Hi Mark,
On Mon, 6 Jul 2026 16:47:43 -0700
Mark Geisert wrote:
> Currently madvise() and posix_madvise() are wired together as one
> function: the latter. But their error returns should be different.
> Make madvise a first-class export in cygwin.din; code a new madvise()
> that calls posix_madvise() and massages any error return.
>
> Reported-by: Christian Franke <[email protected]>
> Addresses: https://cygwin.com/pipermail/cygwin/2026-July/259872.html
> Signed-off-by: Mark Geisert <[email protected]>
> Fixes: 61522196c715 (* Merge in cygwin-64bit-branch.)
>
> ---
> winsup/cygwin/cygwin.din | 2 +-
> winsup/cygwin/include/cygwin/version.h | 3 ++-
> winsup/cygwin/mm/mmap.cc | 12 ++++++++++++
> 3 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/winsup/cygwin/cygwin.din b/winsup/cygwin/cygwin.din
> index 2e53bc819..937eacdaf 100644
> --- a/winsup/cygwin/cygwin.din
> +++ b/winsup/cygwin/cygwin.din
> @@ -951,7 +951,7 @@ lseek SIGFE
> lsetxattr SIGFE
> lstat SIGFE
> lutimes SIGFE
> -madvise = posix_madvise SIGFE
> +madvise SIGFE
> makecontext NOSIGFE
> mallinfo SIGFE
> malloc SIGFE
> diff --git a/winsup/cygwin/include/cygwin/version.h
> b/winsup/cygwin/include/cygwin/version.h
> index 71ac5282b..fc838e23e 100644
> --- a/winsup/cygwin/include/cygwin/version.h
> +++ b/winsup/cygwin/include/cygwin/version.h
> @@ -502,12 +502,13 @@ details. */
> 360: Add RLIMIT_NPROC.
> 361: Export _Fork.
> 362: Export C23 stdbit functions.
> + 363: Export madvise separately from posix_madvise.
>
> Note that we forgot to bump the api for ualarm, strtoll, strtoull,
> sigaltstack, sethostname. */
>
> #define CYGWIN_VERSION_API_MAJOR 0
> -#define CYGWIN_VERSION_API_MINOR 362
> +#define CYGWIN_VERSION_API_MINOR 363
>
> /* There is also a compatibity version number associated with the shared
> memory
> regions. It is incremented when incompatible changes are made to the
> shared
I don't think we should change CYGWIN_VERSION_API_MINOR value
because the API itself is not changed. This patch fixes a bug
in madvice() implementation.
> diff --git a/winsup/cygwin/mm/mmap.cc b/winsup/cygwin/mm/mmap.cc
> index 1416e4ddc..93db9e474 100644
> --- a/winsup/cygwin/mm/mmap.cc
> +++ b/winsup/cygwin/mm/mmap.cc
> @@ -1422,6 +1422,18 @@ munlock (const void *addr, size_t len)
> return ret;
> }
>
> +extern "C" int
> +madvise (void *addr, size_t len, int advice)
> +{
> + int ret = posix_madvise (addr, len, advice);
> + if (ret > 0)
> + {
> + set_errno (ret);
> + ret = -1;
> + }
> + return ret;
> +}
> +
> extern "C" int
> posix_madvise (void *addr, size_t len, int advice)
> {
> --
> 2.51.0
>
Patch itself LGTM. Thanks!
--
Takashi Yano <[email protected]>
