diff options
Diffstat (limited to 'src/pal/src/libunwind/src/dwarf/Gfde.c')
| -rw-r--r-- | src/pal/src/libunwind/src/dwarf/Gfde.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/src/pal/src/libunwind/src/dwarf/Gfde.c b/src/pal/src/libunwind/src/dwarf/Gfde.c new file mode 100644 index 0000000000..9250b895ea --- /dev/null +++ b/src/pal/src/libunwind/src/dwarf/Gfde.c @@ -0,0 +1,359 @@ +/* libunwind - a platform-independent unwind library + Copyright (c) 2003-2005 Hewlett-Packard Development Company, L.P. + Contributed by David Mosberger-Tang <davidm@hpl.hp.com> + +This file is part of libunwind. + +Permission is hereby granted, free of charge, to any person obtaining +a copy of this software and associated documentation files (the +"Software"), to deal in the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +The above copyright notice and this permission notice shall be +included in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ + +#include "dwarf_i.h" + +static inline int +is_cie_id (unw_word_t val, int is_debug_frame) +{ + /* The CIE ID is normally 0xffffffff (for 32-bit ELF) or + 0xffffffffffffffff (for 64-bit ELF). However, .eh_frame + uses 0. */ + if (is_debug_frame) + return (val == (uint32_t)(-1) || val == (uint64_t)(-1)); + else + return (val == 0); +} + +/* Note: we don't need to keep track of more than the first four + characters of the augmentation string, because we (a) ignore any + augmentation string contents once we find an unrecognized character + and (b) those characters that we do recognize, can't be + repeated. */ +static inline int +parse_cie (unw_addr_space_t as, unw_accessors_t *a, unw_word_t addr, + const unw_proc_info_t *pi, struct dwarf_cie_info *dci, + int is_debug_frame, void *arg) +{ + uint8_t version, ch, augstr[5], fde_encoding, handler_encoding; + unw_word_t len, cie_end_addr, aug_size; + uint32_t u32val; + uint64_t u64val; + size_t i; + int ret; +# define STR2(x) #x +# define STR(x) STR2(x) + + /* Pick appropriate default for FDE-encoding. DWARF spec says + start-IP (initial_location) and the code-size (address_range) are + "address-unit sized constants". The `R' augmentation can be used + to override this, but by default, we pick an address-sized unit + for fde_encoding. */ + switch (dwarf_addr_size (as)) + { + case 4: fde_encoding = DW_EH_PE_udata4; break; + case 8: fde_encoding = DW_EH_PE_udata8; break; + default: fde_encoding = DW_EH_PE_omit; break; + } + + dci->lsda_encoding = DW_EH_PE_omit; + dci->handler = 0; + + if ((ret = dwarf_readu32 (as, a, &addr, &u32val, arg)) < 0) + return ret; + + if (u32val != 0xffffffff) + { + /* the CIE is in the 32-bit DWARF format */ + uint32_t cie_id; + /* DWARF says CIE id should be 0xffffffff, but in .eh_frame, it's 0 */ + const uint32_t expected_id = (is_debug_frame) ? 0xffffffff : 0; + + len = u32val; + cie_end_addr = addr + len; + if ((ret = dwarf_readu32 (as, a, &addr, &cie_id, arg)) < 0) + return ret; + if (cie_id != expected_id) + { + Debug (1, "Unexpected CIE id %x\n", cie_id); + return -UNW_EINVAL; + } + } + else + { + /* the CIE is in the 64-bit DWARF format */ + uint64_t cie_id; + /* DWARF says CIE id should be 0xffffffffffffffff, but in + .eh_frame, it's 0 */ + const uint64_t expected_id = (is_debug_frame) ? 0xffffffffffffffffull : 0; + + if ((ret = dwarf_readu64 (as, a, &addr, &u64val, arg)) < 0) + return ret; + len = u64val; + cie_end_addr = addr + len; + if ((ret = dwarf_readu64 (as, a, &addr, &cie_id, arg)) < 0) + return ret; + if (cie_id != expected_id) + { + Debug (1, "Unexpected CIE id %llx\n", (long long) cie_id); + return -UNW_EINVAL; + } + } + dci->cie_instr_end = cie_end_addr; + + if ((ret = dwarf_readu8 (as, a, &addr, &version, arg)) < 0) + return ret; + + /* GCC emits version 1??? */ + if (version != 1 && (version < DWARF_CIE_VERSION || version > DWARF_CIE_VERSION_MAX)) + { + Debug (1, "Got CIE version %u, expected version 1 or between " + STR (DWARF_CIE_VERSION) " and " STR (DWARF_CIE_VERSION_MAX) "\n", version); + return -UNW_EBADVERSION; + } + + /* read and parse the augmentation string: */ + memset (augstr, 0, sizeof (augstr)); + for (i = 0;;) + { + if ((ret = dwarf_readu8 (as, a, &addr, &ch, arg)) < 0) + return ret; + + if (!ch) + break; /* end of augmentation string */ + + if (i < sizeof (augstr) - 1) + augstr[i++] = ch; + } + + if ((ret = dwarf_read_uleb128 (as, a, &addr, &dci->code_align, arg)) < 0 + || (ret = dwarf_read_sleb128 (as, a, &addr, &dci->data_align, arg)) < 0) + return ret; + + /* Read the return-address column either as a u8 or as a uleb128. */ + if (version == 1) + { + if ((ret = dwarf_readu8 (as, a, &addr, &ch, arg)) < 0) + return ret; + dci->ret_addr_column = ch; + } + else if ((ret = dwarf_read_uleb128 (as, a, &addr, &dci->ret_addr_column, + arg)) < 0) + return ret; + + i = 0; + if (augstr[0] == 'z') + { + dci->sized_augmentation = 1; + if ((ret = dwarf_read_uleb128 (as, a, &addr, &aug_size, arg)) < 0) + return ret; + i++; + } + + for (; i < sizeof (augstr) && augstr[i]; ++i) + switch (augstr[i]) + { + case 'L': + /* read the LSDA pointer-encoding format. */ + if ((ret = dwarf_readu8 (as, a, &addr, &ch, arg)) < 0) + return ret; + dci->lsda_encoding = ch; + break; + + case 'R': + /* read the FDE pointer-encoding format. */ + if ((ret = dwarf_readu8 (as, a, &addr, &fde_encoding, arg)) < 0) + return ret; + break; + + case 'P': + /* read the personality-routine pointer-encoding format. */ + if ((ret = dwarf_readu8 (as, a, &addr, &handler_encoding, arg)) < 0) + return ret; + if ((ret = dwarf_read_encoded_pointer (as, a, &addr, handler_encoding, + pi, &dci->handler, arg)) < 0) + return ret; + break; + + case 'S': + /* This is a signal frame. */ + dci->signal_frame = 1; + + /* Temporarily set it to one so dwarf_parse_fde() knows that + it should fetch the actual ABI/TAG pair from the FDE. */ + dci->have_abi_marker = 1; + break; + + default: + Debug (1, "Unexpected augmentation string `%s'\n", augstr); + if (dci->sized_augmentation) + /* If we have the size of the augmentation body, we can skip + over the parts that we don't understand, so we're OK. */ + goto done; + else + return -UNW_EINVAL; + } + done: + dci->fde_encoding = fde_encoding; + dci->cie_instr_start = addr; + Debug (15, "CIE parsed OK, augmentation = \"%s\", handler=0x%lx\n", + augstr, (long) dci->handler); + return 0; +} + +/* Extract proc-info from the FDE starting at adress ADDR. + + Pass BASE as zero for eh_frame behaviour, or a pointer to + debug_frame base for debug_frame behaviour. */ + +HIDDEN int +dwarf_extract_proc_info_from_fde (unw_addr_space_t as, unw_accessors_t *a, + unw_word_t *addrp, unw_proc_info_t *pi, + unw_word_t base, + int need_unwind_info, int is_debug_frame, + void *arg) +{ + unw_word_t fde_end_addr, cie_addr, cie_offset_addr, aug_end_addr = 0; + unw_word_t start_ip, ip_range, aug_size, addr = *addrp; + int ret, ip_range_encoding; + struct dwarf_cie_info dci; + uint64_t u64val; + uint32_t u32val; + + Debug (12, "FDE @ 0x%lx\n", (long) addr); + + memset (&dci, 0, sizeof (dci)); + + if ((ret = dwarf_readu32 (as, a, &addr, &u32val, arg)) < 0) + return ret; + + if (u32val != 0xffffffff) + { + int32_t cie_offset = 0; + + /* In some configurations, an FDE with a 0 length indicates the + end of the FDE-table. */ + if (u32val == 0) + return -UNW_ENOINFO; + + /* the FDE is in the 32-bit DWARF format */ + + *addrp = fde_end_addr = addr + u32val; + cie_offset_addr = addr; + + if ((ret = dwarf_reads32 (as, a, &addr, &cie_offset, arg)) < 0) + return ret; + + if (is_cie_id (cie_offset, is_debug_frame)) + /* ignore CIEs (happens during linear searches) */ + return 0; + + if (is_debug_frame) + cie_addr = base + cie_offset; + else + /* DWARF says that the CIE_pointer in the FDE is a + .debug_frame-relative offset, but the GCC-generated .eh_frame + sections instead store a "pcrelative" offset, which is just + as fine as it's self-contained. */ + cie_addr = cie_offset_addr - cie_offset; + } + else + { + int64_t cie_offset = 0; + + /* the FDE is in the 64-bit DWARF format */ + + if ((ret = dwarf_readu64 (as, a, &addr, &u64val, arg)) < 0) + return ret; + + *addrp = fde_end_addr = addr + u64val; + cie_offset_addr = addr; + + if ((ret = dwarf_reads64 (as, a, &addr, &cie_offset, arg)) < 0) + return ret; + + if (is_cie_id (cie_offset, is_debug_frame)) + /* ignore CIEs (happens during linear searches) */ + return 0; + + if (is_debug_frame) + cie_addr = base + cie_offset; + else + /* DWARF says that the CIE_pointer in the FDE is a + .debug_frame-relative offset, but the GCC-generated .eh_frame + sections instead store a "pcrelative" offset, which is just + as fine as it's self-contained. */ + cie_addr = (unw_word_t) ((uint64_t) cie_offset_addr - cie_offset); + } + + Debug (15, "looking for CIE at address %lx\n", (long) cie_addr); + + if ((ret = parse_cie (as, a, cie_addr, pi, &dci, is_debug_frame, arg)) < 0) + return ret; + + /* IP-range has same encoding as FDE pointers, except that it's + always an absolute value: */ + ip_range_encoding = dci.fde_encoding & DW_EH_PE_FORMAT_MASK; + + if ((ret = dwarf_read_encoded_pointer (as, a, &addr, dci.fde_encoding, + pi, &start_ip, arg)) < 0 + || (ret = dwarf_read_encoded_pointer (as, a, &addr, ip_range_encoding, + pi, &ip_range, arg)) < 0) + return ret; + pi->start_ip = start_ip; + pi->end_ip = start_ip + ip_range; + pi->handler = dci.handler; + + if (dci.sized_augmentation) + { + if ((ret = dwarf_read_uleb128 (as, a, &addr, &aug_size, arg)) < 0) + return ret; + aug_end_addr = addr + aug_size; + } + + if ((ret = dwarf_read_encoded_pointer (as, a, &addr, dci.lsda_encoding, + pi, &pi->lsda, arg)) < 0) + return ret; + + Debug (15, "FDE covers IP 0x%lx-0x%lx, LSDA=0x%lx\n", + (long) pi->start_ip, (long) pi->end_ip, (long) pi->lsda); + + if (need_unwind_info) + { + pi->format = UNW_INFO_FORMAT_TABLE; + pi->unwind_info_size = sizeof (dci); + pi->unwind_info = mempool_alloc (&dwarf_cie_info_pool); + if (!pi->unwind_info) + return -UNW_ENOMEM; + + if (dci.have_abi_marker) + { + if ((ret = dwarf_readu16 (as, a, &addr, &dci.abi, arg)) < 0 + || (ret = dwarf_readu16 (as, a, &addr, &dci.tag, arg)) < 0) + return ret; + Debug (13, "Found ABI marker = (abi=%u, tag=%u)\n", + dci.abi, dci.tag); + } + + if (dci.sized_augmentation) + dci.fde_instr_start = aug_end_addr; + else + dci.fde_instr_start = addr; + dci.fde_instr_end = fde_end_addr; + + memcpy (pi->unwind_info, &dci, sizeof (dci)); + } + return 0; +} |