powerpc/vas: Return -EINVAL if the offset is non-zero in mmap()

[ Upstream commit 0d67f0dee6c9176bc09a5482dd7346e3a0f14d0b ]

The user space calls mmap() to map VAS window paste address
and the kernel returns the complete mapped page for each
window. So return -EINVAL if non-zero is passed for offset
parameter to mmap().

See Documentation/arch/powerpc/vas-api.rst for mmap()
restrictions.

Co-developed-by: Jonathan Greental <yonatan02greental@gmail.com>
Signed-off-by: Jonathan Greental <yonatan02greental@gmail.com>
Reported-by: Jonathan Greental <yonatan02greental@gmail.com>
Fixes: dda44eb29c ("powerpc/vas: Add VAS user space API")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250610021227.361980-2-maddy@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Haren Myneni
2025-06-10 07:42:27 +05:30
committed by Greg Kroah-Hartman
parent 8635e325b8
commit d2fc85c90b

View File

@@ -521,6 +521,15 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
return -EINVAL;
}
/*
* Map complete page to the paste address. So the user
* space should pass 0ULL to the offset parameter.
*/
if (vma->vm_pgoff) {
pr_debug("Page offset unsupported to map paste address\n");
return -EINVAL;
}
/* Ensure instance has an open send window */
if (!txwin) {
pr_err("No send window open?\n");