diff --git a/_gdb.spec.Patch.include b/_gdb.spec.Patch.include index a1230be..7e7ebd8 100644 --- a/_gdb.spec.Patch.include +++ b/_gdb.spec.Patch.include @@ -512,3 +512,8 @@ Patch123: gdb-find_and_open_source-empty-string-ub-3of4.patch # (Simon Marchi) Patch124: gdb-find_and_open_source-empty-string-ub-4of4.patch +# Backport "Fix GDB internal error by using text (instead of data) +# section offset" +# (Kevin Buettner, RHEL-107399) +Patch125: gdb-rhel-17399-sect_index_data-not-initialized.patch + diff --git a/_gdb.spec.patch.include b/_gdb.spec.patch.include index 97f12c4..bd3879e 100644 --- a/_gdb.spec.patch.include +++ b/_gdb.spec.patch.include @@ -122,3 +122,4 @@ %patch122 -p1 %patch123 -p1 %patch124 -p1 +%patch125 -p1 diff --git a/_patch_order b/_patch_order index a61349b..593fd43 100644 --- a/_patch_order +++ b/_patch_order @@ -122,3 +122,4 @@ gdb-find_and_open_source-empty-string-ub-1of4.patch gdb-find_and_open_source-empty-string-ub-2of4.patch gdb-find_and_open_source-empty-string-ub-3of4.patch gdb-find_and_open_source-empty-string-ub-4of4.patch +gdb-rhel-17399-sect_index_data-not-initialized.patch diff --git a/gdb-rhel-17399-sect_index_data-not-initialized.patch b/gdb-rhel-17399-sect_index_data-not-initialized.patch new file mode 100644 index 0000000..aefdb75 --- /dev/null +++ b/gdb-rhel-17399-sect_index_data-not-initialized.patch @@ -0,0 +1,127 @@ +From FEDORA_PATCHES Mon Sep 17 00:00:00 2001 +From: Kevin Buettner +Date: Tue, 25 Jan 2022 14:45:16 -0700 +Subject: gdb-rhel-17399-sect_index_data-not-initialized.patch + +;; Backport "Fix GDB internal error by using text (instead of data) +;; section offset" +;; (Kevin Buettner, RHEL-107399) + +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 +@@ -685,7 +685,7 @@ 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 +@@ -1290,7 +1290,7 @@ 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 f307aa6..6184f57 100644 --- a/gdb.spec +++ b/gdb.spec @@ -1158,6 +1158,11 @@ fi %endif %changelog +* Thu Apr 11 2024 Keith Seitz +- Backport "Fix GDB internal error by using text (instead of data) + section offset" + (Kevin Buettner, RHEL-17399) + * Wed Dec 13 2023 Keith Seitz - 10.2-13.el9 - Backport patches for "Fix undefined behaviour dereferencing empty string" (Magne Hov et al, RHEL-17631)