diff options
| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | libdwfl/ChangeLog | 7 | ||||
| -rw-r--r-- | libdwfl/libdwfl.h | 20 | ||||
| -rw-r--r-- | libdwfl/libdwflP.h | 7 | ||||
| -rw-r--r-- | libdwfl/segment.c | 35 | ||||
| -rw-r--r-- | tests/ChangeLog | 5 | ||||
| -rw-r--r-- | tests/Makefile.am | 6 | ||||
| -rw-r--r-- | tests/dwfl-report-segment-contiguous.c | 82 |
8 files changed, 118 insertions, 45 deletions
@@ -112,6 +112,7 @@ Makefile.in /tests/dwfl-bug-report /tests/dwfl-proc-attach /tests/dwfl-report-elf-align +/tests/dwfl-report-segment-contiguous /tests/dwfllines /tests/dwflmodtest /tests/dwflsyms diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index b6b427d4..b36a7ca6 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,10 @@ +2019-12-11 Omar Sandoval <osandov@fb.com> + + * libdwflP.h (Dwfl_Module): Remove coalescing state. + Rename lookup_tail_ndx to next_segndx. + * segment.c (dwfl_report_segment): Remove coalescing logic. + * libdwfl.h (dwfl_report_segment): Document that IDENT is ignored. + 2019-12-05 Mark Wielaard <mark@klomp.org> * linux-kernel-modules.c (find_kernel_elf): Also try to find diff --git a/libdwfl/libdwfl.h b/libdwfl/libdwfl.h index a0c1d357..d5fa06d4 100644 --- a/libdwfl/libdwfl.h +++ b/libdwfl/libdwfl.h @@ -111,7 +111,7 @@ extern void dwfl_report_begin (Dwfl *dwfl); /* Report that segment NDX begins at PHDR->p_vaddr + BIAS. If NDX is < 0, the value succeeding the last call's NDX - is used instead (zero on the first call). + is used instead (zero on the first call). IDENT is ignored. If nonzero, the smallest PHDR->p_align value seen sets the effective page size for the address space DWFL describes. @@ -120,21 +120,9 @@ extern void dwfl_report_begin (Dwfl *dwfl); Returns -1 for errors, or NDX (or its assigned replacement) on success. - When NDX is the value succeeding the last call's NDX (or is implicitly - so as above), IDENT is nonnull and matches the value in the last call, - and the PHDR and BIAS values reflect a segment that would be contiguous, - in both memory and file, with the last segment reported, then this - segment may be coalesced internally with preceding segments. When given - an address inside this segment, dwfl_addrsegment may return the NDX of a - preceding contiguous segment. To prevent coalesced segments, always - pass a null pointer for IDENT. - - The values passed are not stored (except to track coalescence). - The only information that can be extracted from DWFL later is the - mapping of an address to a segment index that starts at or below - it. Reporting segments at all is optional. Its only benefit to - the caller is to offer this quick lookup via dwfl_addrsegment, - or use other segment-based calls. */ + Reporting segments at all is optional. Its only benefit to the caller is to + offer this quick lookup via dwfl_addrsegment, or use other segment-based + calls. */ extern int dwfl_report_segment (Dwfl *dwfl, int ndx, const GElf_Phdr *phdr, GElf_Addr bias, const void *ident); diff --git a/libdwfl/libdwflP.h b/libdwfl/libdwflP.h index f631f946..25753de2 100644 --- a/libdwfl/libdwflP.h +++ b/libdwfl/libdwflP.h @@ -132,12 +132,7 @@ struct Dwfl GElf_Addr *lookup_addr; /* Start address of segment. */ Dwfl_Module **lookup_module; /* Module associated with segment, or null. */ int *lookup_segndx; /* User segment index, or -1. */ - - /* Cache from last dwfl_report_segment call. */ - const void *lookup_tail_ident; - GElf_Off lookup_tail_vaddr; - GElf_Off lookup_tail_offset; - int lookup_tail_ndx; + int next_segndx; struct Dwfl_User_Core *user_core; }; diff --git a/libdwfl/segment.c b/libdwfl/segment.c index d9599a7f..f6a3e84e 100644 --- a/libdwfl/segment.c +++ b/libdwfl/segment.c @@ -287,11 +287,15 @@ int dwfl_report_segment (Dwfl *dwfl, int ndx, const GElf_Phdr *phdr, GElf_Addr bias, const void *ident) { + /* This was previously used for coalescing segments, but it was buggy since + day one. We don't use it anymore. */ + (void)ident; + if (dwfl == NULL) return -1; if (ndx < 0) - ndx = dwfl->lookup_tail_ndx; + ndx = dwfl->next_segndx; if (phdr->p_align > 1 && (dwfl->segment_align <= 1 || phdr->p_align < dwfl->segment_align)) @@ -307,30 +311,19 @@ dwfl_report_segment (Dwfl *dwfl, int ndx, const GElf_Phdr *phdr, GElf_Addr bias, GElf_Addr end = __libdwfl_segment_end (dwfl, bias + phdr->p_vaddr + phdr->p_memsz); - /* Coalesce into the last one if contiguous and matching. */ - if (ndx != dwfl->lookup_tail_ndx - || ident == NULL - || ident != dwfl->lookup_tail_ident - || start != dwfl->lookup_tail_vaddr - || phdr->p_offset != dwfl->lookup_tail_offset) - { - /* Normally just appending keeps us sorted. */ + /* Normally just appending keeps us sorted. */ - size_t i = dwfl->lookup_elts; - while (i > 0 && unlikely (start < dwfl->lookup_addr[i - 1])) - --i; + size_t i = dwfl->lookup_elts; + while (i > 0 && unlikely (start < dwfl->lookup_addr[i - 1])) + --i; - if (unlikely (insert (dwfl, i, start, end, ndx))) - { - __libdwfl_seterrno (DWFL_E_NOMEM); - return -1; - } + if (unlikely (insert (dwfl, i, start, end, ndx))) + { + __libdwfl_seterrno (DWFL_E_NOMEM); + return -1; } - dwfl->lookup_tail_ident = ident; - dwfl->lookup_tail_vaddr = end; - dwfl->lookup_tail_offset = end - bias - phdr->p_vaddr + phdr->p_offset; - dwfl->lookup_tail_ndx = ndx + 1; + dwfl->next_segndx = ndx + 1; return ndx; } diff --git a/tests/ChangeLog b/tests/ChangeLog index ce67ce55..30bd8256 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -1,3 +1,8 @@ +2019-12-11 Omar Sandoval <osandov@fb.com> + + * dwfl-report-segment-coalesce.c: New test. + * Makefile.am: Add dwfl-report-segment-coalesce + 2019-12-06 Mark Wielaard <mark@klomp.org> * run-debuginfod-find.sh: Force -Wl,--build-id. diff --git a/tests/Makefile.am b/tests/Makefile.am index eab4ae6f..2c3ac299 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -50,7 +50,8 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \ test-flag-nobits dwarf-getstring rerequest_tag \ alldts typeiter typeiter2 low_high_pc \ test-elf_cntl_gelf_getshdr dwflsyms dwfllines \ - dwfl-report-elf-align varlocs backtrace backtrace-child \ + dwfl-report-elf-align dwfl-report-segment-contiguous \ + varlocs backtrace backtrace-child \ backtrace-data backtrace-dwarf debuglink debugaltlink \ buildid deleted deleted-lib.so aggregate_size peel_type \ vdsosyms \ @@ -113,7 +114,7 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile test-nlist \ run-native-test.sh run-bug1-test.sh \ run-debuglink.sh run-debugaltlink.sh run-buildid.sh \ dwfl-bug-addr-overflow run-addrname-test.sh \ - dwfl-bug-fd-leak dwfl-bug-report \ + dwfl-bug-fd-leak dwfl-bug-report dwfl-report-segment-contiguous \ run-dwfl-bug-offline-rel.sh run-dwfl-addr-sect.sh \ run-disasm-x86.sh run-disasm-x86-64.sh \ run-early-offscn.sh run-dwarf-getmacros.sh run-dwarf-ranges.sh \ @@ -589,6 +590,7 @@ test_elf_cntl_gelf_getshdr_LDADD = $(libelf) dwflsyms_LDADD = $(libdw) $(libelf) $(argp_LDADD) dwfllines_LDADD = $(libdw) $(libelf) $(argp_LDADD) dwfl_report_elf_align_LDADD = $(libdw) +dwfl_report_segment_contiguous_LDADD = $(libdw) $(libebl) $(libelf) varlocs_LDADD = $(libdw) $(libelf) $(argp_LDADD) backtrace_LDADD = $(libdw) $(libelf) $(argp_LDADD) # backtrace-child-biarch also uses those *_CFLAGS and *_LDLAGS variables: diff --git a/tests/dwfl-report-segment-contiguous.c b/tests/dwfl-report-segment-contiguous.c new file mode 100644 index 00000000..61e6bfee --- /dev/null +++ b/tests/dwfl-report-segment-contiguous.c @@ -0,0 +1,82 @@ +/* Test bug in dwfl_report_segment() coalescing. + Copyright (C) 2019 Facebook + This file is part of elfutils. + + This file is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + elfutils is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <config.h> +#include <assert.h> +#include <inttypes.h> +#include <stdio.h> +#include <stdio_ext.h> +#include <locale.h> +#include ELFUTILS_HEADER(dwfl) + + +static const Dwfl_Callbacks offline_callbacks = + { + .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo), + .section_address = INTUSE(dwfl_offline_section_address), + }; + + +int +main (void) +{ + /* We use no threads here which can interfere with handling a stream. */ + (void) __fsetlocking (stdout, FSETLOCKING_BYCALLER); + + /* Set locale. */ + (void) setlocale (LC_ALL, ""); + + Dwfl *dwfl = dwfl_begin (&offline_callbacks); + assert (dwfl != NULL); + + GElf_Phdr phdr1 = + { + .p_type = PT_LOAD, + .p_flags = PF_R, + .p_offset = 0xf00, + .p_vaddr = 0xf00, + .p_filesz = 0x100, + .p_memsz = 0x100, + .p_align = 4, + }; + + int ndx = dwfl_report_segment (dwfl, 1, &phdr1, 0, dwfl); + assert(ndx == 1); + + ndx = dwfl_addrsegment (dwfl, 0xf00, NULL); + assert(ndx == 1); + + GElf_Phdr phdr2 = + { + .p_type = PT_LOAD, + .p_flags = PF_R | PF_W, + .p_offset = 0x1000, + .p_vaddr = 0x1000, + .p_filesz = 0x100, + .p_memsz = 0x100, + .p_align = 4, + }; + ndx = dwfl_report_segment (dwfl, 2, &phdr2, 0, dwfl); + assert(ndx == 2); + + ndx = dwfl_addrsegment (dwfl, 0x1000, NULL); + assert(ndx == 1 || ndx == 2); + + dwfl_end (dwfl); + + return 0; +} |