| Message ID | 20240724210515.473004-2-hjl.tools@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | linux: Update the mremap C implementation [BZ #31968] | expand |
On 24/07/24 18:05, H.J. Lu wrote: > Update the mremap C implementation to support the optional argument for > MREMAP_DONTUNMAP added in Linux 5.7 since it may not always be correct > to implement a variadic function as a non-variadic function on all Linux > targets. Return MAP_FAILED and set errno to EINVAL for unknown flag bits. > This fixes BZ #31968. > > Note: A test must be added when a new flag bit is introduced. > > Signed-off-by: H.J. Lu <hjl.tools@gmail.com> LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > sysdeps/unix/sysv/linux/mremap.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/sysdeps/unix/sysv/linux/mremap.c b/sysdeps/unix/sysv/linux/mremap.c > index 4f770799c4..1ada5c1f40 100644 > --- a/sysdeps/unix/sysv/linux/mremap.c > +++ b/sysdeps/unix/sysv/linux/mremap.c > @@ -20,6 +20,12 @@ > #include <sysdep.h> > #include <stdarg.h> > #include <stddef.h> > +#include <errno.h> > + > +#define MREMAP_KNOWN_BITS \ > + (MREMAP_MAYMOVE \ > + | MREMAP_FIXED \ > + | MREMAP_DONTUNMAP) > > void * > __mremap (void *addr, size_t old_len, size_t new_len, int flags, ...) > @@ -27,7 +33,13 @@ __mremap (void *addr, size_t old_len, size_t new_len, int flags, ...) > va_list va; > void *new_addr = NULL; > > - if (flags & MREMAP_FIXED) > + if (flags & ~(MREMAP_KNOWN_BITS)) > + { > + __set_errno (EINVAL); > + return MAP_FAILED; > + } > + > + if (flags & (MREMAP_FIXED | MREMAP_DONTUNMAP)) > { > va_start (va, flags); > new_addr = va_arg (va, void *);
diff --git a/sysdeps/unix/sysv/linux/mremap.c b/sysdeps/unix/sysv/linux/mremap.c index 4f770799c4..1ada5c1f40 100644 --- a/sysdeps/unix/sysv/linux/mremap.c +++ b/sysdeps/unix/sysv/linux/mremap.c @@ -20,6 +20,12 @@ #include <sysdep.h> #include <stdarg.h> #include <stddef.h> +#include <errno.h> + +#define MREMAP_KNOWN_BITS \ + (MREMAP_MAYMOVE \ + | MREMAP_FIXED \ + | MREMAP_DONTUNMAP) void * __mremap (void *addr, size_t old_len, size_t new_len, int flags, ...) @@ -27,7 +33,13 @@ __mremap (void *addr, size_t old_len, size_t new_len, int flags, ...) va_list va; void *new_addr = NULL; - if (flags & MREMAP_FIXED) + if (flags & ~(MREMAP_KNOWN_BITS)) + { + __set_errno (EINVAL); + return MAP_FAILED; + } + + if (flags & (MREMAP_FIXED | MREMAP_DONTUNMAP)) { va_start (va, flags); new_addr = va_arg (va, void *);
Update the mremap C implementation to support the optional argument for MREMAP_DONTUNMAP added in Linux 5.7 since it may not always be correct to implement a variadic function as a non-variadic function on all Linux targets. Return MAP_FAILED and set errno to EINVAL for unknown flag bits. This fixes BZ #31968. Note: A test must be added when a new flag bit is introduced. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> --- sysdeps/unix/sysv/linux/mremap.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)