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Date: Mon, 19 Oct 2020 15:46:20 +0200
From: Jan Hubicka <hubicka@ucw.cz>
To: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
Cc: gcc-bugs@gcc.gnu.org
Subject: Re: [Bug gcov-profile/97461] [11 Regression] allocate_gcov_kvp()
 deadlocks in firefox LTO+PGO build (overridden malloc() recursion)
Message-ID: <20201019134620.GC69903@kam.mff.cuni.cz>
References: <bug-97461-4@http.gcc.gnu.org/bugzilla/>
 <bug-97461-4-AvuZH7NjEx@http.gcc.gnu.org/bugzilla/>
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> No. The only thing we support is a recursive malloc as seen in:
> ./gcc/testsuite/gcc.dg/tree-prof/indir-call-prof-malloc.c
> 
> It was added in g:bc2b1a232b1825b421a1aaa21a0865b2d1e4e08c as we use a
> statically allocated buffer when we recursively entry allocate_gcov_kvp.
> 
> However this is different as we can't call malloc/calloc from the function as
> we're in code that initializes a memory allocator.
> 
> We can mitigate the issue with a pair of new functions __gcov_supress_malloc
> and __gcov_alloc_malloc that will be called by a custom memory allocator.
> 
> What do you think about it?

How this works with the llvm implementation (that is very similar here,
right?)

Honza