Add the CTF source file which gets shared with link_elf.c and link_elf_obj.c.

1 files changed, 325 insertions, 0 deletions

diff --git a/sys/kern/kern_ctf.c b/sys/kern/kern_ctf.c
new file mode 100644
index 0000000..758ad81
--- /dev/null
+++ b/sys/kern/kern_ctf.c
@@ -0,0 +1,325 @@
+/*-
+ * Copyright (c) 2008 John Birrell <jb@freebsd.org>
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Note this file is included by both link_elf.c and link_elf_obj.c.
+ *
+ * The CTF header structure definition can't be used here because it's
+ * (annoyingly) covered by the CDDL. We will just use a few bytes from
+ * it as an integer array where we 'know' what they mean.
+ */
+#define CTF_HDR_SIZE		36
+#define CTF_HDR_STRTAB_U32	7
+#define CTF_HDR_STRLEN_U32	8
+
+#ifdef DDB_CTF
+static void *
+z_alloc(void *nil, u_int items, u_int size)
+{
+	void *ptr;
+
+	ptr = malloc(items * size, M_TEMP, M_NOWAIT);
+	return ptr;
+}
+
+static void
+z_free(void *nil, void *ptr)
+{
+	free(ptr, M_TEMP);
+}
+
+#endif
+
+static int
+link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc)
+{
+#ifdef DDB_CTF
+	Elf_Ehdr *hdr = NULL;
+	Elf_Shdr *shdr = NULL;
+	caddr_t ctftab = NULL;
+	caddr_t raw = NULL;
+	caddr_t shstrtab = NULL;
+	elf_file_t ef = (elf_file_t) lf;
+	int flags;
+	int i;
+	int nbytes;
+	int resid;
+	int vfslocked;
+	size_t sz;
+	struct nameidata nd;
+	struct thread *td = curthread;
+	uint8_t ctf_hdr[CTF_HDR_SIZE];
+#endif
+	int error = 0;
+
+	if (lf == NULL || lc == NULL)
+		return (EINVAL);
+
+	/* Set the defaults for no CTF present. That's not a crime! */
+	bzero(lc, sizeof(*lc));
+
+#ifdef DDB_CTF
+	/*
+	 * First check if we've tried to load CTF data previously and the
+	 * CTF ELF section wasn't found. We flag that condition by setting
+	 * ctfcnt to -1. See below.
+	 */
+	if (ef->ctfcnt < 0)
+		return (0);
+
+	/* Now check if we've already loaded the CTF data.. */
+	if (ef->ctfcnt > 0) {
+		/* We only need to load once. */
+		lc->ctftab = ef->ctftab;
+		lc->ctfcnt = ef->ctfcnt;
+		lc->symtab = ef->ddbsymtab;
+		lc->strtab = ef->ddbstrtab;
+		lc->strcnt = ef->ddbstrcnt;
+		lc->nsym   = ef->ddbsymcnt;
+		lc->ctfoffp = (uint32_t **) &ef->ctfoff;
+		lc->typoffp = (uint32_t **) &ef->typoff;
+		lc->typlenp = &ef->typlen;
+		return (0);
+	}
+
+	/*
+	 * We need to try reading the CTF data. Flag no CTF data present
+	 * by default and if we actually succeed in reading it, we'll
+	 * update ctfcnt to the number of bytes read.
+	 */
+	ef->ctfcnt = -1;
+
+	NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, lf->pathname, td);
+	flags = FREAD;
+	error = vn_open(&nd, &flags, 0, NULL);
+	if (error)
+		return (error);
+	vfslocked = NDHASGIANT(&nd);
+	NDFREE(&nd, NDF_ONLY_PNBUF);
+
+	/* Allocate memory for the FLF header. */
+	if ((hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK)) == NULL) {
+		error = ENOMEM;
+		goto out;
+	}
+
+	/* Read the ELF header. */
+	if ((error = vn_rdwr(UIO_READ, nd.ni_vp, hdr, sizeof(*hdr),
+	    0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid,
+	    td)) != 0)
+		goto out;
+
+	/* Sanity check. */
+	if (!IS_ELF(*hdr)) {
+		error = ENOEXEC;
+		goto out;
+	}
+
+	nbytes = hdr->e_shnum * hdr->e_shentsize;
+	if (nbytes == 0 || hdr->e_shoff == 0 ||
+	    hdr->e_shentsize != sizeof(Elf_Shdr)) {
+		error = ENOEXEC;
+		goto out;
+	}
+
+	/* Allocate memory for all the section headers */
+	if ((shdr = malloc(nbytes, M_LINKER, M_WAITOK)) == NULL) {
+		error = ENOMEM;
+		goto out;
+	}
+
+	/* Read all the section headers */
+	if ((error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes,
+	    hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
+	    &resid, td)) != 0)
+		goto out;
+
+	/*
+	 * We need to search for the CTF section by name, so if the
+	 * section names aren't present, then we can't locate the
+	 * .SUNW_ctf section containing the CTF data.
+	 */
+	if (hdr->e_shstrndx == 0 || shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB)
+		goto out;
+
+	/* Allocate memory to buffer the section header strings. */
+	if ((shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER,
+	    M_WAITOK)) == NULL) {
+		error = ENOMEM;
+		goto out;
+	}
+
+	/* Read the section header strings. */
+	if ((error = vn_rdwr(UIO_READ, nd.ni_vp, shstrtab,
+	    shdr[hdr->e_shstrndx].sh_size, shdr[hdr->e_shstrndx].sh_offset,
+	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid,
+	    td)) != 0)
+		goto out;
+
+	/* Search for the section containing the CTF data. */
+	for (i = 0; i < hdr->e_shnum; i++)
+		if (strcmp(".SUNW_ctf", shstrtab + shdr[i].sh_name) == 0)
+			break;
+
+	/* Check if the CTF section wasn't found. */
+	if (i >= hdr->e_shnum)
+		goto out;
+
+	/* Read the CTF header. */
+	if ((error = vn_rdwr(UIO_READ, nd.ni_vp, ctf_hdr, sizeof(ctf_hdr),
+	    shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
+	    NOCRED, &resid, td)) != 0)
+		goto out;
+
+	/* Check the CTF magic number. (XXX check for big endian!) */
+	if (ctf_hdr[0] != 0xf1 || ctf_hdr[1] != 0xcf)
+		goto out;
+
+	/* Check if version 2. */
+	if (ctf_hdr[2] != 2)
+		goto out;
+
+	/* Check if the data is compressed. */
+	if ((ctf_hdr[3] & 0x1) != 0) {
+		uint32_t *u32 = (uint32_t *) ctf_hdr;
+
+		/*
+		 * The last two fields in the CTF header are the offset
+		 * from the end of the header to the start of the string
+		 * data and the length of that string data. se this
+		 * information to determine the decompressed CTF data
+		 * buffer required.
+		 */
+		sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] +
+		    sizeof(ctf_hdr);
+
+		/*
+		 * Allocate memory for the compressed CTF data, including
+		 * the header (which isn't compressed).
+		 */
+		if ((raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK)) == NULL) {
+			error = ENOMEM;
+			goto out;
+		}
+	} else {
+		/*
+		 * The CTF data is not compressed, so the ELF section
+		 * size is the same as the buffer size required.
+		 */
+		sz = shdr[i].sh_size;
+	}
+
+	/*
+	 * Allocate memory to buffer the CTF data in it's decompressed
+	 * form.
+	 */
+	if ((ctftab = malloc(sz, M_LINKER, M_WAITOK)) == NULL) {
+		error = ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * Read the CTF data into the raw buffer if compressed, or
+	 * directly into the CTF buffer otherwise.
+	 */
+	if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw,
+	    shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
+	    td->td_ucred, NOCRED, &resid, td)) != 0)
+		goto out;
+
+	/* Check if decompression is required. */
+	if (raw != NULL) {
+		z_stream zs;
+		int ret;
+
+		/*
+		 * The header isn't compressed, so copy that into the
+		 * CTF buffer first.
+		 */
+		bcopy(ctf_hdr, ctftab, sizeof(ctf_hdr));
+
+		/* Initialise the zlib structure. */
+		bzero(&zs, sizeof(zs));
+		zs.zalloc = z_alloc;
+		zs.zfree = z_free;
+
+		if (inflateInit(&zs) != Z_OK) {
+			error = EIO;
+			goto out;
+		}
+
+		zs.avail_in = shdr[i].sh_size - sizeof(ctf_hdr);
+		zs.next_in = ((uint8_t *) raw) + sizeof(ctf_hdr);
+		zs.avail_out = sz - sizeof(ctf_hdr);
+		zs.next_out = ((uint8_t *) ctftab) + sizeof(ctf_hdr);
+		if ((ret = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
+			printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret);
+			error = EIO;
+			goto out;
+		}
+	}
+
+	/* Got the CTF data! */
+	ef->ctftab = ctftab;
+	ef->ctfcnt = shdr[i].sh_size;
+
+	/* We'll retain the memory allocated for the CTF data. */
+	ctftab = NULL;
+
+	/* Let the caller use the CTF data read. */
+	lc->ctftab = ef->ctftab;
+	lc->ctfcnt = ef->ctfcnt;
+	lc->symtab = ef->ddbsymtab;
+	lc->strtab = ef->ddbstrtab;
+	lc->strcnt = ef->ddbstrcnt;
+	lc->nsym   = ef->ddbsymcnt;
+	lc->ctfoffp = (uint32_t **) &ef->ctfoff;
+	lc->typoffp = (uint32_t **) &ef->typoff;
+	lc->typlenp = &ef->typlen;
+
+out:
+	VOP_UNLOCK(nd.ni_vp, 0);
+	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
+	VFS_UNLOCK_GIANT(vfslocked);
+
+	if (hdr != NULL)
+		free(hdr, M_LINKER);
+	if (shdr != NULL)
+		free(shdr, M_LINKER);
+	if (shstrtab != NULL)
+		free(shstrtab, M_LINKER);
+	if (ctftab != NULL)
+		free(ctftab, M_LINKER);
+	if (raw != NULL)
+		free(raw, M_LINKER);
+#else
+	error = EOPNOTSUPP;
+#endif
+
+	return (error);
+}