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util/osdep: Avoid madvise proto on modern Solaris

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On older Solaris releases (before Solaris 11), we didn't get a
prototype for madvise, and so util/osdep.c provides its own prototype.
Some time between the public Solaris 11.4 release and Solaris 11.4.42
CBE, we started getting an madvise prototype that looks like this:

    extern int madvise(void *, size_t, int);

which conflicts with the prototype in util/osdeps.c. Instead of always
declaring this prototype, check if we're missing the madvise()
prototype, and only declare it ourselves if the prototype is missing.
Move the prototype to include/qemu/osdep.h, the normal place to handle
platform-specific header quirks.

The 'missing_madvise_proto' meson check contains an obviously wrong
prototype for madvise. So if that code compiles and links, we must be
missing the actual prototype for madvise.

Signed-off-by: Andrew Deason <adeason@sinenomine.net>
Message-id: 20220316035227.3702-2-adeason@sinenomine.net
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Andrew Deason 2022-03-15 22:52:25 -05:00 committed by Peter Maydell
parent eb7a38ba66
commit 8900c204df
3 changed files with 29 additions and 5 deletions
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8
include/qemu/osdep.h
View File

@ -400,6 +400,14 @@ void qemu_anon_ram_free(void *ptr, size_t size);
#define SIGIO SIGPOLL
#endif
#ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE
/*
* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion
* about Solaris missing the madvise() prototype.
*/
extern int madvise(char *, size_t, int);
#endif
#if defined(CONFIG_LINUX)
#ifndef BUS_MCEERR_AR
#define BUS_MCEERR_AR 4

23
meson.build
View File

@ -1715,11 +1715,30 @@ config_host_data.set('CONFIG_FDATASYNC', cc.links(gnu_source_prefix + '''
#error Not supported
#endif
}'''))
config_host_data.set('CONFIG_MADVISE', cc.links(gnu_source_prefix + '''
has_madvise = cc.links(gnu_source_prefix + '''
#include <sys/types.h>
#include <sys/mman.h>
#include <stddef.h>
int main(void) { return madvise(NULL, 0, MADV_DONTNEED); }'''))
int main(void) { return madvise(NULL, 0, MADV_DONTNEED); }''')
missing_madvise_proto = false
if has_madvise
# Some platforms (illumos and Solaris before Solaris 11) provide madvise()
# but forget to prototype it. In this case, has_madvise will be true (the
# test program links despite a compile warning). To detect the
# missing-prototype case, we try again with a definitely-bogus prototype.
# This will only compile if the system headers don't provide the prototype;
# otherwise the conflicting prototypes will cause a compiler error.
missing_madvise_proto = cc.links(gnu_source_prefix + '''
#include <sys/types.h>
#include <sys/mman.h>
#include <stddef.h>
extern int madvise(int);
int main(void) { return madvise(0); }''')
endif
config_host_data.set('CONFIG_MADVISE', has_madvise)
config_host_data.set('HAVE_MADVISE_WITHOUT_PROTOTYPE', missing_madvise_proto)
config_host_data.set('CONFIG_MEMFD', cc.links(gnu_source_prefix + '''
#include <sys/mman.h>
int main(void) { return memfd_create("foo", MFD_ALLOW_SEALING); }'''))

3
util/osdep.c
View File

@ -28,9 +28,6 @@
#ifdef CONFIG_SOLARIS
#include <sys/statvfs.h>
/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
discussion about Solaris header problems */
extern int madvise(char *, size_t, int);
#endif
#include "qemu-common.h"