Casting a char pointer to struct ctf_header causes bus error on

sparc64.  Use memcpy() to align the data.
found by regress/usr.bin/ctfdump; OK mpi@

diff --git a/usr.bin/ctfdump/ctfdump.c b/usr.bin/ctfdump/ctfdump.c
index 0b3f532..945cfc8 100644 (file)
--- a/usr.bin/ctfdump/ctfdump.c
+++ b/usr.bin/ctfdump/ctfdump.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ctfdump.c,v 1.24 2019/09/03 10:32:15 mpi Exp $ */
+/*     $OpenBSD: ctfdump.c,v 1.25 2022/02/10 23:40:09 bluhm Exp $ */
 
 /*
  * Copyright (c) 2016 Martin Pieuchot <mpi@openbsd.org>
@@ -273,39 +273,40 @@ elf_dump(uint8_t flags)
 int
 isctf(const char *p, size_t filesize)
 {
-       struct ctf_header       *cth = (struct ctf_header *)p;
-       off_t                    dlen;
+       struct ctf_header        cth;
+       off_t                    dlen;
 
        if (filesize < sizeof(struct ctf_header)) {
                warnx("file too small to be CTF");
                return 0;
        }
 
-       if (cth->cth_magic != CTF_MAGIC || cth->cth_version != CTF_VERSION)
+       memcpy(&cth, p, sizeof(struct ctf_header));
+       if (cth.cth_magic != CTF_MAGIC || cth.cth_version != CTF_VERSION)
                return 0;
 
-       dlen = (off_t)cth->cth_stroff + cth->cth_strlen;
-       if (dlen > (off_t)filesize && !(cth->cth_flags & CTF_F_COMPRESS)) {
+       dlen = (off_t)cth.cth_stroff + cth.cth_strlen;
+       if (dlen > (off_t)filesize && !(cth.cth_flags & CTF_F_COMPRESS)) {
                warnx("bogus file size");
                return 0;
        }
 
-       if ((cth->cth_lbloff & 3) || (cth->cth_objtoff & 1) ||
-           (cth->cth_funcoff & 1) || (cth->cth_typeoff & 3)) {
+       if ((cth.cth_lbloff & 3) || (cth.cth_objtoff & 1) ||
+           (cth.cth_funcoff & 1) || (cth.cth_typeoff & 3)) {
                warnx("wrongly aligned offset");
                return 0;
        }
 
-       if ((cth->cth_lbloff >= dlen) || (cth->cth_objtoff >= dlen) ||
-           (cth->cth_funcoff >= dlen) || (cth->cth_typeoff >= dlen)) {
+       if ((cth.cth_lbloff >= dlen) || (cth.cth_objtoff >= dlen) ||
+           (cth.cth_funcoff >= dlen) || (cth.cth_typeoff >= dlen)) {
                warnx("truncated file");
                return 0;
        }
 
-       if ((cth->cth_lbloff > cth->cth_objtoff) ||
-           (cth->cth_objtoff > cth->cth_funcoff) ||
-           (cth->cth_funcoff > cth->cth_typeoff) ||
-           (cth->cth_typeoff > cth->cth_stroff)) {
+       if ((cth.cth_lbloff > cth.cth_objtoff) ||
+           (cth.cth_objtoff > cth.cth_funcoff) ||
+           (cth.cth_funcoff > cth.cth_typeoff) ||
+           (cth.cth_typeoff > cth.cth_stroff)) {
                warnx("corrupted file");
                return 0;
        }
@@ -316,45 +317,46 @@ isctf(const char *p, size_t filesize)
 int
 ctf_dump(const char *p, size_t size, uint8_t flags)
 {
-       struct ctf_header       *cth = (struct ctf_header *)p;
-       off_t                    dlen;
+       struct ctf_header        cth;
+       off_t                    dlen;
        char                    *data;
 
-       dlen = (off_t)cth->cth_stroff + cth->cth_strlen;
-       if (cth->cth_flags & CTF_F_COMPRESS) {
-               data = decompress(p + sizeof(*cth), size - sizeof(*cth), dlen);
+       memcpy(&cth, p, sizeof(struct ctf_header));
+       dlen = (off_t)cth.cth_stroff + cth.cth_strlen;
+       if (cth.cth_flags & CTF_F_COMPRESS) {
+               data = decompress(p + sizeof(cth), size - sizeof(cth), dlen);
                if (data == NULL)
                        return 1;
        } else {
-               data = (char *)p + sizeof(*cth);
+               data = (char *)p + sizeof(cth);
        }
 
        if (flags & DUMP_HEADER) {
-               printf("  cth_magic    = 0x%04x\n", cth->cth_magic);
-               printf("  cth_version  = %u\n", cth->cth_version);
-               printf("  cth_flags    = 0x%02x\n", cth->cth_flags);
+               printf("  cth_magic    = 0x%04x\n", cth.cth_magic);
+               printf("  cth_version  = %u\n", cth.cth_version);
+               printf("  cth_flags    = 0x%02x\n", cth.cth_flags);
                printf("  cth_parlabel = %s\n",
-                   ctf_off2name(cth, data, dlen, cth->cth_parlabel));
+                   ctf_off2name(&cth, data, dlen, cth.cth_parlabel));
                printf("  cth_parname  = %s\n",
-                   ctf_off2name(cth, data, dlen, cth->cth_parname));
-               printf("  cth_lbloff   = %u\n", cth->cth_lbloff);
-               printf("  cth_objtoff  = %u\n", cth->cth_objtoff);
-               printf("  cth_funcoff  = %u\n", cth->cth_funcoff);
-               printf("  cth_typeoff  = %u\n", cth->cth_typeoff);
-               printf("  cth_stroff   = %u\n", cth->cth_stroff);
-               printf("  cth_strlen   = %u\n", cth->cth_strlen);
+                   ctf_off2name(&cth, data, dlen, cth.cth_parname));
+               printf("  cth_lbloff   = %u\n", cth.cth_lbloff);
+               printf("  cth_objtoff  = %u\n", cth.cth_objtoff);
+               printf("  cth_funcoff  = %u\n", cth.cth_funcoff);
+               printf("  cth_typeoff  = %u\n", cth.cth_typeoff);
+               printf("  cth_stroff   = %u\n", cth.cth_stroff);
+               printf("  cth_strlen   = %u\n", cth.cth_strlen);
                printf("\n");
        }
 
        if (flags & DUMP_LABEL) {
-               uint32_t                 lbloff = cth->cth_lbloff;
+               uint32_t                 lbloff = cth.cth_lbloff;
                struct ctf_lblent       *ctl;
 
-               while (lbloff < cth->cth_objtoff) {
+               while (lbloff < cth.cth_objtoff) {
                        ctl = (struct ctf_lblent *)(data + lbloff);
 
                        printf("  %5u %s\n", ctl->ctl_typeidx,
-                           ctf_off2name(cth, data, dlen, ctl->ctl_label));
+                           ctf_off2name(&cth, data, dlen, ctl->ctl_label));
 
                        lbloff += sizeof(*ctl);
                }
@@ -362,13 +364,13 @@ ctf_dump(const char *p, size_t size, uint8_t flags)
        }
 
        if (flags & DUMP_OBJECT) {
-               uint32_t                 objtoff = cth->cth_objtoff;
+               uint32_t                 objtoff = cth.cth_objtoff;
                size_t                   idx = 0, i = 0;
                uint16_t                *dsp;
                const char              *s;
                int                      l;
 
-               while (objtoff < cth->cth_funcoff) {
+               while (objtoff < cth.cth_funcoff) {
                        dsp = (uint16_t *)(data + objtoff);
 
                        l = printf("  [%zu] %u", i++, *dsp);
@@ -389,8 +391,8 @@ ctf_dump(const char *p, size_t size, uint8_t flags)
                const char              *s;
                int                      l;
 
-               fstart = (uint16_t *)(data + cth->cth_funcoff);
-               fend = (uint16_t *)(data + cth->cth_typeoff);
+               fstart = (uint16_t *)(data + cth.cth_funcoff);
+               fend = (uint16_t *)(data + cth.cth_typeoff);
 
                fsp = fstart;
                while (fsp < fend) {
@@ -415,11 +417,11 @@ ctf_dump(const char *p, size_t size, uint8_t flags)
        }
 
        if (flags & DUMP_TYPE) {
-               uint32_t                 idx = 1, offset = cth->cth_typeoff;
-               uint32_t                 stroff = cth->cth_stroff;
+               uint32_t                 idx = 1, offset = cth.cth_typeoff;
+               uint32_t                 stroff = cth.cth_stroff;
 
                while (offset < stroff) {
-                       ctf_dump_type(cth, data, dlen, stroff, &offset, idx++);
+                       ctf_dump_type(&cth, data, dlen, stroff, &offset, idx++);
                }
                printf("\n");
        }
@@ -428,8 +430,8 @@ ctf_dump(const char *p, size_t size, uint8_t flags)
                uint32_t                 offset = 0;
                const char              *str;
 
-               while (offset < cth->cth_strlen) {
-                       str = ctf_off2name(cth, data, dlen, offset);
+               while (offset < cth.cth_strlen) {
+                       str = ctf_off2name(&cth, data, dlen, offset);
 
                        printf("  [%u] ", offset);
                        if (strcmp(str, "(anon)"))
@@ -442,7 +444,7 @@ ctf_dump(const char *p, size_t size, uint8_t flags)
                printf("\n");
        }
 
-       if (cth->cth_flags & CTF_F_COMPRESS)
+       if (cth.cth_flags & CTF_F_COMPRESS)
                free(data);
 
        return 0;