[Qemu-devel] [Bug 1810433] [NEW] aarch64-linux-user master: inconsistent pwrite behaviour

[Qemu-devel] [Bug 1810433] [NEW] aarch64-linux-user master: inconsistent pwrite behaviour

[Matwey V. Kornilov]

Public bug reported:

Hello,

I am running aarch64-linux-user from master, commit
20d6c7312f1b812bb9c750f4087f69ac8485cc90

And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
Minimal reproducible sample is the following:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>

/*
 System                  | Result
-------------------------+----------------
 Native x86_64 4.12.14   | pwrite ret = 0
 Native aarch64 4.4.159  | pwrite ret = 0
 qemu-aarch64 at x86_64  | pwrite ret = -1
   ( 20d6c7312f1b8 )     |
*/

int main(int argc, char** argv) {
 int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
 if (fd < 0) {
  perror("open");
  return 1;
 }

 int ret = fallocate(fd, 0, 0, 1000);
 if (ret < 0) {
  perror("fallocate");
  return 1;
 }

 ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
 printf("pwrite ret = %ld\n", ret_pwrite);

 close(fd);

 return 0;
}


Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

** Affects: qemu
     Importance: Undecided
         Status: New

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

To manage notifications about this bug go to:
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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Matwey V. Kornilov]

** Attachment added: "Test case source file"
   https://bugs.launchpad.net/qemu/+bug/1810433/+attachment/5226714/+files/main.c

** Description changed:

  Hello,
  
  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90
  
  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:
  
  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>
  
  /*
-  System                  | Result
+  System                  | Result
  -------------------------+----------------
-  Native x86_64 4.12.14   | pwrite ret = 0
-  Native aarch64 4.4.159  | pwrite ret = 0
-  qemu-aarch64 at x86_64  | pwrite ret = -1
-    ( 20d6c7312f1b8 )     |
+  Native x86_64 4.12.14   | pwrite ret = 0
+  Native aarch64 4.4.159  | pwrite ret = 0
+  qemu-aarch64 at x86_64  | pwrite ret = -1
+    ( 20d6c7312f1b8 )     |
  */
  
  int main(int argc, char** argv) {
- 	int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
- 	if (fd < 0) {
- 		perror("open");
- 		return 1;
- 	}
+  int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
+  if (fd < 0) {
+   perror("open");
+   return 1;
+  }
  
- 	int ret = fallocate(fd, 0, 0, 1000);
- 	if (ret < 0) {
- 		perror("fallocate");
- 		return 1;
- 	}
+  int ret = fallocate(fd, 0, 0, 1000);
+  if (ret < 0) {
+   perror("fallocate");
+   return 1;
+  }
  
- 	ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
- 	printf("pwrite ret = %ld\n", ret_pwrite);
+  ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
+  printf("pwrite ret = %ld\n", ret_pwrite);
  
-         close(fd);
+  close(fd);
  
- 	return 0;
+  return 0;
  }
+ 
+ 
+ Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Matwey V. Kornilov]

** Attachment added: "Test binary statically compiled for aarch64"
   https://bugs.launchpad.net/qemu/+bug/1810433/+attachment/5226715/+files/pwrite_test.aarch64

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Peter Maydell]

This seems related to commit 58cfa6c2e6eb51b23cc98f8, where this was
fixed for the write() syscall. In that commit message the author writes
"Q. Do pread64/pwrite64 need to be changed similarly? A. Experiment
suggests not: both linux and linux-user yield -1 for NULL 0-length
reads/writes." That doesn't match your results, though, and looking at
the source both write and pwrite syscalls go through the vfs_write()
function, so their behaviour for a NULL/0 buffer should be identical.

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

To manage notifications about this bug go to:
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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Peter Maydell]

strace from an aarch64 machine:
pwrite64(3, NULL, 0, 0)                 = 0

strace from QEMU:
32029 pwrite64(3,0,0,0,4797560,0) = -1 errno=14 (Bad address)

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Matwey V. Kornilov]

Do you know how to fix it?

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

To manage notifications about this bug go to:
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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Peter Maydell]

It should be a patch pretty similar to commit 58cfa6c2e6eb51b23cc98f8,
but in the pwrite64 codepath. Slightly complicated by needing to deal
with the offset possibly being in two input arguments, but basically the
same thing.

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Matwey V. Kornilov]

It would be great if you could fix it.

Also, there are probably should exist POSIX conformance test suites
around the world. As far as I understand, this particular issue could be
found by running such a test under qemu-linux-user. I mean what if there
are other similar issues?

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

To manage notifications about this bug go to:
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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Peter Maydell]

We run the Linux Test Project LTP test suite. However I think it may not
cover this corner case. (It's also possible I missed it last time I went
through our failure results -- it's a lot of analysis effort to
disentangle "QEMU bug" from "QEMU missing feature that's impracticably
hard to implement" from "test case bug", and sometimes tests roll up
multiple tests into a single test binary that include things from
several of those cases, which means that it's harder to notice when
something that should have passed did not.)

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

To manage notifications about this bug go to:
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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Matwey V. Kornilov]

I've also check qemu-arm with the same test code. Surprisingly, I see
correct result:

pwrite ret = 0

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Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  New

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Peter Maydell]

Proposed patch at https://patchwork.ozlabs.org/patch/1022092/

NB: my guess is that your pwrite on 32-bit arm test is behaving like
that because it isn't going via the pwrite64 syscall, or possibly
because glibc there is dealing with the NULL special case early. Use
QEMU's -strace argument (or strace on real h/w) to see what libc is
actually turning that pwrite() function call into at the syscall level.


** Changed in: qemu
       Status: New => In Progress

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https://bugs.launchpad.net/bugs/1810433

Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  In Progress

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Peter Maydell]

Commit now in QEMU master as 2bd3f8998e1e7dcd9afc29fab25. This will be
in the next release: QEMU 4.0.


** Changed in: qemu
       Status: In Progress => Fix Committed

-- 
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1810433

Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  Fix Committed

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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Re: [Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Matwey V. Kornilov]

Thank you!

пт, 18 янв. 2019 г. в 19:36, Peter Maydell <peter.maydell@linaro.org>:
>
> Commit now in QEMU master as 2bd3f8998e1e7dcd9afc29fab25. This will be
> in the next release: QEMU 4.0.
>
>
> ** Changed in: qemu
>        Status: In Progress => Fix Committed
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1810433
>
> Title:
>   aarch64-linux-user master: inconsistent pwrite behaviour
>
> Status in QEMU:
>   Fix Committed
>
> Bug description:
>   Hello,
>
>   I am running aarch64-linux-user from master, commit
>   20d6c7312f1b812bb9c750f4087f69ac8485cc90
>
>   And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
>   Minimal reproducible sample is the following:
>
>   #define _GNU_SOURCE
>   #include <stdlib.h>
>   #include <stdio.h>
>   #include <unistd.h>
>   #include <sys/types.h>
>   #include <sys/stat.h>
>   #include <fcntl.h>
>   #include <string.h>
>
>   /*
>    System                  | Result
>   -------------------------+----------------
>    Native x86_64 4.12.14   | pwrite ret = 0
>    Native aarch64 4.4.159  | pwrite ret = 0
>    qemu-aarch64 at x86_64  | pwrite ret = -1
>      ( 20d6c7312f1b8 )     |
>   */
>
>   int main(int argc, char** argv) {
>    int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
>    if (fd < 0) {
>     perror("open");
>     return 1;
>    }
>
>    int ret = fallocate(fd, 0, 0, 1000);
>    if (ret < 0) {
>     perror("fallocate");
>     return 1;
>    }
>
>    ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
>    printf("pwrite ret = %ld\n", ret_pwrite);
>
>    close(fd);
>
>    return 0;
>   }
>
>
>   Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/1810433/+subscriptions


-- 
With best regards,
Matwey V. Kornilov

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1810433

Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  Fix Committed

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

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[Qemu-devel] [Bug 1810433] Re: aarch64-linux-user master: inconsistent pwrite behaviour

[Thomas Huth]

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

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1810433

Title:
  aarch64-linux-user master: inconsistent pwrite behaviour

Status in QEMU:
  Fix Released

Bug description:
  Hello,

  I am running aarch64-linux-user from master, commit
  20d6c7312f1b812bb9c750f4087f69ac8485cc90

  And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
  Minimal reproducible sample is the following:

  #define _GNU_SOURCE
  #include <stdlib.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <string.h>

  /*
   System                  | Result
  -------------------------+----------------
   Native x86_64 4.12.14   | pwrite ret = 0
   Native aarch64 4.4.159  | pwrite ret = 0
   qemu-aarch64 at x86_64  | pwrite ret = -1
     ( 20d6c7312f1b8 )     |
  */

  int main(int argc, char** argv) {
   int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
   if (fd < 0) {
    perror("open");
    return 1;
   }

   int ret = fallocate(fd, 0, 0, 1000);
   if (ret < 0) {
    perror("fallocate");
    return 1;
   }

   ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
   printf("pwrite ret = %ld\n", ret_pwrite);

   close(fd);

   return 0;
  }

  
  Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user

To manage notifications about this bug go to:
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