7f08176ee8
thread specific informations. In order to do that, and in order to avoid KBI breakage with existing infrastructure the following semantic is implemented: - For live programs, a new member to the PT_LWPINFO is added (pl_tdname) - For cores, a new ELF note is added (NT_THRMISC) that can be used for storing thread specific, miscellaneous, informations. Right now it is just popluated with a thread name. GDB, then, retrieves the correct informations from the corefile via the BFD interface, as it groks the ELF notes and create appropriate pseudo-sections. Sponsored by: Sandvine Incorporated Tested by: gianni Discussed with: dim, kan, kib MFC after: 2 weeks
535 lines
14 KiB
C
535 lines
14 KiB
C
/*-
|
|
* Copyright (c) 2007 Sandvine Incorporated
|
|
* Copyright (c) 1998 John D. Polstra
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/procfs.h>
|
|
#include <sys/ptrace.h>
|
|
#include <sys/queue.h>
|
|
#include <sys/linker_set.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/user.h>
|
|
#include <sys/wait.h>
|
|
#include <machine/elf.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/vm.h>
|
|
#include <vm/pmap.h>
|
|
#include <vm/vm_map.h>
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <libutil.h>
|
|
|
|
#include "extern.h"
|
|
|
|
/*
|
|
* Code for generating ELF core dumps.
|
|
*/
|
|
|
|
typedef void (*segment_callback)(vm_map_entry_t, void *);
|
|
|
|
/* Closure for cb_put_phdr(). */
|
|
struct phdr_closure {
|
|
Elf_Phdr *phdr; /* Program header to fill in */
|
|
Elf_Off offset; /* Offset of segment in core file */
|
|
};
|
|
|
|
/* Closure for cb_size_segment(). */
|
|
struct sseg_closure {
|
|
int count; /* Count of writable segments. */
|
|
size_t size; /* Total size of all writable segments. */
|
|
};
|
|
|
|
static void cb_put_phdr(vm_map_entry_t, void *);
|
|
static void cb_size_segment(vm_map_entry_t, void *);
|
|
static void each_writable_segment(vm_map_entry_t, segment_callback,
|
|
void *closure);
|
|
static void elf_detach(void); /* atexit() handler. */
|
|
static void elf_puthdr(pid_t, vm_map_entry_t, void *, size_t *, int numsegs);
|
|
static void elf_putnote(void *dst, size_t *off, const char *name, int type,
|
|
const void *desc, size_t descsz);
|
|
static void freemap(vm_map_entry_t);
|
|
static vm_map_entry_t readmap(pid_t);
|
|
|
|
static pid_t g_pid; /* Pid being dumped, global for elf_detach */
|
|
|
|
static int
|
|
elf_ident(int efd, pid_t pid __unused, char *binfile __unused)
|
|
{
|
|
Elf_Ehdr hdr;
|
|
int cnt;
|
|
|
|
cnt = read(efd, &hdr, sizeof(hdr));
|
|
if (cnt != sizeof(hdr))
|
|
return (0);
|
|
if (IS_ELF(hdr))
|
|
return (1);
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
elf_detach(void)
|
|
{
|
|
|
|
if (g_pid != 0)
|
|
ptrace(PT_DETACH, g_pid, (caddr_t)1, 0);
|
|
}
|
|
|
|
/*
|
|
* Write an ELF coredump for the given pid to the given fd.
|
|
*/
|
|
static void
|
|
elf_coredump(int efd __unused, int fd, pid_t pid)
|
|
{
|
|
vm_map_entry_t map;
|
|
struct sseg_closure seginfo;
|
|
void *hdr;
|
|
size_t hdrsize;
|
|
Elf_Phdr *php;
|
|
int i;
|
|
|
|
/* Attach to process to dump. */
|
|
g_pid = pid;
|
|
if (atexit(elf_detach) != 0)
|
|
err(1, "atexit");
|
|
errno = 0;
|
|
ptrace(PT_ATTACH, pid, NULL, 0);
|
|
if (errno)
|
|
err(1, "PT_ATTACH");
|
|
if (waitpid(pid, NULL, 0) == -1)
|
|
err(1, "waitpid");
|
|
|
|
/* Get the program's memory map. */
|
|
map = readmap(pid);
|
|
|
|
/* Size the program segments. */
|
|
seginfo.count = 0;
|
|
seginfo.size = 0;
|
|
each_writable_segment(map, cb_size_segment, &seginfo);
|
|
|
|
/*
|
|
* Calculate the size of the core file header area by making
|
|
* a dry run of generating it. Nothing is written, but the
|
|
* size is calculated.
|
|
*/
|
|
hdrsize = 0;
|
|
elf_puthdr(pid, map, NULL, &hdrsize, seginfo.count);
|
|
|
|
/*
|
|
* Allocate memory for building the header, fill it up,
|
|
* and write it out.
|
|
*/
|
|
if ((hdr = calloc(1, hdrsize)) == NULL)
|
|
errx(1, "out of memory");
|
|
|
|
/* Fill in the header. */
|
|
hdrsize = 0;
|
|
elf_puthdr(pid, map, hdr, &hdrsize, seginfo.count);
|
|
|
|
/* Write it to the core file. */
|
|
if (write(fd, hdr, hdrsize) == -1)
|
|
err(1, "write");
|
|
|
|
/* Write the contents of all of the writable segments. */
|
|
php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
|
|
for (i = 0; i < seginfo.count; i++) {
|
|
struct ptrace_io_desc iorequest;
|
|
uintmax_t nleft = php->p_filesz;
|
|
|
|
iorequest.piod_op = PIOD_READ_D;
|
|
iorequest.piod_offs = (caddr_t)php->p_vaddr;
|
|
while (nleft > 0) {
|
|
char buf[8*1024];
|
|
size_t nwant;
|
|
ssize_t ngot;
|
|
|
|
if (nleft > sizeof(buf))
|
|
nwant = sizeof buf;
|
|
else
|
|
nwant = nleft;
|
|
iorequest.piod_addr = buf;
|
|
iorequest.piod_len = nwant;
|
|
ptrace(PT_IO, pid, (caddr_t)&iorequest, 0);
|
|
ngot = iorequest.piod_len;
|
|
if ((size_t)ngot < nwant)
|
|
errx(1, "short read wanted %d, got %d",
|
|
nwant, ngot);
|
|
ngot = write(fd, buf, nwant);
|
|
if (ngot == -1)
|
|
err(1, "write of segment %d failed", i);
|
|
if ((size_t)ngot != nwant)
|
|
errx(1, "short write");
|
|
nleft -= nwant;
|
|
iorequest.piod_offs += ngot;
|
|
}
|
|
php++;
|
|
}
|
|
free(hdr);
|
|
freemap(map);
|
|
}
|
|
|
|
/*
|
|
* A callback for each_writable_segment() to write out the segment's
|
|
* program header entry.
|
|
*/
|
|
static void
|
|
cb_put_phdr(vm_map_entry_t entry, void *closure)
|
|
{
|
|
struct phdr_closure *phc = (struct phdr_closure *)closure;
|
|
Elf_Phdr *phdr = phc->phdr;
|
|
|
|
phc->offset = round_page(phc->offset);
|
|
|
|
phdr->p_type = PT_LOAD;
|
|
phdr->p_offset = phc->offset;
|
|
phdr->p_vaddr = entry->start;
|
|
phdr->p_paddr = 0;
|
|
phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
|
|
phdr->p_align = PAGE_SIZE;
|
|
phdr->p_flags = 0;
|
|
if (entry->protection & VM_PROT_READ)
|
|
phdr->p_flags |= PF_R;
|
|
if (entry->protection & VM_PROT_WRITE)
|
|
phdr->p_flags |= PF_W;
|
|
if (entry->protection & VM_PROT_EXECUTE)
|
|
phdr->p_flags |= PF_X;
|
|
|
|
phc->offset += phdr->p_filesz;
|
|
phc->phdr++;
|
|
}
|
|
|
|
/*
|
|
* A callback for each_writable_segment() to gather information about
|
|
* the number of segments and their total size.
|
|
*/
|
|
static void
|
|
cb_size_segment(vm_map_entry_t entry, void *closure)
|
|
{
|
|
struct sseg_closure *ssc = (struct sseg_closure *)closure;
|
|
|
|
ssc->count++;
|
|
ssc->size += entry->end - entry->start;
|
|
}
|
|
|
|
/*
|
|
* For each segment in the given memory map, call the given function
|
|
* with a pointer to the map entry and some arbitrary caller-supplied
|
|
* data.
|
|
*/
|
|
static void
|
|
each_writable_segment(vm_map_entry_t map, segment_callback func, void *closure)
|
|
{
|
|
vm_map_entry_t entry;
|
|
|
|
for (entry = map; entry != NULL; entry = entry->next)
|
|
(*func)(entry, closure);
|
|
}
|
|
|
|
static void
|
|
elf_getstatus(pid_t pid, prpsinfo_t *psinfo)
|
|
{
|
|
struct kinfo_proc kobj;
|
|
int name[4];
|
|
size_t len;
|
|
|
|
name[0] = CTL_KERN;
|
|
name[1] = KERN_PROC;
|
|
name[2] = KERN_PROC_PID;
|
|
name[3] = pid;
|
|
|
|
len = sizeof(kobj);
|
|
if (sysctl(name, 4, &kobj, &len, NULL, 0) == -1)
|
|
err(1, "error accessing kern.proc.pid.%u sysctl", pid);
|
|
if (kobj.ki_pid != pid)
|
|
err(1, "error accessing kern.proc.pid.%u sysctl datas", pid);
|
|
strncpy(psinfo->pr_fname, kobj.ki_comm, MAXCOMLEN);
|
|
strncpy(psinfo->pr_psargs, psinfo->pr_fname, PRARGSZ);
|
|
}
|
|
|
|
/*
|
|
* Generate the ELF coredump header into the buffer at "dst". "dst" may
|
|
* be NULL, in which case the header is sized but not actually generated.
|
|
*/
|
|
static void
|
|
elf_puthdr(pid_t pid, vm_map_entry_t map, void *dst, size_t *off, int numsegs)
|
|
{
|
|
struct ptrace_lwpinfo lwpinfo;
|
|
struct {
|
|
prstatus_t status;
|
|
prfpregset_t fpregset;
|
|
prpsinfo_t psinfo;
|
|
thrmisc_t thrmisc;
|
|
} *tempdata;
|
|
size_t ehoff;
|
|
size_t phoff;
|
|
size_t noteoff;
|
|
size_t notesz;
|
|
size_t threads;
|
|
lwpid_t *tids;
|
|
int i;
|
|
|
|
prstatus_t *status;
|
|
prfpregset_t *fpregset;
|
|
prpsinfo_t *psinfo;
|
|
thrmisc_t *thrmisc;
|
|
|
|
ehoff = *off;
|
|
*off += sizeof(Elf_Ehdr);
|
|
|
|
phoff = *off;
|
|
*off += (numsegs + 1) * sizeof(Elf_Phdr);
|
|
|
|
noteoff = *off;
|
|
|
|
if (dst != NULL) {
|
|
if ((tempdata = calloc(1, sizeof(*tempdata))) == NULL)
|
|
errx(1, "out of memory");
|
|
status = &tempdata->status;
|
|
fpregset = &tempdata->fpregset;
|
|
psinfo = &tempdata->psinfo;
|
|
thrmisc = &tempdata->thrmisc;
|
|
} else {
|
|
tempdata = NULL;
|
|
status = NULL;
|
|
fpregset = NULL;
|
|
psinfo = NULL;
|
|
thrmisc = NULL;
|
|
}
|
|
|
|
errno = 0;
|
|
threads = ptrace(PT_GETNUMLWPS, pid, NULL, 0);
|
|
if (errno)
|
|
err(1, "PT_GETNUMLWPS");
|
|
|
|
if (dst != NULL) {
|
|
psinfo->pr_version = PRPSINFO_VERSION;
|
|
psinfo->pr_psinfosz = sizeof(prpsinfo_t);
|
|
elf_getstatus(pid, psinfo);
|
|
|
|
}
|
|
elf_putnote(dst, off, "FreeBSD", NT_PRPSINFO, psinfo,
|
|
sizeof *psinfo);
|
|
|
|
if (dst != NULL) {
|
|
tids = malloc(threads * sizeof(*tids));
|
|
if (tids == NULL)
|
|
errx(1, "out of memory");
|
|
errno = 0;
|
|
ptrace(PT_GETLWPLIST, pid, (void *)tids, threads);
|
|
if (errno)
|
|
err(1, "PT_GETLWPLIST");
|
|
}
|
|
for (i = 0; i < threads; ++i) {
|
|
if (dst != NULL) {
|
|
status->pr_version = PRSTATUS_VERSION;
|
|
status->pr_statussz = sizeof(prstatus_t);
|
|
status->pr_gregsetsz = sizeof(gregset_t);
|
|
status->pr_fpregsetsz = sizeof(fpregset_t);
|
|
status->pr_osreldate = __FreeBSD_version;
|
|
status->pr_pid = tids[i];
|
|
|
|
ptrace(PT_GETREGS, tids[i], (void *)&status->pr_reg, 0);
|
|
ptrace(PT_GETFPREGS, tids[i], (void *)fpregset, 0);
|
|
ptrace(PT_LWPINFO, tids[i], (void *)&lwpinfo,
|
|
sizeof(lwpinfo));
|
|
memset(&thrmisc->_pad, 0, sizeof(thrmisc->_pad));
|
|
strcpy(thrmisc->pr_tname, lwpinfo.pl_tdname);
|
|
}
|
|
elf_putnote(dst, off, "FreeBSD", NT_PRSTATUS, status,
|
|
sizeof *status);
|
|
elf_putnote(dst, off, "FreeBSD", NT_FPREGSET, fpregset,
|
|
sizeof *fpregset);
|
|
elf_putnote(dst, off, "FreeBSD", NT_THRMISC, thrmisc,
|
|
sizeof *thrmisc);
|
|
}
|
|
|
|
notesz = *off - noteoff;
|
|
|
|
if (dst != NULL) {
|
|
free(tids);
|
|
free(tempdata);
|
|
}
|
|
|
|
/* Align up to a page boundary for the program segments. */
|
|
*off = round_page(*off);
|
|
|
|
if (dst != NULL) {
|
|
Elf_Ehdr *ehdr;
|
|
Elf_Phdr *phdr;
|
|
struct phdr_closure phc;
|
|
|
|
/*
|
|
* Fill in the ELF header.
|
|
*/
|
|
ehdr = (Elf_Ehdr *)((char *)dst + ehoff);
|
|
ehdr->e_ident[EI_MAG0] = ELFMAG0;
|
|
ehdr->e_ident[EI_MAG1] = ELFMAG1;
|
|
ehdr->e_ident[EI_MAG2] = ELFMAG2;
|
|
ehdr->e_ident[EI_MAG3] = ELFMAG3;
|
|
ehdr->e_ident[EI_CLASS] = ELF_CLASS;
|
|
ehdr->e_ident[EI_DATA] = ELF_DATA;
|
|
ehdr->e_ident[EI_VERSION] = EV_CURRENT;
|
|
ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
|
|
ehdr->e_ident[EI_ABIVERSION] = 0;
|
|
ehdr->e_ident[EI_PAD] = 0;
|
|
ehdr->e_type = ET_CORE;
|
|
ehdr->e_machine = ELF_ARCH;
|
|
ehdr->e_version = EV_CURRENT;
|
|
ehdr->e_entry = 0;
|
|
ehdr->e_phoff = phoff;
|
|
ehdr->e_flags = 0;
|
|
ehdr->e_ehsize = sizeof(Elf_Ehdr);
|
|
ehdr->e_phentsize = sizeof(Elf_Phdr);
|
|
ehdr->e_phnum = numsegs + 1;
|
|
ehdr->e_shentsize = sizeof(Elf_Shdr);
|
|
ehdr->e_shnum = 0;
|
|
ehdr->e_shstrndx = SHN_UNDEF;
|
|
|
|
/*
|
|
* Fill in the program header entries.
|
|
*/
|
|
phdr = (Elf_Phdr *)((char *)dst + phoff);
|
|
|
|
/* The note segment. */
|
|
phdr->p_type = PT_NOTE;
|
|
phdr->p_offset = noteoff;
|
|
phdr->p_vaddr = 0;
|
|
phdr->p_paddr = 0;
|
|
phdr->p_filesz = notesz;
|
|
phdr->p_memsz = 0;
|
|
phdr->p_flags = 0;
|
|
phdr->p_align = 0;
|
|
phdr++;
|
|
|
|
/* All the writable segments from the program. */
|
|
phc.phdr = phdr;
|
|
phc.offset = *off;
|
|
each_writable_segment(map, cb_put_phdr, &phc);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Emit one note section to "dst", or just size it if "dst" is NULL.
|
|
*/
|
|
static void
|
|
elf_putnote(void *dst, size_t *off, const char *name, int type,
|
|
const void *desc, size_t descsz)
|
|
{
|
|
Elf_Note note;
|
|
|
|
note.n_namesz = strlen(name) + 1;
|
|
note.n_descsz = descsz;
|
|
note.n_type = type;
|
|
if (dst != NULL)
|
|
bcopy(¬e, (char *)dst + *off, sizeof note);
|
|
*off += sizeof note;
|
|
if (dst != NULL)
|
|
bcopy(name, (char *)dst + *off, note.n_namesz);
|
|
*off += roundup2(note.n_namesz, sizeof(Elf_Size));
|
|
if (dst != NULL)
|
|
bcopy(desc, (char *)dst + *off, note.n_descsz);
|
|
*off += roundup2(note.n_descsz, sizeof(Elf_Size));
|
|
}
|
|
|
|
/*
|
|
* Free the memory map.
|
|
*/
|
|
static void
|
|
freemap(vm_map_entry_t map)
|
|
{
|
|
|
|
while (map != NULL) {
|
|
vm_map_entry_t next = map->next;
|
|
free(map);
|
|
map = next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Read the process's memory map using kinfo_getvmmap(), and return a list of
|
|
* VM map entries. Only the non-device read/writable segments are
|
|
* returned. The map entries in the list aren't fully filled in; only
|
|
* the items we need are present.
|
|
*/
|
|
static vm_map_entry_t
|
|
readmap(pid_t pid)
|
|
{
|
|
vm_map_entry_t ent, *linkp, map;
|
|
struct kinfo_vmentry *vmentl, *kve;
|
|
int i, nitems;
|
|
|
|
vmentl = kinfo_getvmmap(pid, &nitems);
|
|
if (vmentl == NULL)
|
|
err(1, "cannot retrieve mappings for %u process", pid);
|
|
|
|
map = NULL;
|
|
linkp = ↦
|
|
for (i = 0; i < nitems; i++) {
|
|
kve = &vmentl[i];
|
|
|
|
/*
|
|
* Ignore 'malformed' segments or ones representing memory
|
|
* mapping with MAP_NOCORE on.
|
|
* If the 'full' support is disabled, just dump the most
|
|
* meaningful data segments.
|
|
*/
|
|
if ((kve->kve_protection & KVME_PROT_READ) == 0 ||
|
|
(kve->kve_flags & KVME_FLAG_NOCOREDUMP) != 0 ||
|
|
kve->kve_type == KVME_TYPE_DEAD ||
|
|
kve->kve_type == KVME_TYPE_UNKNOWN ||
|
|
((pflags & PFLAGS_FULL) == 0 &&
|
|
kve->kve_type != KVME_TYPE_DEFAULT &&
|
|
kve->kve_type != KVME_TYPE_VNODE &&
|
|
kve->kve_type != KVME_TYPE_SWAP))
|
|
continue;
|
|
|
|
ent = calloc(1, sizeof(*ent));
|
|
if (ent == NULL)
|
|
errx(1, "out of memory");
|
|
ent->start = (vm_offset_t)kve->kve_start;
|
|
ent->end = (vm_offset_t)kve->kve_end;
|
|
ent->protection = VM_PROT_READ | VM_PROT_WRITE;
|
|
if ((kve->kve_protection & KVME_PROT_EXEC) != 0)
|
|
ent->protection |= VM_PROT_EXECUTE;
|
|
|
|
*linkp = ent;
|
|
linkp = &ent->next;
|
|
}
|
|
free(vmentl);
|
|
return (map);
|
|
}
|
|
|
|
struct dumpers elfdump = { elf_ident, elf_coredump };
|
|
TEXT_SET(dumpset, elfdump);
|