qemu-gdb: extract parts of "qemu coroutine" implementation

Provide useful Python functions to reach and decipher a jmpbuf.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
master
Paolo Bonzini 2015-10-12 10:02:53 +02:00 committed by Stefan Hajnoczi
parent 1138f24645
commit 80ab31b257
1 changed files with 27 additions and 29 deletions

View File

@ -47,8 +47,7 @@ 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'''
def get_jmpbuf_regs(jmpbuf):
JB_RBX = 0
JB_RBP = 1
JB_R12 = 2
@ -58,35 +57,35 @@ def bt_jmpbuf(jmpbuf):
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 $rip = %s' % glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard))
return {'rbx': jmpbuf[JB_RBX],
'rbp': glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard),
'rsp': glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard),
'r12': jmpbuf[JB_R12],
'r13': jmpbuf[JB_R13],
'r14': jmpbuf[JB_R14],
'r15': jmpbuf[JB_R15],
'rip': glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard) }
def bt_jmpbuf(jmpbuf):
'''Backtrace a jmpbuf'''
regs = get_jmpbuf_regs(jmpbuf)
old = dict()
for i in regs:
old[i] = gdb.parse_and_eval('(uint64_t)$%s' % i)
for i in regs:
gdb.execute('set $%s = %s' % (i, regs[i]))
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)
for i in regs:
gdb.execute('set $%s = %s' % (i, old[i]))
def coroutine_to_jmpbuf(co):
coroutine_pointer = co.cast(gdb.lookup_type('CoroutineUContext').pointer())
return coroutine_pointer['env']['__jmpbuf']
class CoroutineCommand(gdb.Command):
@ -101,5 +100,4 @@ class CoroutineCommand(gdb.Command):
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'])
bt_jmpbuf(coroutine_to_jmpbuf(gdb.parse_and_eval(argv[0])))