Messages in this thread | | | Subject | Re: [PATCH 01/10] Documentation: raise minimum supported version of GCC to 5.1 | From | Nathan Chancellor <> | Date | Fri, 10 Sep 2021 16:55:55 -0700 |
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On 9/10/2021 4:40 PM, Nick Desaulniers wrote: > commit fad7cd3310db ("nbd: add the check to prevent overflow in > __nbd_ioctl()") > > raised an issue from the fallback helpers added in > > commit f0907827a8a9 ("compiler.h: enable builtin overflow checkers and add fallback code") > > Specifically, the helpers for checking whether the results of a > multiplication overflowed (__unsigned_mul_overflow, > __signed_add_overflow) use the division operator when > !COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW. This is problematic for 64b > operands on 32b hosts.
"hosts" -> "targets" or "architectures"?
It might be worth putting the error that Stephen found here?
> Also, because the macro is type agnostic, it is very difficult to write > a similarly type generic macro that dispatches to one of: > * div64_s64 > * div64_u64 > * div_s64 > * div_u64 > > Raising the minimum supported versions allows us to remove all of the > fallback helpers for !COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW, instead > dispatching the compiler builtins. > > arm64 has already raised the minimum supported GCC version to 5.1, do > this for all targets now. See the link below for the previous > discussion. > > Link: https://lore.kernel.org/all/20210909182525.372ee687@canb.auug.org.au/ > Link: https://lore.kernel.org/lkml/CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com/ > Link: https://github.com/ClangBuiltLinux/linux/issues/1438 > Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> > Reported-by: Nathan Chancellor <nathan@kernel.org> > Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
> --- > Documentation/process/changes.rst | 2 +- > scripts/min-tool-version.sh | 8 +------- > 2 files changed, 2 insertions(+), 8 deletions(-) > > diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst > index d3a8557b66a1..e35ab74a0f80 100644 > --- a/Documentation/process/changes.rst > +++ b/Documentation/process/changes.rst > @@ -29,7 +29,7 @@ you probably needn't concern yourself with pcmciautils. > ====================== =============== ======================================== > Program Minimal version Command to check the version > ====================== =============== ======================================== > -GNU C 4.9 gcc --version > +GNU C 5.1 gcc --version > Clang/LLVM (optional) 10.0.1 clang --version > GNU make 3.81 make --version > binutils 2.23 ld -v > diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh > index 319f92104f56..4edc708baa63 100755 > --- a/scripts/min-tool-version.sh > +++ b/scripts/min-tool-version.sh > @@ -17,13 +17,7 @@ binutils) > echo 2.23.0 > ;; > gcc) > - # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293 > - # https://lore.kernel.org/r/20210107111841.GN1551@shell.armlinux.org.uk > - if [ "$SRCARCH" = arm64 ]; then > - echo 5.1.0 > - else > - echo 4.9.0 > - fi > + echo 5.1.0 > ;; > icc) > # temporary >
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