linux-user: Use correct type for FIBMAP and FIGETBSZ emulation

[PATCH v2] linux-user: Use correct type for FIBMAP and FIGETBSZ emulation

Posted by Bastian Blank 2 weeks, 3 days ago

Both the FIBMAP and FIGETBSZ ioctl get "int *" (pointer to 32bit
integer) as argument, not "long *" as specified in qemu.  Using the
correct type makes the emulation work in cross endian context.

Both ioctl does not seem to be documented. However the kernel
implementation has always used "int *".

Signed-off-by: Bastian Blank <waldi@debian.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3185
---
 linux-user/ioctls.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
index 3b41128..2f62fd2 100644
--- a/linux-user/ioctls.h
+++ b/linux-user/ioctls.h
@@ -130,7 +130,7 @@
      IOCTL(FDTWADDLE, 0, TYPE_NULL)
      IOCTL(FDEJECT, 0, TYPE_NULL)
 
-     IOCTL(FIBMAP, IOC_W | IOC_R, MK_PTR(TYPE_LONG))
+     IOCTL(FIBMAP, IOC_W | IOC_R, MK_PTR(TYPE_INT))
 #ifdef FICLONE
      IOCTL(FICLONE, IOC_W, TYPE_INT)
      IOCTL(FICLONERANGE, IOC_W, MK_PTR(MK_STRUCT(STRUCT_file_clone_range)))
@@ -145,7 +145,7 @@
      IOCTL(FITRIM, IOC_W | IOC_R, MK_PTR(MK_STRUCT(STRUCT_fstrim_range)))
 #endif
 
-     IOCTL(FIGETBSZ, IOC_R, MK_PTR(TYPE_LONG))
+     IOCTL(FIGETBSZ, IOC_R, MK_PTR(TYPE_INT))
 #ifdef CONFIG_FIEMAP
      IOCTL_SPECIAL(FS_IOC_FIEMAP, IOC_W | IOC_R, do_ioctl_fs_ioc_fiemap,
                    MK_PTR(MK_STRUCT(STRUCT_fiemap)))
-- 
2.51.0

Re: [PATCH v2] linux-user: Use correct type for FIBMAP and FIGETBSZ emulation

Posted by Michael Tokarev 2 weeks, 3 days ago

On 10/28/25 15:16, Bastian Blank wrote:
> Both the FIBMAP and FIGETBSZ ioctl get "int *" (pointer to 32bit
> integer) as argument, not "long *" as specified in qemu.  Using the
> correct type makes the emulation work in cross endian context.
> 
> Both ioctl does not seem to be documented. However the kernel
> implementation has always used "int *".
> 
> Signed-off-by: Bastian Blank <waldi@debian.org>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3185

Reviwed-by: Michael Tokarev <mjt@tls.msk.ru>

Again, I can pick this up through qemu-trivial if there's no
objection, Laurent?

And Cc: qemu-stable.

Thanks,

/mjt

Re: [PATCH v2] linux-user: Use correct type for FIBMAP and FIGETBSZ emulation

Posted by Richard Henderson 2 weeks, 2 days ago

On 10/28/25 14:55, Michael Tokarev wrote:
> On 10/28/25 15:16, Bastian Blank wrote:
>> Both the FIBMAP and FIGETBSZ ioctl get "int *" (pointer to 32bit
>> integer) as argument, not "long *" as specified in qemu.  Using the
>> correct type makes the emulation work in cross endian context.
>>
>> Both ioctl does not seem to be documented. However the kernel
>> implementation has always used "int *".
>>
>> Signed-off-by: Bastian Blank <waldi@debian.org>
>> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3185
> 
> Reviwed-by: Michael Tokarev <mjt@tls.msk.ru>
> 
> Again, I can pick this up through qemu-trivial if there's no
> objection, Laurent?

Please do.

r~

Re: [PATCH v2] linux-user: Use correct type for FIBMAP and FIGETBSZ emulation

Posted by Peter Maydell 2 weeks, 3 days ago

On Tue, 28 Oct 2025 at 12:58, Bastian Blank <bblank@thinkmo.de> wrote:
>
> Both the FIBMAP and FIGETBSZ ioctl get "int *" (pointer to 32bit
> integer) as argument, not "long *" as specified in qemu.  Using the
> correct type makes the emulation work in cross endian context.
>
> Both ioctl does not seem to be documented. However the kernel
> implementation has always used "int *".
>
> Signed-off-by: Bastian Blank <waldi@debian.org>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3185
> ---

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [PATCH v2] linux-user: Use correct type for FIBMAP and FIGETBSZ emulation

Posted by Helge Deller 2 weeks, 3 days ago

On 10/28/25 14:11, Peter Maydell wrote:
> On Tue, 28 Oct 2025 at 12:58, Bastian Blank <bblank@thinkmo.de> wrote:
>>
>> Both the FIBMAP and FIGETBSZ ioctl get "int *" (pointer to 32bit
>> integer) as argument, not "long *" as specified in qemu.  Using the
>> correct type makes the emulation work in cross endian context.
>>
>> Both ioctl does not seem to be documented. However the kernel
>> implementation has always used "int *".
>>
>> Signed-off-by: Bastian Blank <waldi@debian.org>
>> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3185
>> ---
> 
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Helge Deller <deller@gmx.de>