git: b0ef93ae3f63 - stable/15 - Delete error-check code that can never happen.

The branch stable/15 has been updated by mckusick:

URL: https://cgit.FreeBSD.org/src/commit/?id=b0ef93ae3f63a31a493d00a8d9e43b411384ef51

commit b0ef93ae3f63a31a493d00a8d9e43b411384ef51
Author:     Kirk McKusick <mckusick@FreeBSD.org>
AuthorDate: 2026-03-19 00:45:23 +0000
Commit:     Kirk McKusick <mckusick@FreeBSD.org>
CommitDate: 2026-03-26 05:42:21 +0000

    Delete error-check code that can never happen.
    
    Near the top of kern_mmap() that implements the mmap(2) system call,
    it sets
    
            prot = PROT_EXTRACT(prot);
    
    with
    
    So prot can only be the three PROT_ flags.
    
    The following test of the user's mmap(2) parameters (near line 275
    in vm/vm_mmap.c):
    
            if (prot != PROT_NONE &&
                (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) != 0) {
                    return (EXTERROR(EINVAL, "invalid prot %#jx", prot));
            }
    
    can never fail. This commit deletes it.
    
    No functional change intended.
    
    Reviewed by:  kib
    Sponsored by: Netflix
    
    (cherry picked from commit 51446d33c6fbc27ce21f54ebb4c27caace48c3be)
---
 sys/vm/vm_mmap.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
index 234586893b59..cb5906440f56 100644
--- a/sys/vm/vm_mmap.c
+++ b/sys/vm/vm_mmap.c
@@ -271,10 +271,6 @@ kern_mmap(struct thread *td, const struct mmap_req *mrp)
 		return (EXTERROR(EINVAL,
 		    "both SHARED and PRIVATE set (flags %#jx)", flags));
 	}
-	if (prot != PROT_NONE &&
-	    (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) != 0) {
-		return (EXTERROR(EINVAL, "invalid prot %#jx", prot));
-	}
 	if ((flags & MAP_GUARD) != 0 && (prot != PROT_NONE || fd != -1 ||
 	    pos != 0 || (flags & ~(MAP_FIXED | MAP_GUARD | MAP_EXCL |
 	    MAP_32BIT | MAP_ALIGNMENT_MASK)) != 0)) {