QEMU fails to honor O_TMPFILE

Qemu-devel New Thiago Macieira 4 participants 6 messages Aug 7, 2017 – Dec 15, 2017

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Thiago Macieira

author

2017-08-07 20:31 UTC #0 lore raw

Public bug reported:

When making a call like

  open("/tmp", O_TMPFILE | O_RDWR);

under QEMU, we ged -EISDIR.

Under any kernel 3.11 or later, we are supposed to get an unnamed file in /tmp. In case the filesystem for /tmp does not support unnamed files, we are supposed to get EOPNOTSUPP.

[I don't know the QEMU version, since this happened in a system I don't have access to]

** Affects: qemu
Importance: Undecided
Status: New

Signature · 26 lines

You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1709170

Title:
  QEMU fails to honor O_TMPFILE

Status in QEMU:
  New

Bug description:
  When making a call like

    open("/tmp", O_TMPFILE | O_RDWR);

  under QEMU, we ged -EISDIR.

  Under any kernel 3.11 or later, we are supposed to get an unnamed file
  in /tmp. In case the filesystem for /tmp does not support unnamed
  files, we are supposed to get EOPNOTSUPP.

  [I don't know the QEMU version, since this happened in a system I
  don't have access to]

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1709170/+subscriptions

Riku Voipio

2017-08-08 06:56 UTC #1 lore raw

Hi Thiago,

What is the version of glibc on the targets you are building to? There was an O_TMPFILE bug in older glibc's:

https://sourceware.org/bugzilla/show_bug.cgi?id=17912

** Bug watch added: Sourceware.org Bugzilla #17912
https://sourceware.org/bugzilla/show_bug.cgi?id=17912

Signature · 26 lines

You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1709170

Title:
  QEMU fails to honor O_TMPFILE

Status in QEMU:
  New

Bug description:
  When making a call like

    open("/tmp", O_TMPFILE | O_RDWR);

  under QEMU, we ged -EISDIR.

  Under any kernel 3.11 or later, we are supposed to get an unnamed file
  in /tmp. In case the filesystem for /tmp does not support unnamed
  files, we are supposed to get EOPNOTSUPP.

  [I don't know the QEMU version, since this happened in a system I
  don't have access to]

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1709170/+subscriptions

Riku Voipio

2017-08-08 13:19 UTC #2 lore raw

In reply to Thiago Macieira

Quoted 11 lines · Thiago Macieira

Public bug reported:
When making a call like
  open("/tmp", O_TMPFILE | O_RDWR);
under QEMU, we ged -EISDIR.
Under any kernel 3.11 or later, we are supposed to get an unnamed file in /tmp. In case the filesystem for /tmp does not support unnamed files, we are supposed to get EOPNOTSUPP.

Actually, -EISDIR is valid error when underlying system doesn't support O_TMPFILE. See man openat or the kernel definition for O_TMPFILE.

Regardless, I'm submitting a patch to properly translate the O_TMPFILE.

Riku

Riku Voipio

2017-08-08 13:31 UTC #3 lore raw

PATCH 1/1 linux-user: fix O_TMPFILE handling

In reply to Thiago Macieira

Since O_TMPFILE might differ between guest and host,
add it to the bitmask_transtbl. While at it, fix the definitions of O_DIRECTORY etc on arm64, which are identical to arm32 according to kernel sources.

This fixes open14 and openat03 ltp testcases.

Fixes https://bugs.launchpad.net/qemu/+bug/1709170

---
 linux-user/strace.c       | 4 ++++
 linux-user/syscall.c      | 3 +++
 linux-user/syscall_defs.h | 8 +++++++-
 3 files changed, 14 insertions(+), 1 deletion(-)

linux-user/strace.c +4 -0

index d821d165ff..bd897a3f20 100644
@@ -838,6 +838,10 @@ UNUSED static struct flags open_flags[] = {
 #ifdef O_PATH
     FLAG_TARGET(O_PATH),
 #endif
+#ifdef O_TMPFILE
+    FLAG_TARGET(O_TMPFILE),
+    FLAG_TARGET(__O_TMPFILE),
+#endif
     FLAG_END,
 };

linux-user/syscall.c +3 -0

index 54343c06be..b3aa8099b4 100644
@@ -342,6 +342,9 @@ static bitmask_transtbl fcntl_flags_tbl[] = {
 #if defined(O_PATH)
   { TARGET_O_PATH,      TARGET_O_PATH,      O_PATH,      O_PATH       },
 #endif
+#if defined(O_TMPFILE)
+  { TARGET_O_TMPFILE,   TARGET_O_TMPFILE,   O_TMPFILE,   O_TMPFILE    },
+#endif
   /* Don't terminate the list prematurely on 64-bit host+guest.  */
 #if TARGET_O_LARGEFILE != 0 || O_LARGEFILE != 0
   { TARGET_O_LARGEFILE, TARGET_O_LARGEFILE, O_LARGEFILE, O_LARGEFILE, },

linux-user/syscall_defs.h +7 -1

index 40c5027e93..6e2287e918 100644
@@ -2416,7 +2416,7 @@ struct target_statfs64 {
 #define TARGET_O_CLOEXEC     010000000
 #define TARGET___O_SYNC      000100000
 #define TARGET_O_PATH        020000000
-#elif defined(TARGET_ARM) || defined(TARGET_M68K)
+#elif defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_AARCH64)
 #define TARGET_O_DIRECTORY      040000 /* must be a directory */
 #define TARGET_O_NOFOLLOW      0100000 /* don't follow links */
 #define TARGET_O_DIRECT        0200000 /* direct disk access hint */

@@ -2513,6 +2513,12 @@ struct target_statfs64 {
 #ifndef TARGET_O_PATH
 #define TARGET_O_PATH        010000000
 #endif
+#ifndef TARGET___O_TMPFILE
+#define TARGET___O_TMPFILE   020000000
+#endif
+#ifndef TARGET_O_TMPFILE
+#define TARGET_O_TMPFILE     (TARGET___O_TMPFILE | TARGET_O_DIRECTORY)
+#endif
 #ifndef TARGET_O_NDELAY
 #define TARGET_O_NDELAY  TARGET_O_NONBLOCK
 #endif

Signature · 29 lines

2.11.0

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1709170

Title:
  QEMU fails to honor O_TMPFILE

Status in QEMU:
  New

Bug description:
  When making a call like

    open("/tmp", O_TMPFILE | O_RDWR);

  under QEMU, we ged -EISDIR.

  Under any kernel 3.11 or later, we are supposed to get an unnamed file
  in /tmp. In case the filesystem for /tmp does not support unnamed
  files, we are supposed to get EOPNOTSUPP.

  [I don't know the QEMU version, since this happened in a system I
  don't have access to]

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1709170/+subscriptions

Thiago Macieira

author

2017-08-08 22:05 UTC #4 lore raw

In reply to Thiago Macieira

It was a Yocto 2.0 sysroot running on an Ubuntu 16.04 host.

Signature · 26 lines

You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1709170

Title:
  QEMU fails to honor O_TMPFILE

Status in QEMU:
  New

Bug description:
  When making a call like

    open("/tmp", O_TMPFILE | O_RDWR);

  under QEMU, we ged -EISDIR.

  Under any kernel 3.11 or later, we are supposed to get an unnamed file
  in /tmp. In case the filesystem for /tmp does not support unnamed
  files, we are supposed to get EOPNOTSUPP.

  [I don't know the QEMU version, since this happened in a system I
  don't have access to]

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1709170/+subscriptions

Thomas Huth

2017-12-15 15:45 UTC #5 lore raw

In reply to Thiago Macieira

Fix has been released with QEMU 2.11:
https://git.qemu.org/?p=qemu.git;a=commitdiff;h=5f9cee46cd4ec4600e1a

** Changed in: qemu
Status: New => Fix Released

Signature · 26 lines

You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1709170

Title:
  QEMU fails to honor O_TMPFILE

Status in QEMU:
  Fix Released

Bug description:
  When making a call like

    open("/tmp", O_TMPFILE | O_RDWR);

  under QEMU, we ged -EISDIR.

  Under any kernel 3.11 or later, we are supposed to get an unnamed file
  in /tmp. In case the filesystem for /tmp does not support unnamed
  files, we are supposed to get EOPNOTSUPP.

  [I don't know the QEMU version, since this happened in a system I
  don't have access to]

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1709170/+subscriptions