From 6a0ae4aca3609401ffe2cd3e905148300fc55f6e Mon Sep 17 00:00:00 2001 From: Kevin Buettner Date: Tue, 1 Feb 2022 13:14:01 -0700 Subject: [PATCH] Fix "sect_index_data not initialized" internal error. (RHBZ 2042664, Kevin Buettner). --- _gdb.spec.Patch.include | 4 + _gdb.spec.patch.include | 1 + _patch_order | 1 + ...2042664-fix-sect_index_data-internal-error | 128 ++++++++++++++++++ gdb.spec | 6 +- 5 files changed, 139 insertions(+), 1 deletion(-) create mode 100644 gdb-rhbz2042664-fix-sect_index_data-internal-error diff --git a/_gdb.spec.Patch.include b/_gdb.spec.Patch.include index 6b1ecc6..62e69cb 100644 --- a/_gdb.spec.Patch.include +++ b/_gdb.spec.Patch.include @@ -355,3 +355,7 @@ Patch085: gdb-rhbz2024875-pr27026.patch # (RHBZ 2042257, Keith Seitz, Andrew Burgess) Patch086: gdb-rhbz2042257-ftbs-updates.patch +# Backport fix which fixes internal error due to libcc_s lacking a +# .data section. +Patch087: gdb-rhbz2042664-fix-sect_index_data-internal-error + diff --git a/_gdb.spec.patch.include b/_gdb.spec.patch.include index 965fc8c..470a7be 100644 --- a/_gdb.spec.patch.include +++ b/_gdb.spec.patch.include @@ -84,3 +84,4 @@ %patch084 -p1 %patch085 -p1 %patch086 -p1 +%patch087 -p1 diff --git a/_patch_order b/_patch_order index b3eb6ce..4d9b861 100644 --- a/_patch_order +++ b/_patch_order @@ -84,3 +84,4 @@ gdb-rhbz2024875-fix-unittest-failure.patch gdb-rhbz202487-rework-set-debuginfod.patch gdb-rhbz2024875-pr27026.patch gdb-rhbz2042257-ftbs-updates.patch +gdb-rhbz2042664-fix-sect_index_data-internal-error diff --git a/gdb-rhbz2042664-fix-sect_index_data-internal-error b/gdb-rhbz2042664-fix-sect_index_data-internal-error new file mode 100644 index 0000000..0a2a459 --- /dev/null +++ b/gdb-rhbz2042664-fix-sect_index_data-internal-error @@ -0,0 +1,128 @@ +From FEDORA_PATCHES Mon Sep 17 00:00:00 2001 +From: Kevin Buettner +Date: Tue, 1 Feb 2022 11:32:48 -0700 +Subject: gdb-rhbz2042664-fix-sect_index_data-internal-error + +;; Backport fix which fixes internal error due to libcc_s lacking a +;; .data section. + +Fix GDB internal error by using text (instead of data) section offset + +Fedora Rawhide is now using gcc-12.0. As part of updating to the +gcc-12.0 package set, Rawhide is also now using a version of libgcc_s +which lacks a .data section. This causes gdb to fail in the following +fashion while debugging a program (such as gdb) which uses libgcc_s: + + (top-gdb) run + Starting program: rawhide-master/bld/gdb/gdb + ... + objfiles.h:467: internal-error: sect_index_data not initialized + A problem internal to GDB has been detected, + further debugging may prove unreliable. + ... + +I snipped the backtrace from the above output. Instead, here's a +portion of a backtrace obtained using GDB's backtrace command. +(Obviously, in order to obtain it, I used a GDB which has been patched +with this commit.) + + #0 internal_error ( + file=0xc6a508 "gdb/objfiles.h", line=467, + fmt=0xc6a4e8 "sect_index_data not initialized") + at gdbsupport/errors.cc:51 + #1 0x00000000005f9651 in objfile::data_section_offset (this=0x4fa48f0) + at gdb/objfiles.h:467 + #2 0x000000000097c5f8 in relocate_address (address=0x17244, objfile=0x4fa48f0) + at gdb/stap-probe.c:1333 + #3 0x000000000097c630 in stap_probe::get_relocated_address (this=0xa1a17a0, + objfile=0x4fa48f0) + at gdb/stap-probe.c:1341 + #4 0x00000000004d7025 in create_exception_master_breakpoint_probe ( + objfile=0x4fa48f0) + at gdb/breakpoint.c:3505 + #5 0x00000000004d7426 in create_exception_master_breakpoint () + at gdb/breakpoint.c:3575 + #6 0x00000000004efcc1 in breakpoint_re_set () + at gdb/breakpoint.c:13407 + #7 0x0000000000956998 in solib_add (pattern=0x0, from_tty=0, readsyms=1) + at gdb/solib.c:1001 + #8 0x00000000009576a8 in handle_solib_event () + at gdb/solib.c:1269 + ... + +The function 'relocate_address' in gdb/stap-probe.c attempts to do +its "relocation" by using objfile->data_section_offset(). That +method, data_section_offset() is defined as follows in objfiles.h: + + CORE_ADDR data_section_offset () const + { + return section_offsets[SECT_OFF_DATA (this)]; + } + +The internal error occurs when the SECT_OFF_DATA macro finds that the +'sect_index_data' field is -1: + + #define SECT_OFF_DATA(objfile) \ + ((objfile->sect_index_data == -1) \ + ? (internal_error (__FILE__, __LINE__, \ + _("sect_index_data not initialized")), -1) \ + : objfile->sect_index_data) + +relocate_address() is obtaining the section offset in order to compute +a relocated address. For some ABIs, such as the System V ABI, the +section offsets will all be the same. So for those ABIs, it doesn't +matter which offset is used. However, other ABIs, such as the FDPIC +ABI, will have different offsets for the various sections. Thus, for +those ABIs, it is vital that this and other relocation code use the +correct offset. + +In stap_probe::get_relocated_address, the address to which to add the +offset (thus forming the relocated address) is obtained via +this->get_address (); get_address is a getter for m_address in +probe.h. It's documented/defined as follows (also in probe.h): + + /* The address where the probe is inserted, relative to + SECT_OFF_TEXT. */ + CORE_ADDR m_address; + +(Thanks to Tom Tromey for this observation.) + +So, based on this, the current use of data_section_offset / +SECT_OFF_DATA is wrong. This relocation code should have been using +text_section_offset / SECT_OFF_TEXT all along. That being the +case, I've adjusted the stap-probe.c relocation code accordingly. + +Searching the sources turned up one other use of data_section_offset, +in gdb/dtrace-probe.c, so I've updated that code as well. The same +reasoning presented above applies to this case too. + +Summary: + + * gdb/dtrace-probe.c (dtrace_probe::get_relocated_address): + Use method text_section_offset instead of data_section_offset. + * gdb/stap-probe.c (relocate_address): Likewise. + +diff --git a/gdb/dtrace-probe.c b/gdb/dtrace-probe.c +--- a/gdb/dtrace-probe.c ++++ b/gdb/dtrace-probe.c +@@ -684,7 +684,7 @@ dtrace_probe::is_enabled () const + CORE_ADDR + dtrace_probe::get_relocated_address (struct objfile *objfile) + { +- return this->get_address () + objfile->data_section_offset (); ++ return this->get_address () + objfile->text_section_offset (); + } + + /* Implementation of the get_argument_count method. */ +diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c +--- a/gdb/stap-probe.c ++++ b/gdb/stap-probe.c +@@ -1330,7 +1330,7 @@ stap_probe::parse_arguments (struct gdbarch *gdbarch) + static CORE_ADDR + relocate_address (CORE_ADDR address, struct objfile *objfile) + { +- return address + objfile->data_section_offset (); ++ return address + objfile->text_section_offset (); + } + + /* Implementation of the get_relocated_address method. */ diff --git a/gdb.spec b/gdb.spec index 6c8de94..26a7ef9 100644 --- a/gdb.spec +++ b/gdb.spec @@ -37,7 +37,7 @@ Version: 11.1 # 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: 11%{?dist} +Release: 12%{?dist} License: GPLv3+ and GPLv3+ with exceptions and GPLv2+ and GPLv2+ with exceptions and GPL+ and LGPLv2+ and LGPLv3+ and BSD and Public Domain and GFDL # Do not provide URL for snapshots as the file lasts there only for 2 days. @@ -1144,6 +1144,10 @@ fi %endif %changelog +* Mon Jan 31, 2022 Kevin Buettner - 11.1-12 +- Fix "sect_index_data not initialized" internal error. (RHBZ 2042664, + Kevin Buettner). + * Mon Jan 31 2022 Keith Seitz - 11.1-11 - Fix buld issues. (RHBZ 2042257, Keith Seitz, Andrew Burgess) - Update libipt to 2.0.5.