[rpms/gdb] gdb-17.2-rebase-f44: Backport vDSO regression.

[Jan Kratochvil <jan.kratochvil@redhat.com>]

            A new commit has been pushed.

            Repo   : rpms/gdb
            Branch : gdb-17.2-rebase-f44
            Commit : 8095c33951bd97b77f42126e1673226aed6f1508
            Author : Jan Kratochvil <jan.kratochvil@redhat.com>
            Date   : 2014-10-27T15:47:21+01:00
            Stats  : +163/-25 in 3 file(s)
            URL    : https://src.fedoraproject.org/rpms/gdb/c/8095c33951bd97b77f42126e1673226aed6f1508?branch=gdb-17.2-rebase-f44

            Log:
            Backport vDSO regression.

- Revert the makeinfo workaround from 7.8-27.fc21.
- Further 1.75x improvement of the interactive symbols lookup (Doug Evans).

---
diff --git a/gdb-symbols-lookup-accel.patch b/gdb-symbols-lookup-accel.patch
index 4c90f78..1901d07 100644
--- a/gdb-symbols-lookup-accel.patch
+++ b/gdb-symbols-lookup-accel.patch
@@ -78,49 +78,91 @@ index 055c87e..90bcd6d 100644
 
 --17pEHd4RhPHOinZp--
 
-http://sourceware.org/ml/gdb-patches/2014-10/msg00525.html
-Subject: [patch 2/2] Accelerate lookup_symbol_aux_objfile 8x
 
 
---K8nIJk4ghYZn606h
+http://sourceware.org/ml/gdb-patches/2014-10/msg00612.html
+Subject: [patchv2 2/2] Accelerate lookup_symbol_aux_objfile 14.5x  [Re: [patch 0/2] Accelerate symbol lookups 15x]
+
+
+--vtzGhvizbBRQ85DL
 Content-Type: text/plain; charset=us-ascii
 Content-Disposition: inline
 
-Hi,
+On Wed, 22 Oct 2014 10:55:18 +0200, Doug Evans wrote:
+> For example, the count of calls to dict_hash before/after goes from 13.8M to 31.
+> I'm guessing one t hing we're doing here is coping with an artifact of
+> dwz:
+
+During my simple test on non-DWZ file (./gdb itself) it went 3684->3484.
+
+The problem is that dict_cash(val) is called for the same val for each block
+(== symtab).
+
+On DWZ the saving is probably much larger as there are many more symtabs due
+to DW_TAG_partial_unit ones.
+
+
+> what was once one global block to represent the entire objfile is
+> now N.
+
+Without DWZ there are X global blocks for X primary symtabs for X CUs of
+objfile.  With DWZ there are X+Y global blocks for X+Y primary symtabs for
+X+Y CUs where Y are 'DW_TAG_partial_unit's.
 
-lookup_symbol_aux_objfile() processing is very ineffective.  For each primary
-symtab it searches it and also all its secondary symtabs.  But that means that
-secondary symtabs included in many primary symtabs get needlessly searched
-many times during one lookup_symbol_aux_objfile() run.
+For 'DW_TAG_partial_unit's (Ys) their blockvector is usually empty.  But not
+always, I have found there typedef symbols, there can IMO be optimized-out
+static variables etc.
 
-lookup_symbol_aux_objfile does not care in which primary/secondary symtab the
-symbol is found.
 
+> [I'm sure the patches help in the non-dwz case, but I suspect it's less.
+> Which isn't to say the patches aren't useful.
+> I just need play with a few more examples.]
 
+I agree.
+
+[patch 2/2] could needlessly performance-regress non-DWZ cases, therefore
+I have put back original ALL_OBJFILE_PRIMARY_SYMTABS (instead of my
+ALL_OBJFILE_SYMTABS) as it is perfectly sufficient.  For the performance
+testcase of mine:
+
+Benchmark on non-trivial application with    'p <tab><tab>':
+Command execution time:   4.215000 (cpu),   4.241466 (wall) --- both fixes with new [patch 2/2]
+Command execution time:   7.373000 (cpu),   7.395095 (wall) --- both fixes
+Command execution time:  13.572000 (cpu),  13.592689 (wall) --- just lookup_symbol_aux_objfile fix
+Command execution time: 113.036000 (cpu), 113.067995 (wall) --- FSF GDB HEAD
+
+That is additional 1.75x improvement, making the total improvement 26.8x.
+
+
+No regressions on {x86_64,x86_64-m32,i686}-fedora21pre-linux-gnu in standard
+and .gdb_index-enabled runs.  Neither of the patches should cause any visible
+behavior change.
+
+
+Thanks,
 Jan
 
---K8nIJk4ghYZn606h
+--vtzGhvizbBRQ85DL
 Content-Type: text/plain; charset=us-ascii
-Content-Disposition: inline; filename="idxcache2.patch"
+Content-Disposition: inline; filename="idxcache2doug.patch"
 
 gdb/
-2014-10-20  Jan Kratochvil  <jan.kratochvil@redhat.com>
+2014-10-23  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	* symtab.c (lookup_symbol_aux_objfile): Use ALL_OBJFILE_SYMTABS, inline
 	lookup_block_symbol.
 
 diff --git a/gdb/symtab.c b/gdb/symtab.c
-index c530d50..bc800ef 100644
+index c530d50..da13861 100644
 --- a/gdb/symtab.c
 +++ b/gdb/symtab.c
 @@ -1657,15 +1657,25 @@ lookup_symbol_aux_objfile (struct objfile *objfile, int block_index,
    const struct block *block;
    struct symtab *s;
  
--  ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
 +  gdb_assert (block_index == GLOBAL_BLOCK || block_index == STATIC_BLOCK);
 +
-+  ALL_OBJFILE_SYMTABS (objfile, s)
+   ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
      {
 +      struct dict_iterator dict_iter;
 +
@@ -145,5 +187,5 @@ index c530d50..bc800ef 100644
      }
  
 
---K8nIJk4ghYZn606h--
+--vtzGhvizbBRQ85DL--
 

diff --git a/gdb-upstream.patch b/gdb-upstream.patch
index 9d2bac8..2c0cfc9 100644
--- a/gdb-upstream.patch
+++ b/gdb-upstream.patch
@@ -1770,3 +1770,101 @@ gdb/testsuite/
 -- 
 1.9.3
 
+
+
+commit 54fbc750b54271efb75ae11ce49f14c4234a9476
+Author: Jan Kratochvil <jan.kratochvil@redhat.com>
+Date:   Thu Sep 18 08:21:40 2014 +0200
+
+    Fix regression for Linux vDSO in GDB (PR gdb/17407).
+    
+    since
+    	5979d6b69b20a8355ea94b75fad97415fce4788c
+    	https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=5979d6b69b20a8355ea94b75fad97415fce4788c
+    	vdso handling
+    	https://sourceware.org/ml/binutils/2014-03/msg00082.html
+    	https://sourceware.org/ml/binutils/2014-04/msg00003.html
+    	Message-ID: <A78C989F6D9628469189715575E55B230AA884EB@IRSMSX104.ger.corp.intel.com>
+    I get on
+    	kernel-3.16.2-200.fc20.x86_64
+    	https://koji.fedoraproject.org/koji/buildinfo?buildID=575860
+    	attaching its vdso.bin.gz
+    GDB (FSF HEAD 5e43d46791c4c66fd83947a12d4f716b561a9103) regression:
+    reproducer:
+    	./gdb -ex start ./gdb
+    actual result / FAIL:
+    	Got object file from memory but can't read symbols: File truncated.
+    expected result / PASS:
+    	<nothing>
+    or / PASS:
+    	warning: Could not load shared library symbols for linux-vdso.so.1.
+    	Do you need "set solib-search-path" or "set sysroot"?
+    
+    That "warning: Could not load shared library..." is mostly harmless (it is
+    a bug in GDB), in the FAIL case it is not printed just because
+    bfd_check_format() fails there.
+    
+    It seems logical to me this way when the 'size' parameter has been already
+    added.
+    Alan Modra:
+    I was wrongly thinking that the section headers were
+    always last when I wrote that code.  (They are now!  If you relink
+    that vdso with current binutils master you won't hit this problem, but
+    that of course doesn't help existing kernels.)
+    
+    I do not see a regression for add-symbol-file-from-memory for libncurses.so.5
+    from the original thread above.
+    
+      Start of section headers:          1080 (bytes into file)
+      Size of section headers:           64 (bytes)
+      Number of section headers:         13
+      Section header string table index: 8
+    Section Headers:
+      [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
+      [ 8] .fake_shstrtab    STRTAB          0000000000000780 000780 000076 00   A  0   0 32
+    Program Headers:
+      Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   Flg Align
+      LOAD           0x000000 0x0000000000000000 0x0000000000000000 0x0012fe 0x0012fe R E 0x1000
+    
+    size == 0x2000
+    shdr_end == 0x778 == 1080 + 13 * 64
+    high_offset == 0x12fe
+    
+           else if (size >= shdr_end)
+    -	high_offset = shdr_end;
+    +	high_offset = size;
+    
+    But then 0x778 < 0x780 for "Section header string table index" so whole
+    bfd_check_format() fails because section headers were not cleared here:
+      /* If the segments visible in memory didn't include the section headers,
+         then clear them from the file header.  */
+      if (high_offset < shdr_end)
+    
+    bfd/ChangeLog
+    2014-09-18  Jan Kratochvil  <jan.kratochvil@redhat.com>
+    
+    	PR gdb/17407
+    	* elfcode.h (bfd_from_remote_memory): Use SIZE for HIGH_OFFSET.
+
+### a/bfd/ChangeLog
+### b/bfd/ChangeLog
+## -1,3 +1,8 @@
++2014-09-18  Jan Kratochvil  <jan.kratochvil@redhat.com>
++
++	PR gdb/17407
++	* elfcode.h (bfd_from_remote_memory): Use SIZE for HIGH_OFFSET.
++
+ 2014-07-16  H.J. Lu  <hongjiu.lu@intel.com>
+ 
+ 	* elf32-i386.c (elf_i386_plt_sym_val): Match PLT entry only for
+--- a/bfd/elfcode.h
++++ b/bfd/elfcode.h
+@@ -1749,7 +1749,7 @@ NAME(_bfd_elf,bfd_from_remote_memory)
+ 	     headers.  */
+ 	}
+       else if (size >= shdr_end)
+-	high_offset = shdr_end;
++	high_offset = size;
+       else
+ 	{
+ 	  bfd_vma page_size = get_elf_backend_data (templ)->minpagesize;

diff --git a/gdb.spec b/gdb.spec
index 2ed582b..691bbef 100644
--- a/gdb.spec
+++ b/gdb.spec
@@ -26,7 +26,7 @@ Version: 7.8
 
 # The release always contains a leading reserved number, start it at 1.
 # `upstream' is not a part of `name' to stay fully rpm dependencies compatible for the testing.
-Release: 28%{?dist}
+Release: 29%{?dist}
 
 License: GPLv3+ and GPLv3+ with exceptions and GPLv2+ and GPLv2+ with exceptions and GPL+ and LGPLv2+ and BSD and Public Domain and GFDL
 Group: Development/Debuggers
@@ -897,9 +897,6 @@ mv -f readline-doc readline/doc
 %build
 rm -rf %{buildroot}
 
-# https://bugzilla.redhat.com/show_bug.cgi?id=1154436
-export PERL5LIB="$PERL5LIB${PERL5LIB:+:}/usr/share/texi2html/lib/Unicode-EastAsianWidth/lib"
-
 # Identify the build directory with the version of gdb as well as the
 # architecture, to allow for mutliple versions to be installed and
 # built.
@@ -1130,10 +1127,6 @@ echo ====================TESTING END=====================
 %endif
 
 %install
-
-# https://bugzilla.redhat.com/show_bug.cgi?id=1154436
-export PERL5LIB="$PERL5LIB${PERL5LIB:+:}/usr/share/texi2html/lib/Unicode-EastAsianWidth/lib"
-
 # Initially we're in the %{gdb_src} directory.
 cd %{gdb_build}
 rm -rf $RPM_BUILD_ROOT
@@ -1350,6 +1343,11 @@ then
 fi
 
 %changelog
+* Mon Oct 27 2014 Jan Kratochvil <jan.kratochvil@redhat.com> - 7.8-29.fc21
+- Backport vDSO regression.
+- Revert the makeinfo workaround from 7.8-27.fc21.
+- Further 1.75x improvement of the interactive symbols lookup (Doug Evans).
+
 * Mon Oct 20 2014 Jan Kratochvil <jan.kratochvil@redhat.com> - 7.8-28.fc21
 - Accelerate interactive symbols lookup 15x.