diff mbox series

[7/9] bsd-user: Don't try to mmap fd when it is -1 independently from MAP_ANONYMOUS flag

Message ID 20210917025635.32011-8-imp@bsdimp.com (mailing list archive)
State New, archived
Headers show
Series bsd-user mmap fixes | expand

Commit Message

Warner Losh Sept. 17, 2021, 2:56 a.m. UTC 
From: Guy Yur <guyyur@ngmail.com>

Switch checks for !(flags & MAP_ANONYMOUS) with checks for fd != -1.
MAP_STACK and MAP_GUARD also force fd == -1 and they don't require
mapping the fd either.

Signed-off-by: Guy Yur <guyyur@gmail.com>
[ partially merged before, finishing the job and documenting origin]
Signed-off-by: Warner Losh <imp@bsdimp.com>
---
 bsd-user/mmap.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Warner Losh Sept. 17, 2021, 2:58 a.m. UTC | #1 
On Thu, Sep 16, 2021 at 8:56 PM Warner Losh <imp@bsdimp.com> wrote:

> From: Guy Yur <guyyur@ngmail.com>
>

I need to fix this email address in the next round or for the pull request.
It's gmail.com, not ngmail.com.

Switch checks for !(flags & MAP_ANONYMOUS) with checks for fd != -1.
> MAP_STACK and MAP_GUARD also force fd == -1 and they don't require
> mapping the fd either.
>
> Signed-off-by: Guy Yur <guyyur@gmail.com>
> [ partially merged before, finishing the job and documenting origin]
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> ---
>  bsd-user/mmap.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
> index 8b763fffc3..347d314aa9 100644
> --- a/bsd-user/mmap.c
> +++ b/bsd-user/mmap.c
> @@ -154,7 +154,7 @@ static int mmap_frag(abi_ulong real_start,
>      if (prot1 == 0) {
>          /* no page was there, so we allocate one */
>          void *p = mmap(host_start, qemu_host_page_size, prot,
> -                       flags | MAP_ANON, -1, 0);
> +                       flags | ((fd != -1) ? MAP_ANON : 0), -1, 0);
>          if (p == MAP_FAILED)
>              return -1;
>          prot1 = prot;
> @@ -162,7 +162,7 @@ static int mmap_frag(abi_ulong real_start,
>      prot1 &= PAGE_BITS;
>
>      prot_new = prot | prot1;
> -    if (!(flags & MAP_ANON)) {
> +    if (fd != -1) {
>          /* msync() won't work here, so we return an error if write is
>             possible while it is a shared mapping */
>          if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
> @@ -571,7 +571,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len,
> int prot,
>           * worst case: we cannot map the file because the offset is not
>           * aligned, so we read it
>           */
> -        if (!(flags & MAP_ANON) &&
> +        if (fd != -1 &&
>              (offset & ~qemu_host_page_mask) != (start &
> ~qemu_host_page_mask)) {
>              /*
>               * msync() won't work here, so we return an error if write is
> --
> 2.32.0
>
>
diff mbox series

Patch

diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index 8b763fffc3..347d314aa9 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -154,7 +154,7 @@  static int mmap_frag(abi_ulong real_start,
     if (prot1 == 0) {
         /* no page was there, so we allocate one */
         void *p = mmap(host_start, qemu_host_page_size, prot,
-                       flags | MAP_ANON, -1, 0);
+                       flags | ((fd != -1) ? MAP_ANON : 0), -1, 0);
         if (p == MAP_FAILED)
             return -1;
         prot1 = prot;
@@ -162,7 +162,7 @@  static int mmap_frag(abi_ulong real_start,
     prot1 &= PAGE_BITS;
 
     prot_new = prot | prot1;
-    if (!(flags & MAP_ANON)) {
+    if (fd != -1) {
         /* msync() won't work here, so we return an error if write is
            possible while it is a shared mapping */
         if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
@@ -571,7 +571,7 @@  abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
          * worst case: we cannot map the file because the offset is not
          * aligned, so we read it
          */
-        if (!(flags & MAP_ANON) &&
+        if (fd != -1 &&
             (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
             /*
              * msync() won't work here, so we return an error if write is