From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:35881) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gr5GJ-0002LC-5k for qemu-devel@nongnu.org; Tue, 05 Feb 2019 13:16:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gr5GG-0003lD-Ns for qemu-devel@nongnu.org; Tue, 05 Feb 2019 13:15:59 -0500 Received: from mail-wm1-x342.google.com ([2a00:1450:4864:20::342]:53256) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gr5GG-0003Yc-Dp for qemu-devel@nongnu.org; Tue, 05 Feb 2019 13:15:56 -0500 Received: by mail-wm1-x342.google.com with SMTP id d15so4678074wmb.3 for ; Tue, 05 Feb 2019 10:15:41 -0800 (PST) Sender: Paolo Bonzini From: Paolo Bonzini Date: Tue, 5 Feb 2019 19:14:22 +0100 Message-Id: <1549390526-24246-13-git-send-email-pbonzini@redhat.com> In-Reply-To: <1549390526-24246-1-git-send-email-pbonzini@redhat.com> References: <1549390526-24246-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PULL 12/76] elf-ops.h: Add get_elf_note_type() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org From: Liam Merwick Introduce a routine which, given a pointer to a range of ELF Notes, searches through them looking for a note matching the type specified and returns a pointer to the matching ELF note. get_elf_note_type() is used by elf_load[32|64]() to find the specified note type required by the 'elf_note_fn' parameter added in the previous commit. Signed-off-by: Liam Merwick Signed-off-by: Paolo Bonzini Signed-off-by: Liam Merwick --- include/hw/elf_ops.h | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h index 3438d6f..690f923 100644 --- a/include/hw/elf_ops.h +++ b/include/hw/elf_ops.h @@ -265,6 +265,51 @@ fail: return ret; } +/* + * Given 'nhdr', a pointer to a range of ELF Notes, search through them + * for a note matching type 'elf_note_type' and return a pointer to + * the matching ELF note. + */ +static struct elf_note *glue(get_elf_note_type, SZ)(struct elf_note *nhdr, + elf_word note_size, + elf_word phdr_align, + elf_word elf_note_type) +{ + elf_word nhdr_size = sizeof(struct elf_note); + elf_word elf_note_entry_offset = 0; + elf_word note_type; + elf_word nhdr_namesz; + elf_word nhdr_descsz; + + if (nhdr == NULL) { + return NULL; + } + + note_type = nhdr->n_type; + while (note_type != elf_note_type) { + nhdr_namesz = nhdr->n_namesz; + nhdr_descsz = nhdr->n_descsz; + + elf_note_entry_offset = nhdr_size + + QEMU_ALIGN_UP(nhdr_namesz, phdr_align) + + QEMU_ALIGN_UP(nhdr_descsz, phdr_align); + + /* + * If the offset calculated in this iteration exceeds the + * supplied size, we are done and no matching note was found. + */ + if (elf_note_entry_offset > note_size) { + return NULL; + } + + /* skip to the next ELF Note entry */ + nhdr = (void *)nhdr + elf_note_entry_offset; + note_type = nhdr->n_type; + } + + return nhdr; +} + static int glue(load_elf, SZ)(const char *name, int fd, uint64_t (*elf_note_fn)(void *, void *, bool), uint64_t (*translate_fn)(void *, uint64_t), @@ -497,6 +542,36 @@ static int glue(load_elf, SZ)(const char *name, int fd, high = addr + mem_size; data = NULL; + + } else if (ph->p_type == PT_NOTE && elf_note_fn) { + struct elf_note *nhdr = NULL; + + file_size = ph->p_filesz; /* Size of the range of ELF notes */ + data = g_malloc0(file_size); + if (ph->p_filesz > 0) { + if (lseek(fd, ph->p_offset, SEEK_SET) < 0) { + goto fail; + } + if (read(fd, data, file_size) != file_size) { + goto fail; + } + } + + /* + * Search the ELF notes to find one with a type matching the + * value passed in via 'translate_opaque' + */ + nhdr = (struct elf_note *)data; + assert(translate_opaque != NULL); + nhdr = glue(get_elf_note_type, SZ)(nhdr, file_size, ph->p_align, + *(uint64_t *)translate_opaque); + if (nhdr != NULL) { + bool is64 = + sizeof(struct elf_note) == sizeof(struct elf64_note); + elf_note_fn((void *)nhdr, (void *)&ph->p_align, is64); + } + g_free(data); + data = NULL; } } -- 1.8.3.1