notice? How many pagesize.h files > are identical? Should the most common ones be shared? There's already a copyright notice in <sys/pagesize.h>. Other very short bits/ headers do not have copyright notices, either, so I didn't think one was necessary here. Sharing files is hard. We could set the default at 4 KiB pages (only), which would avoid the need for some files, but we then lose the reminder to new port authors that they need to think about future page size ranges, especially if there are no test failures because the initial test system has 4 KiB pages. Thanks, Florian
This series is another attempt to fix bug 31943. If the binutils RELRO bug is fixed, we still run into a conceptual issue with LOAD segment gaps if the system supports multiple page sizes (or at least, if ld uses a larger page size than required on Linux, as it happens on some targets). To avoid the overhead and loss of test coverage by accepting gaps everywhere, this series teaches glibc the possible range of page sizes for each supported architecture. Information regarding possible page sizes is useful to application programmers, so this is exposed in a new <sys/pagesize.h> installed header. It is just too tempting to use this to optimize getpagesize etc., so the series contains some commits for that as well. No ABI changes necessary. There is a new build failure on loongarch, apparently unrelated, and reported as GCC PR116887. Thanks, Florian Florian Weimer (29): elf: Add tests to verify that l_contiguous reflects reality Prepare for the addition of the <sys/pagesize.h> header aarch64: Add <bits/pagesize.h> alpha: Add <bits/pagesize.h> arc: Add <bits/pagesize.h> arm: Add <bits/pagesize.h> csky: Add <bits/pagesize.h> hppa: Add <bits/pagesize.h> loongarch: Add <bits/pagesize.h> m68k: Add <bits/pagesize.h> microblaze: Add <bits/pagesize.h> mips: Add <bits/pagesize.h> nios2: Add <bits/pagesize.h> or1k: Add <bits/pagesize.h> powerpc: Add <bits/pagesize.h> riscv: Add <bits/pagesize.h> s390: Add <bits/pagesize.h> sh: Add <bits/pagesize.h> sparc: Add <bits/pagesize.h> x86: Add <bits/pagesize.h> misc: Add tst-getpagesize elf: Extract rtld_setup_phdr function from dl_main configure: Add --with-ld-relro-load-gaps configure option and test elf: Handle ld.so with LOAD segment gaps in _dl_find_object (bug 31943) Install the <sys/pagesize.h> header file Linux: Optimize getpagesize using <sys/pagesize.h> malloc: Use volatile as compiler barrier in tst-memalign, tst-valloc posix: Use <support/next_to_fault.h> in tst-fnmatch3 Optimize various ways to obtain the page size using <bits/pagesize.h> INSTALL | 12 +++ NEWS | 5 + bits/pagesize.h | 10 ++ bits/shm.h | 9 ++ config.h.in | 3 + configure | 39 ++++++++ configure.ac | 20 ++++ elf/Makefile | 31 ++++++ elf/dl-find_object.c | 78 +++++++++------ elf/rtld.c | 84 +++++++++++----- elf/tst-link-map-contiguous-ldso.c | 43 ++++++++ elf/tst-link-map-contiguous-libc.c | 57 +++++++++++ elf/tst-link-map-contiguous-main.c | 45 +++++++++ elf/tst-program-headers.py | 137 ++++++++++++++++++++++++++ include/sys/pagesize.h | 1 + malloc/tst-memalign.c | 17 ++-- malloc/tst-valloc.c | 17 ++-- manual/install.texi | 12 +++ manual/resource.texi | 31 ++++++ misc/Makefile | 3 + misc/sys/pagesize.h | 32 ++++++ misc/tst-getpagesize.c | 65 ++++++++++++ posix/tst-fnmatch3.c | 23 ++--- posix/unistd.h | 21 ++++ sysdeps/aarch64/bits/pagesize.h | 2 + sysdeps/alpha/bits/pagesize.h | 2 + sysdeps/arc/bits/pagesize.h | 2 + sysdeps/arm/bits/pagesize.h | 2 + sysdeps/csky/bits/pagesize.h | 2 + sysdeps/hppa/bits/pagesize.h | 2 + sysdeps/loongarch/bits/pagesize.h | 2 + sysdeps/m68k/bits/pagesize.h | 2 + sysdeps/m68k/coldfire/bits/pagesize.h | 2 + sysdeps/microblaze/bits/pagesize.h | 2 + sysdeps/mips/bits/pagesize.h | 2 + sysdeps/nios2/bits/pagesize.h | 2 + sysdeps/or1k/bits/pagesize.h | 2 + sysdeps/powerpc/bits/pagesize.h | 2 + sysdeps/riscv/bits/pagesize.h | 2 + sysdeps/s390/bits/pagesize.h | 2 + sysdeps/sh/bits/pagesize.h | 2 + sysdeps/sparc/sparc32/bits/pagesize.h | 2 + sysdeps/sparc/sparc64/bits/pagesize.h | 2 + sysdeps/unix/sysv/linux/arc/Makefile | 5 + sysdeps/unix/sysv/linux/arm/Makefile | 3 + sysdeps/unix/sysv/linux/getpagesize.c | 5 + sysdeps/x86/bits/pagesize.h | 2 + 47 files changed, 758 insertions(+), 90 deletions(-) create mode 100644 bits/pagesize.h create mode 100644 elf/tst-link-map-contiguous-ldso.c create mode 100644 elf/tst-link-map-contiguous-libc.c create mode 100644 elf/tst-link-map-contiguous-main.c create mode 100644 elf/tst-program-headers.py create mode 100644 include/sys/pagesize.h create mode 100644 misc/sys/pagesize.h create mode 100644 misc/tst-getpagesize.c create mode 100644 sysdeps/aarch64/bits/pagesize.h create mode 100644 sysdeps/alpha/bits/pagesize.h create mode 100644 sysdeps/arc/bits/pagesize.h create mode 100644 sysdeps/arm/bits/pagesize.h create mode 100644 sysdeps/csky/bits/pagesize.h create mode 100644 sysdeps/hppa/bits/pagesize.h create mode 100644 sysdeps/loongarch/bits/pagesize.h create mode 100644 sysdeps/m68k/bits/pagesize.h create mode 100644 sysdeps/m68k/coldfire/bits/pagesize.h create mode 100644 sysdeps/microblaze/bits/pagesize.h create mode 100644 sysdeps/mips/bits/pagesize.h create mode 100644 sysdeps/nios2/bits/pagesize.h create mode 100644 sysdeps/or1k/bits/pagesize.h create mode 100644 sysdeps/powerpc/bits/pagesize.h create mode 100644 sysdeps/riscv/bits/pagesize.h create mode 100644 sysdeps/s390/bits/pagesize.h create mode 100644 sysdeps/sh/bits/pagesize.h create mode 100644 sysdeps/sparc/sparc32/bits/pagesize.h create mode 100644 sysdeps/sparc/sparc64/bits/pagesize.h create mode 100644 sysdeps/x86/bits/pagesize.h base-commit: 6948ee4edf0c57c556f8d5f394d9191216d05780