Date: Tue, 1 Sep 2015 15:43:57 +0000 (UTC) From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r287369 - head/libexec/rtld-elf Message-ID: <201509011543.t81FhvxT068019@repo.freebsd.org>
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Author: andrew Date: Tue Sep 1 15:43:56 2015 New Revision: 287369 URL: https://svnweb.freebsd.org/changeset/base/287369 Log: Ensure we use calculate_first_tls_offset, even if the main program doesn't have TLS program header. This is needed on architectures with Variant I tls, that is arm, arm64, mips, and powerpc. These place the thread control block at the start of the buffer and, without this, this data may be trashed. This appears to not be an issue on mips or powerpc as they include a second adjustment to move the thread local data, however this is on arm64 (with a future change to fix placing this data), and should be on arm. I am unable to trigger this on arm, even after changing the code to move the data around to make it more likely to be hit. This is most likely because my tests didn't use the variable in offset 0. Reviewed by: kib MFC after: 1 week Sponsored by: ABT Systems Ltd Modified: head/libexec/rtld-elf/rtld.c Modified: head/libexec/rtld-elf/rtld.c ============================================================================== --- head/libexec/rtld-elf/rtld.c Tue Sep 1 15:28:35 2015 (r287368) +++ head/libexec/rtld-elf/rtld.c Tue Sep 1 15:43:56 2015 (r287369) @@ -4611,7 +4611,7 @@ allocate_tls_offset(Obj_Entry *obj) return true; } - if (obj->tlsindex == 1) + if (tls_last_offset == 0) off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); else off = calculate_tls_offset(tls_last_offset, tls_last_size,
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