Bug 70827

Summary:	programs with lots of shared libraries report "mmap failed" for some of them when reading symbols
Product:	[Developer tools] valgrind	Reporter:	Tom Hughes <tom>
Component:	general	Assignee:	Jeremy Fitzhardinge <jeremy>
Status:	RESOLVED FIXED
Severity:	normal	CC:	more916118
Priority:	NOR
Version First Reported In:	2.1 CVS
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Patch to make VG_(munmap) work properly

Description Tom Hughes 2003-12-19 10:26:51 UTC

Since the full virtualistion changes went in one of our programs that is linked
against about 150 shared objects has started reporting "mmap failed" for a
number of them when trying to read the symbol table.

Increasing VALGRIND_MAPSIZE stops this, but it seems that there is really a lack
of space but rather valgrind is getting confused about how much space it has
available and the call to VG_(find_map_space) at the start of VG_(mmap) starts
returning NULL for mmap's from valgrind's address space.

Comment 1 Tom Hughes 2003-12-19 11:26:36 UTC

Created attachment 3774 [details]
Patch to make VG_(munmap) work properly

It turns out that the problem is VG_(munmap) which was never actually updating
valgrind's record of the mappings because it was testing VG_(is_kerror) rather
than VG_(is_kerror)(res)...

Comment 2 Jeremy Fitzhardinge 2003-12-19 23:23:24 UTC

Well, I tried to reproduce this by making a client program which repeatedly does lots of mmap/munmap calls.  The theory being that if Valgrind's Segment list was getting corrupted, then this should trigger it.  However, it seems to work fine,
so something more subtle must be going on.

Could you add some prints to see what's being passed to VG_(find_map_space)?

Comment 3 Tom Hughes 2003-12-20 12:52:19 UTC

Subject: Re:  programs with lots of shared libraries report "mmap failed" for some of them when reading symbols         

In message <20031219222325.6918.qmail@ktown.kde.org> you wrote:

> Well, I tried to reproduce this by making a client program which repeatedly
> does lots of mmap/munmap calls.  The theory being that if Valgrind's
> Segment list was getting corrupted, then this should trigger it.  However,
> it seems to work fine, so something more subtle must be going on.
> 
> Could you add some prints to see what's being passed to VG_(find_map_space)?

Did you you not see the patch I attached to this bug after I worked
through it this morning and found the cause?

Tom

Comment 4 Jeremy Fitzhardinge 2003-12-20 19:20:03 UTC

Subject: Re:  programs with lots of shared libraries report
	"mmap failed" for some of them when reading symbols

On Sat, 2003-12-20 at 03:52, Tom Hughes wrote:
> Did you you not see the patch I attached to this bug after I worked
> through it this morning and found the cause?

No, I hadn't noticed.  Committed.  I've made that typo before...

	J

Comment 5 Jeremy Fitzhardinge 2003-12-20 21:23:36 UTC

*** Bug has been marked as fixed ***.

Comment 6 john more 2025-04-03 14:41:52 UTC

https://booksarefun.com/educators