Re: [PATCH 01/10] Documentation: raise minimum supported version of GCC to 5.1
From: Nathan Chancellor <nathan@kernel.org>
Date: 2021-09-10 23:56:02
Also in:
lkml
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/ (local) Link: https://lore.kernel.org/lkml/CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com/ (local) Link: https://github.com/ClangBuiltLinux/linux/issues/1438 Reported-by: Stephen Rothwell <redacted> 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>
quoted hunk ↗ jump to hunk
--- 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 -vdiff --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