From 251ac1dcd456c524eb7b79507c4a8a1bf4a4fa32 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Fri, 7 Nov 2014 17:17:54 +0100
Subject: [PATCH 07/41] dump: add API to write elf notes to buffer

Message-id: <1415380693-16593-8-git-send-email-lersek@redhat.com>
Patchwork-id: 62193
O-Subject: [RHEL-7.1 qemu-kvm PATCH 07/26] dump: add API to write elf notes to buffer
Bugzilla: 1157798
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
RH-Acked-by: dgibson <dgibson@redhat.com>

From: qiaonuohan <qiaonuohan@cn.fujitsu.com>

the function can be used by write_elf32_notes/write_elf64_notes to write notes
to a buffer. If fd_write_vmcore is used, write_elf32_notes/write_elf64_notes
will write elf notes to vmcore directly. Instead, if buf_write_note is used,
elf notes will be written to opaque->note_buf at first.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
(cherry picked from commit 4835ef7784502c231f243c3133054850d23dd837)
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 dump.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/dump.c b/dump.c
index 710893f..3c6d526 100644
--- a/dump.c
+++ b/dump.c
@@ -76,6 +76,9 @@ typedef struct DumpState {
     int64_t begin;
     int64_t length;
     Error **errp;
+
+    uint8_t *note_buf;          /* buffer for notes */
+    size_t note_buf_offset;     /* the writing place in note_buf */
 } DumpState;
 
 static int dump_cleanup(DumpState *s)
@@ -755,6 +758,22 @@ static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
     return 0;
 }
 
+static int buf_write_note(const void *buf, size_t size, void *opaque)
+{
+    DumpState *s = opaque;
+
+    /* note_buf is not enough */
+    if (s->note_buf_offset + size > s->note_size) {
+        return -1;
+    }
+
+    memcpy(s->note_buf + s->note_buf_offset, buf, size);
+
+    s->note_buf_offset += size;
+
+    return 0;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
-- 
1.8.3.1