libdd-libunwind-sys 1.0.2

Rust bindings for using unwind library inside libdatadog
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/* Copyright (C) 2022 Hewlett-Packard Co.
     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 <stddef.h>
#include "libunwind_i.h"
#include "dwarf-eh.h"
#include "dwarf_i.h"

int
unw_get_proc_info_in_range (unw_word_t        start_ip,
							unw_word_t        end_ip,
                            unw_word_t        eh_frame_table,
                            unw_word_t        eh_frame_table_len UNUSED,
                            unw_word_t        exidx_frame_table UNUSED,
                            unw_word_t        exidx_frame_table_len UNUSED,
                            unw_addr_space_t  as,
                            unw_word_t        ip,
                            unw_proc_info_t  *pi,
                            int               need_unwind_info,
                            void             *arg)
{
    int ret = 0;

    unw_dyn_info_t di;
    memset(&di, 0, sizeof(di));

    di.start_ip = start_ip;
    di.end_ip = end_ip;
    di.gp = pi->gp;
    di.u.rti.name_ptr = 0;

#if UNW_TARGET_ARM
    if (exidx_frame_table != 0) {
        di.format = UNW_INFO_FORMAT_ARM_EXIDX;
        di.u.rti.table_data = exidx_frame_table;
        di.u.rti.table_len = exidx_frame_table_len;
        di.u.rti.segbase = 0;
    }
    else
#endif
    if (eh_frame_table != 0) {
        unw_accessors_t *a = unw_get_accessors_int (as);

        unw_word_t data;
        if ((*a->access_mem)(as, eh_frame_table, &data, 0, arg) < 0) {
            return -UNW_EINVAL;
        }
        /* we are reading only the first 4 `char` members of `struct dwarf_eh_frame_hdr`, which
         * are guaranteed to fit into the first `sizeof(unw_word_t)` bytes */
        struct dwarf_eh_frame_hdr exhdr;
        memcpy(&exhdr, &data, sizeof(data));

        if (exhdr.version != DW_EH_VERSION) {
            Debug (1, "Unexpected version %d\n", exhdr.version);
            return -UNW_EBADVERSION;
        }
        unw_word_t addr = eh_frame_table + offsetof(struct dwarf_eh_frame_hdr, eh_frame);
        unw_word_t eh_frame_start;
        unw_word_t fde_count;

        /* read eh_frame_ptr */
        if ((ret = dwarf_read_encoded_pointer(as, a, &addr, exhdr.eh_frame_ptr_enc, pi, &eh_frame_start, arg)) < 0) {
            return ret;
        }

        /* read fde_count */
        if ((ret = dwarf_read_encoded_pointer(as, a, &addr, exhdr.fde_count_enc, pi, &fde_count, arg)) < 0) {
            return ret;
        }

        // If there are no frame table entries
        if (fde_count == 0) {
            Debug(1, "No frame table entries\n");
            return -UNW_ENOINFO;
        }

        if (exhdr.table_enc != (DW_EH_PE_datarel | DW_EH_PE_sdata4)) {
            Debug (1, "Table encoding not supported %x\n", exhdr.table_enc);
            return -UNW_EINVAL;
        }

        di.format = UNW_INFO_FORMAT_REMOTE_TABLE;
        di.u.rti.table_data = addr;
        di.u.rti.table_len = (fde_count * 8) / sizeof (unw_word_t);
        di.u.rti.segbase = eh_frame_table;
    }
    else {
        Debug (1, "No frame table data\n");
        return -UNW_ENOINFO;
    }

    ret = tdep_search_unwind_table(as, ip, &di, pi, need_unwind_info, arg);
    if (ret < 0) {
        return ret;
    }

    if (ip < pi->start_ip || ip >= pi->end_ip) {
        Debug (1, "ip %p not in range start_ip %p end_ip %p\n", ip, pi->start_ip, pi->end_ip);
        return -UNW_ENOINFO;
    }
    return UNW_ESUCCESS;
}