From c38e85596e435e83efa054b2d069ebb20dd9525e Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Fri, 7 Mar 2014 12:11:40 +0000 Subject: [PATCH] AIX 32-bit core loading, high section addresses. I noticed GDB was failing to enable threading support for 32-bit AIX cores. I traced it to failure to read variables from libpthreads.a. The issue is that data for that library is loaded at a high address, and bfd is sign extending the section addresses: (gdb) info files Symbols from "/home/palves/crash". Local core dump file: `/home/palves/core', file type aixcoff-rs6000. 0x2ff22000 - 0x2ff23000 is .stack 0x20000000 - 0x200316e0 is .data 0x20000e90 - 0x200016c0 is .data 0xfffffffff0254000 - 0xfffffffff0297920 is .data 0xfffffffff07b46a8 - 0xfffffffff07b47c8 is .data 0xfffffffff0298000 - 0xfffffffff029bfcc is .data 0xfffffffff06dafe0 - 0xfffffffff07b3838 is .data Local exec file: `/home/palves/crash', file type aixcoff-rs6000. Entry point: 0x20001394 0x10000150 - 0x10000e90 is .text 0x20000e90 - 0x2000149c is .data 0x2000149c - 0x200016c0 is .bss 0xd053b124 - 0xd053e15f is .text in /usr/lib/libpthreads.a(shr_comm.o) 0xf0254000 - 0xf0297920 is .data in /usr/lib/libpthreads.a(shr_comm.o) 0xf0254450 - 0xf0297920 is .bss in /usr/lib/libpthreads.a(shr_comm.o) 0xd053a280 - 0xd053aabe is .text in /usr/lib/libcrypt.a(shr.o) 0xf07b46a8 - 0xf07b47c8 is .data in /usr/lib/libcrypt.a(shr.o) 0xf07b47c8 - 0xf07b47c8 is .bss in /usr/lib/libcrypt.a(shr.o) 0xd04fb180 - 0xd053917e is .text in /usr/lib/libpthreads.a(shr_xpg5.o) 0xf0298000 - 0xf029bfcc is .data in /usr/lib/libpthreads.a(shr_xpg5.o) 0xf029bf64 - 0xf029bfcc is .bss in /usr/lib/libpthreads.a(shr_xpg5.o) 0xd0100900 - 0xd04fa39c is .text in /usr/lib/libc.a(shr.o) 0xf06dafe0 - 0xf07b3838 is .data in /usr/lib/libc.a(shr.o) 0xf0751e94 - 0xf07b3838 is .bss in /usr/lib/libc.a(shr.o) Notice: ... 0xfffffffff0298000 - 0xfffffffff029bfcc is .data ... Those are the bfd section start/end addresses. It't not visible here: ... 0xf0298000 - 0xf029bfcc is .data in /usr/lib/libpthreads.a(shr_xpg5.o) ... ... just because GDB trims that number to 32-bit when printing. GDB then fails to find the memory for libpthreads.a variables in the core, and falls back to reading it directly from the executable (which yields the values as originally initialized in the code). E.g.: (gdb) p &__n_pthreads $2 = ( *) 0xf074fda8 <__n_pthreads> (gdb) p __n_pthreads $1 = -1 That should have returned 2 instead of -1. bfd/ 2014-03-07 Pedro Alves * rs6000-core.c (rs6000coff_core_p): Cast pointers to bfd_vma through ptr_to_uint instead of through long. --- bfd/ChangeLog | 5 +++++ bfd/rs6000-core.c | 4 ++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 253e061..5f2bdb2 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,8 @@ +2014-03-07 Pedro Alves + + * rs6000-core.c (rs6000coff_core_p): Cast pointers to bfd_vma + through ptr_to_uint instead of through long. + 2014-03-06 Nick Clifton PR 16664 diff --git a/bfd/rs6000-core.c b/bfd/rs6000-core.c index afc81cb..8f2f3a0 100644 --- a/bfd/rs6000-core.c +++ b/bfd/rs6000-core.c @@ -583,7 +583,7 @@ rs6000coff_core_p (bfd *abfd) { ldi_core = ldinfo.l32.ldinfo_core; ldi_datasize = ldinfo.l32.ldinfo_datasize; - ldi_dataorg = (bfd_vma) (long) ldinfo.l32.ldinfo_dataorg; + ldi_dataorg = (bfd_vma) (ptr_to_uint) ldinfo.l32.ldinfo_dataorg; ldi_next = ldinfo.l32.ldinfo_next; } @@ -625,7 +625,7 @@ rs6000coff_core_p (bfd *abfd) } else { - vminfo_addr = (bfd_vma) (long) vminfo.old.vminfo_addr; + vminfo_addr = (bfd_vma) (ptr_to_uint) vminfo.old.vminfo_addr; vminfo_size = vminfo.old.vminfo_size; vminfo_offset = vminfo.old.vminfo_offset; } -- 2.7.4