From 0be52c825176152ebe60ccd9f099b7722322c700 Mon Sep 17 00:00:00 2001 From: Santiago Gimeno Date: Mon, 7 Oct 2024 08:47:16 +0200 Subject: [PATCH] unix: workaround gcc bug on armv7 (#4564) Disable optimization on `uv__preadv_or_pwritev`. Fixes: https://github.com/libuv/libuv/issues/4532 Fixes: https://github.com/libuv/libuv/issues/4550 --- README.md | 4 ---- src/unix/fs.c | 10 ++++++---- 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/README.md b/README.md index 8afda75c..12c3061a 100644 --- a/README.md +++ b/README.md @@ -343,10 +343,6 @@ after the process terminates unless the event loop is closed. Use the `ipcrm` command to manually clear up System V resources. -## Known Issues - -- A possible arm-linux-gnueabihf-gcc bug causing, sometimes, incorrect generated code on `armv7` when calling `preadv()`: https://github.com/libuv/libuv/issues/4532. - ## Patches See the [guidelines for contributing][]. diff --git a/src/unix/fs.c b/src/unix/fs.c index d555491a..263d4bbc 100644 --- a/src/unix/fs.c +++ b/src/unix/fs.c @@ -461,7 +461,12 @@ static ssize_t uv__pwritev_emul(int fd, /* The function pointer cache is an uintptr_t because _Atomic void* * doesn't work on macos/ios/etc... + * Disable optimization on armv7 to work around the bug described in + * https://github.com/libuv/libuv/issues/4532 */ +#if defined(__arm__) && (__ARM_ARCH == 7) +__attribute__((optimize("O0"))) +#endif static ssize_t uv__preadv_or_pwritev(int fd, const struct iovec* bufs, size_t nbufs, @@ -482,10 +487,7 @@ static ssize_t uv__preadv_or_pwritev(int fd, atomic_store_explicit(cache, (uintptr_t) p, memory_order_relaxed); } - /* Use memcpy instead of `f = p` to work around a compiler bug, - * see https://github.com/libuv/libuv/issues/4532 - */ - memcpy(&f, &p, sizeof(p)); + f = p; return f(fd, bufs, nbufs, off); }