diff options
Diffstat (limited to 'libdw/dwarf_nextcu.c')
| -rw-r--r-- | libdw/dwarf_nextcu.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/libdw/dwarf_nextcu.c b/libdw/dwarf_nextcu.c index 30743022..3927c41e 100644 --- a/libdw/dwarf_nextcu.c +++ b/libdw/dwarf_nextcu.c @@ -53,6 +53,7 @@ #endif #include <libdwP.h> +#include <dwarf.h> int @@ -91,9 +92,9 @@ dwarf_nextcu (dwarf, off, next_off, header_sizep, abbrev_offsetp, of the .debug_info contribution for that compilation unit, not including the length field itself. In the 32-bit DWARF format, this is a 4-byte unsigned integer (which must be less than - 0xffffff00); in the 64-bit DWARF format, this consists of the + 0xfffffff0); in the 64-bit DWARF format, this consists of the 4-byte value 0xffffffff followed by an 8-byte unsigned integer - that gives the actual length (see Section 7.4). + that gives the actual length (see Section 7.2.2). 2. A 2-byte unsigned integer representing the version of the DWARF information for that compilation unit. For DWARF Version @@ -112,22 +113,27 @@ dwarf_nextcu (dwarf, off, next_off, header_sizep, abbrev_offsetp, offset portion of an address. */ uint64_t length = read_4ubyte_unaligned_inc (dwarf, bytes); size_t offset_size = 4; - if (length == 0xffffffffu) + /* Lengths of 0xfffffff0 - 0xffffffff are escape codes. Oxffffffff is + used to indicate that 64-bit dwarf information is being used, the + other values are currently reserved. */ + if (length == DWARF3_LENGTH_64_BIT) offset_size = 8; + else if (unlikely (length >= DWARF3_LENGTH_MIN_ESCAPE_CODE + && length <= DWARF3_LENGTH_MAX_ESCAPE_CODE)) + { + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return -1; + } - /* Now we know how large the header is. Note the trick in the - computation. If the offset_size is 4 the '- 4' term undoes the - '2 *'. If offset_size is 8 this term computes the size of the - escape value plus the 8 byte offset. */ - if (unlikely (off + 2 * offset_size - 4 + sizeof (uint16_t) - + offset_size + sizeof (uint8_t) + /* Now we know how large the header is. */ + if (unlikely (DIE_OFFSET_FROM_CU_OFFSET (off, offset_size) >= dwarf->sectiondata[IDX_debug_info]->d_size)) { *next_off = -1; return 1; } - if (length == 0xffffffffu) + if (length == DWARF3_LENGTH_64_BIT) /* This is a 64-bit DWARF format. */ length = read_8ubyte_unaligned_inc (dwarf, bytes); @@ -160,7 +166,8 @@ dwarf_nextcu (dwarf, off, next_off, header_sizep, abbrev_offsetp, - ((char *) dwarf->sectiondata[IDX_debug_info]->d_buf + off)); - /* See above for an explanation of the trick in this formula. */ + /* See definition of DIE_OFFSET_FROM_CU_OFFSET macro + for an explanation of the trick in this expression. */ *next_off = off + 2 * offset_size - 4 + length; return 0; |