Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block patches

# gpg: Signature made Tue Apr 28 15:35:05 2015 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (76 commits)
  block: move I/O request processing to block/io.c
  block: extract bdrv_setup_io_funcs()
  block: add bdrv_set_dirty()/bdrv_reset_dirty() to block_int.h
  block: replace bdrv_states iteration with bdrv_next()
  vmdk: Widen before shifting 32 bit header field
  block/dmg: make it modular
  block/mirror: Always call block_job_sleep_ns()
  iotests: add incremental backup granularity tests
  iotests: add incremental backup failure recovery test
  iotests: add simple incremental backup case
  iotests: add QMP event waiting queue
  iotests: add invalid input incremental backup tests
  hbitmap: truncate tests
  block: Resize bitmaps on bdrv_truncate
  block: Ensure consistent bitmap function prototypes
  block: add BdrvDirtyBitmap documentation
  qmp: Add dirty bitmap status field in query-block
  qmp: add block-dirty-bitmap-clear
  qmp: Add support of "dirty-bitmap" sync mode for drive-backup
  block: Add bitmap successors
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 75 insertions, 0 deletions

diff --git a/scripts/qemu-gdb.py b/scripts/qemu-gdb.py
index 8a0f30534f..6c7f4fbe53 100644
--- a/scripts/qemu-gdb.py
+++ b/scripts/qemu-gdb.py
@@ -22,12 +22,86 @@ def isnull(ptr):
 def int128(p):
     return long(p['lo']) + (long(p['hi']) << 64)
 
+def get_fs_base():
+    '''Fetch %fs base value using arch_prctl(ARCH_GET_FS)'''
+    # %rsp - 120 is scratch space according to the SystemV ABI
+    old = gdb.parse_and_eval('*(uint64_t*)($rsp - 120)')
+    gdb.execute('call arch_prctl(0x1003, $rsp - 120)', False, True)
+    fs_base = gdb.parse_and_eval('*(uint64_t*)($rsp - 120)')
+    gdb.execute('set *(uint64_t*)($rsp - 120) = %s' % old, False, True)
+    return fs_base
+
+def get_glibc_pointer_guard():
+    '''Fetch glibc pointer guard value'''
+    fs_base = get_fs_base()
+    return gdb.parse_and_eval('*(uint64_t*)((uint64_t)%s + 0x30)' % fs_base)
+
+def glibc_ptr_demangle(val, pointer_guard):
+    '''Undo effect of glibc's PTR_MANGLE()'''
+    return gdb.parse_and_eval('(((uint64_t)%s >> 0x11) | ((uint64_t)%s << (64 - 0x11))) ^ (uint64_t)%s' % (val, val, pointer_guard))
+
+def bt_jmpbuf(jmpbuf):
+    '''Backtrace a jmpbuf'''
+    JB_RBX  = 0
+    JB_RBP  = 1
+    JB_R12  = 2
+    JB_R13  = 3
+    JB_R14  = 4
+    JB_R15  = 5
+    JB_RSP  = 6
+    JB_PC   = 7
+
+    old_rbx = gdb.parse_and_eval('(uint64_t)$rbx')
+    old_rbp = gdb.parse_and_eval('(uint64_t)$rbp')
+    old_rsp = gdb.parse_and_eval('(uint64_t)$rsp')
+    old_r12 = gdb.parse_and_eval('(uint64_t)$r12')
+    old_r13 = gdb.parse_and_eval('(uint64_t)$r13')
+    old_r14 = gdb.parse_and_eval('(uint64_t)$r14')
+    old_r15 = gdb.parse_and_eval('(uint64_t)$r15')
+    old_rip = gdb.parse_and_eval('(uint64_t)$rip')
+
+    pointer_guard = get_glibc_pointer_guard()
+    gdb.execute('set $rbx = %s' % jmpbuf[JB_RBX])
+    gdb.execute('set $rbp = %s' % glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard))
+    gdb.execute('set $rsp = %s' % glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard))
+    gdb.execute('set $r12 = %s' % jmpbuf[JB_R12])
+    gdb.execute('set $r13 = %s' % jmpbuf[JB_R13])
+    gdb.execute('set $r14 = %s' % jmpbuf[JB_R14])
+    gdb.execute('set $r15 = %s' % jmpbuf[JB_R15])
+    gdb.execute('set $rip = %s' % glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard))
+
+    gdb.execute('bt')
+
+    gdb.execute('set $rbx = %s' % old_rbx)
+    gdb.execute('set $rbp = %s' % old_rbp)
+    gdb.execute('set $rsp = %s' % old_rsp)
+    gdb.execute('set $r12 = %s' % old_r12)
+    gdb.execute('set $r13 = %s' % old_r13)
+    gdb.execute('set $r14 = %s' % old_r14)
+    gdb.execute('set $r15 = %s' % old_r15)
+    gdb.execute('set $rip = %s' % old_rip)
+
 class QemuCommand(gdb.Command):
     '''Prefix for QEMU debug support commands'''
     def __init__(self):
         gdb.Command.__init__(self, 'qemu', gdb.COMMAND_DATA,
                              gdb.COMPLETE_NONE, True)
 
+class CoroutineCommand(gdb.Command):
+    '''Display coroutine backtrace'''
+    def __init__(self):
+        gdb.Command.__init__(self, 'qemu coroutine', gdb.COMMAND_DATA,
+                             gdb.COMPLETE_NONE)
+
+    def invoke(self, arg, from_tty):
+        argv = gdb.string_to_argv(arg)
+        if len(argv) != 1:
+            gdb.write('usage: qemu coroutine <coroutine-pointer>\n')
+            return
+
+        coroutine_pointer = gdb.parse_and_eval(argv[0]).cast(gdb.lookup_type('CoroutineUContext').pointer())
+        bt_jmpbuf(coroutine_pointer['env']['__jmpbuf'])
+
 class MtreeCommand(gdb.Command):
     '''Display the memory tree hierarchy'''
     def __init__(self):
@@ -86,4 +160,5 @@ class MtreeCommand(gdb.Command):
             subregion = subregion['subregions_link']['tqe_next']
 
 QemuCommand()
+CoroutineCommand()
 MtreeCommand()