| Message ID | 20240724210515.473004-3-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 mremap manual entry: > > 1. Change mremap to variadic. > 2. Document MREMAP_FIXED and MREMAP_DONTUNMAP. > > Signed-off-by: H.J. Lu <hjl.tools@gmail.com> LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > manual/llio.texi | 42 +++++++++++++++++++++++++++++++++++------- > 1 file changed, 35 insertions(+), 7 deletions(-) > > diff --git a/manual/llio.texi b/manual/llio.texi > index 6f0a48609b..ea84196abd 100644 > --- a/manual/llio.texi > +++ b/manual/llio.texi > @@ -1892,7 +1892,7 @@ There is no existing mapping in at least part of the given region. > > @end deftypefun > > -@deftypefun {void *} mremap (void *@var{address}, size_t @var{length}, size_t @var{new_length}, int @var{flag}) > +@deftypefun {void *} mremap (void *@var{address}, size_t @var{length}, size_t @var{new_length}, int @var{flag}, ... /* void *@var{new_address} */) > @standards{GNU, sys/mman.h} > @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} > > @@ -1901,12 +1901,40 @@ area. @var{address} and @var{length} must cover a region entirely mapped > in the same @code{mmap} statement. A new mapping with the same > characteristics will be returned with the length @var{new_length}. > > -One option is possible, @code{MREMAP_MAYMOVE}. If it is given in > -@var{flags}, the system may remove the existing mapping and create a new > -one of the desired length in another location. > +Possible flags are > > -The address of the resulting mapping is returned, or @math{-1}. Possible > -error codes include: > +@table @code > + > +@item MREMAP_MAYMOVE > +If it is given in @var{flags}, the system may remove the existing mapping > +and create a new one of the desired length in another location. > + > +@item MREMAP_FIXED > +If it is given in @var{flags}, @code{mremap} accepts a fifth argument, > +@code{void *new_address}, which specifies a page-aligned address to > +which the mapping must be moved. Any previous mapping at the address > +range specified by @var{new_address} and @var{new_size} is unmapped. > + > +@code{MREMAP_FIXED} must be used together with @code{MREMAP_MAYMOVE}. > + > +@item MREMAP_DONTUNMAP > +If it is given in @var{flags}, @code{mremap} accepts a fifth argument, > +@code{void *new_address}, which specifies a page-aligned address. Any > +previous mapping at the address range specified by @var{new_address} and > +@var{new_size} is unmapped. If @var{new_address} is @code{NULL}, the > +kernel chooses the page-aligned address at which to create the mapping. > +Otherwise, the kernel takes it as a hint about where to place the mapping. > +The mapping at the address range specified by @var{old_address} and > +@var{old_size} isn't unmapped. > + > +@code{MREMAP_DONTUNMAP} must be used together with @code{MREMAP_MAYMOVE}. > +@var{old_size} must be the same as @var{new_size}. This flag bit is > +Linux-specific. > + > +@end table > + > +The address of the resulting mapping is returned, or @code{MAP_FAILED}. > +Possible error codes include: > > @table @code > > @@ -1915,7 +1943,7 @@ There is no existing mapping in at least part of the original region, or > the region covers two or more distinct mappings. > > @item EINVAL > -The address given is misaligned or inappropriate. > +Any arguments are inappropriate, including unknown @var{flags} values. > > @item EAGAIN > The region has pages locked, and if extended it would exceed the
diff --git a/manual/llio.texi b/manual/llio.texi index 6f0a48609b..ea84196abd 100644 --- a/manual/llio.texi +++ b/manual/llio.texi @@ -1892,7 +1892,7 @@ There is no existing mapping in at least part of the given region. @end deftypefun -@deftypefun {void *} mremap (void *@var{address}, size_t @var{length}, size_t @var{new_length}, int @var{flag}) +@deftypefun {void *} mremap (void *@var{address}, size_t @var{length}, size_t @var{new_length}, int @var{flag}, ... /* void *@var{new_address} */) @standards{GNU, sys/mman.h} @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} @@ -1901,12 +1901,40 @@ area. @var{address} and @var{length} must cover a region entirely mapped in the same @code{mmap} statement. A new mapping with the same characteristics will be returned with the length @var{new_length}. -One option is possible, @code{MREMAP_MAYMOVE}. If it is given in -@var{flags}, the system may remove the existing mapping and create a new -one of the desired length in another location. +Possible flags are -The address of the resulting mapping is returned, or @math{-1}. Possible -error codes include: +@table @code + +@item MREMAP_MAYMOVE +If it is given in @var{flags}, the system may remove the existing mapping +and create a new one of the desired length in another location. + +@item MREMAP_FIXED +If it is given in @var{flags}, @code{mremap} accepts a fifth argument, +@code{void *new_address}, which specifies a page-aligned address to +which the mapping must be moved. Any previous mapping at the address +range specified by @var{new_address} and @var{new_size} is unmapped. + +@code{MREMAP_FIXED} must be used together with @code{MREMAP_MAYMOVE}. + +@item MREMAP_DONTUNMAP +If it is given in @var{flags}, @code{mremap} accepts a fifth argument, +@code{void *new_address}, which specifies a page-aligned address. Any +previous mapping at the address range specified by @var{new_address} and +@var{new_size} is unmapped. If @var{new_address} is @code{NULL}, the +kernel chooses the page-aligned address at which to create the mapping. +Otherwise, the kernel takes it as a hint about where to place the mapping. +The mapping at the address range specified by @var{old_address} and +@var{old_size} isn't unmapped. + +@code{MREMAP_DONTUNMAP} must be used together with @code{MREMAP_MAYMOVE}. +@var{old_size} must be the same as @var{new_size}. This flag bit is +Linux-specific. + +@end table + +The address of the resulting mapping is returned, or @code{MAP_FAILED}. +Possible error codes include: @table @code @@ -1915,7 +1943,7 @@ There is no existing mapping in at least part of the original region, or the region covers two or more distinct mappings. @item EINVAL -The address given is misaligned or inappropriate. +Any arguments are inappropriate, including unknown @var{flags} values. @item EAGAIN The region has pages locked, and if extended it would exceed the
Update mremap manual entry: 1. Change mremap to variadic. 2. Document MREMAP_FIXED and MREMAP_DONTUNMAP. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> --- manual/llio.texi | 42 +++++++++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 7 deletions(-)