Bug 1458 – mremap() fifth argument and MREMAP_FIXED not exposed in glibc

Bug 1458 - mremap() fifth argument and MREMAP_FIXED not exposed in glibc


Summary:	mremap() fifth argument and MREMAP_FIXED not exposed in glibc

Status:	RESOLVED FIXED

Product:	glibc
Classification:	Unclassified
Component:	libc
Version:	2.3.5

Importance:	P2 normal
Target Milestone:	---
Assigned To:	GOTO Masanori

URL:
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2005-10-11 07:33 UTC by Michael Kerrisk
Modified:	2007-11-17 07:22 UTC (History)
CC List:	1 user (show)

See Also:
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Last reconfirmed:

Attachments
Patch to fix REMAP_FIXED not defined error on MIPS and ALPHA (699 bytes, patch) 2005-10-18 07:10 UTC, Jim Gifford	Details \| Diff
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Description Michael Kerrisk 2005-10-11 07:33:51 UTC

Since 2.3.31, the Linux kernel has allowed an additional 'flags' value for
mremap(): MREMAP_FIXED (defined with the value 2), which serves a similar
purpose to the mmap() MAP_FIXED flag.  If this flag is supplied, then mremap()
employs a fifth argument, 'new_address', which specifies a fixed address to
which the mapping should be relocated.  Currently, glibc does not expose the
MREMAP_FIXED definition and the mremap() prototype does not expose the fifth
argument.  Can these definitions please be exposed in glibc.

Comment 1 Ulrich Drepper 2005-10-14 13:42:57 UTC

I made the necessary changes for several architectures in the CVS trunk.

Comment 2 Jim Gifford 2005-10-18 07:10:16 UTC

Unable to compile current snapshot(1017) on MIPS and ALPHA without 
# define MREMAP_FIXED   2
added to mman.h to sysdeps/unix/sysv/linux/alpha/bits/mman.h
sysdeps/unix/sysv/linux/mips/bits/mman.h.

Will attach patch

Comment 3 Jim Gifford 2005-10-18 07:10:53 UTC

Created attachment 719 [details]
Patch to fix REMAP_FIXED not defined error on MIPS and ALPHA

Comment 4 Ulrich Drepper 2005-12-23 04:07:26 UTC

The patch is not needed anymore.

Comment 5 Arun Sharma 2007-11-17 07:22:07 UTC

Making mremap() a function with variable number of arguments changes the ABI on
x86_64. Code compiled before this change will treat %rax as scratch. After the
change, the calling conventions expect %al to be set to the number of XMM
registers passed.

Is there a reason why mremap was not versioned after the change?