diff options
Diffstat (limited to 'libdwfl/dwfl_segment_report_module.c')
| -rw-r--r-- | libdwfl/dwfl_segment_report_module.c | 49 |
1 files changed, 35 insertions, 14 deletions
diff --git a/libdwfl/dwfl_segment_report_module.c b/libdwfl/dwfl_segment_report_module.c index 5125decf..d2b43d3b 100644 --- a/libdwfl/dwfl_segment_report_module.c +++ b/libdwfl/dwfl_segment_report_module.c @@ -1,5 +1,5 @@ /* Sniff out modules from ELF headers visible in memory segments. - Copyright (C) 2008-2012, 2014, 2015 Red Hat, Inc. + Copyright (C) 2008-2012, 2014, 2015, 2018 Red Hat, Inc. This file is part of elfutils. This file is free software; you can redistribute it and/or modify @@ -27,7 +27,7 @@ not, see <http://www.gnu.org/licenses/>. */ #include <config.h> -#include "../libelf/libelfP.h" /* For NOTE_ALIGN. */ +#include "../libelf/libelfP.h" /* For NOTE_ALIGN4 and NOTE_ALIGN8. */ #undef _ #include "libdwflP.h" #include "common.h" @@ -301,7 +301,10 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, inline bool read_portion (void **data, size_t *data_size, GElf_Addr vaddr, size_t filesz) { - if (vaddr - start + filesz > buffer_available + /* Check whether we will have to read the segment data, or if it + can be returned from the existing buffer. */ + if (filesz > buffer_available + || vaddr - start > buffer_available - filesz /* If we're in string mode, then don't consider the buffer we have sufficient unless it contains the terminator of the string. */ || (filesz == 0 && memchr (vaddr - start + buffer, '\0', @@ -448,7 +451,8 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, GElf_Addr build_id_vaddr = 0; /* Consider a PT_NOTE we've found in the image. */ - inline void consider_notes (GElf_Addr vaddr, GElf_Xword filesz) + inline void consider_notes (GElf_Addr vaddr, GElf_Xword filesz, + GElf_Xword align) { /* If we have already seen a build ID, we don't care any more. */ if (build_id != NULL || filesz == 0) @@ -459,6 +463,12 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, if (read_portion (&data, &data_size, vaddr, filesz)) return; + /* data_size will be zero if we got everything from the initial + buffer, otherwise it will be the size of the new buffer that + could be read. */ + if (data_size != 0) + filesz = data_size; + assert (sizeof (Elf32_Nhdr) == sizeof (Elf64_Nhdr)); void *notes; @@ -469,7 +479,8 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, notes = malloc (filesz); if (unlikely (notes == NULL)) return; - xlatefrom.d_type = xlateto.d_type = ELF_T_NHDR; + xlatefrom.d_type = xlateto.d_type = (align == 8 + ? ELF_T_NHDR8 : ELF_T_NHDR); xlatefrom.d_buf = (void *) data; xlatefrom.d_size = filesz; xlateto.d_buf = notes; @@ -480,15 +491,23 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, } const GElf_Nhdr *nh = notes; - while ((const void *) nh < (const void *) notes + filesz) - { - const void *note_name = nh + 1; - const void *note_desc = note_name + NOTE_ALIGN (nh->n_namesz); - if (unlikely ((size_t) ((const void *) notes + filesz - - note_desc) < nh->n_descsz)) + size_t len = 0; + while (filesz > len + sizeof (*nh)) + { + const void *note_name; + const void *note_desc; + + len += sizeof (*nh); + note_name = notes + len; + + len += nh->n_namesz; + len = align == 8 ? NOTE_ALIGN8 (len) : NOTE_ALIGN4 (len); + note_desc = notes + len; + + if (unlikely (filesz < len + nh->n_descsz)) break; - if (nh->n_type == NT_GNU_BUILD_ID + if (nh->n_type == NT_GNU_BUILD_ID && nh->n_descsz > 0 && nh->n_namesz == sizeof "GNU" && !memcmp (note_name, "GNU", sizeof "GNU")) @@ -501,7 +520,9 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, break; } - nh = note_desc + NOTE_ALIGN (nh->n_descsz); + len += nh->n_descsz; + len = align == 8 ? NOTE_ALIGN8 (len) : NOTE_ALIGN4 (len); + nh = (void *) notes + len; } done: @@ -526,7 +547,7 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, case PT_NOTE: /* We calculate from the p_offset of the note segment, because we don't yet know the bias for its p_vaddr. */ - consider_notes (start + offset, filesz); + consider_notes (start + offset, filesz, align); break; case PT_LOAD: |