[PULL,03/38] bsd-user: Propagate alignment argument to mmap_find_vma()

Commit Message

Philippe Mathieu-Daudé March 9, 2025, 5:51 p.m. UTC

Propagate the alignment to mmap_find_vma(), effectively
embedding mmap_find_vma_aligned() within mmap_find_vma().

Add a comment in do_bsd_shmat() to clarify alignment above
page size is not required.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
Reviewed-by: Warner Losh <[e-mail]>
Message-Id: <[e-mail]>
---
 bsd-user/bsd-mem.h |  4 +++-
 bsd-user/qemu.h    |  2 +-
 bsd-user/mmap.c    | 10 ++--------
 3 files changed, 6 insertions(+), 10 deletions(-)

Patch

diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h
index f5ec0de24ca..90ca0e33775 100644
--- a/bsd-user/bsd-mem.h
+++ b/bsd-user/bsd-mem.h
@@ -370,9 +370,11 @@  static inline abi_long do_bsd_shmat(int shmid, abi_ulong shmaddr, int shmflg)
         if (shmaddr) {
             host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
         } else {
+            abi_ulong alignment;
             abi_ulong mmap_start;
 
-            mmap_start = mmap_find_vma(0, shm_info.shm_segsz);
+            alignment = 0; /* alignment above page size not required */
+            mmap_start = mmap_find_vma(0, shm_info.shm_segsz, alignment);
 
             if (mmap_start == -1) {
                 return -TARGET_ENOMEM;
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
index 4e97c796318..0b3bd65b180 100644
--- a/bsd-user/qemu.h
+++ b/bsd-user/qemu.h
@@ -242,7 +242,7 @@  abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
                        abi_ulong new_addr);
 int target_msync(abi_ulong start, abi_ulong len, int flags);
 extern abi_ulong mmap_next_start;
-abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size);
+abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong alignment);
 void mmap_reserve(abi_ulong start, abi_ulong size);
 void TSA_NO_TSA mmap_fork_start(void);
 void TSA_NO_TSA mmap_fork_end(int child);
diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index dfa6e728ab5..3f0df79c375 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -275,8 +275,7 @@  static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
  * It must be called with mmap_lock() held.
  * Return -1 if error.
  */
-static abi_ulong mmap_find_vma_aligned(abi_ulong start, abi_ulong size,
-                                       abi_ulong alignment)
+abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong alignment)
 {
     void *ptr, *prev;
     abi_ulong addr;
@@ -395,11 +394,6 @@  static abi_ulong mmap_find_vma_aligned(abi_ulong start, abi_ulong size,
     }
 }
 
-abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
-{
-    return mmap_find_vma_aligned(start, size, 0);
-}
-
 /* NOTE: all the constants are the HOST ones */
 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
                      int flags, int fd, off_t offset)
@@ -494,7 +488,7 @@  abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
         host_len = len + offset - host_offset;
         host_len = HOST_PAGE_ALIGN(host_len);
         alignment = (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT;
-        start = mmap_find_vma_aligned(real_start, host_len, alignment);
+        start = mmap_find_vma(real_start, host_len, alignment);
         if (start == (abi_ulong)-1) {
             errno = ENOMEM;
             goto fail;