jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
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>
authored by
Paolo Bonzini
and committed by
Stefan Hajnoczi
80ab31b2
1138f246
+27
-29
+27
-29
scripts/qemugdb/coroutine.py
+27
-29
scripts/qemugdb/coroutine.py
···
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'''Undo effect of glibc's PTR_MANGLE()'''
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return gdb.parse_and_eval('(((uint64_t)%s >> 0x11) | ((uint64_t)%s << (64 - 0x11))) ^ (uint64_t)%s' % (val, val, pointer_guard))
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def bt_jmpbuf(jmpbuf):
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'''Backtrace a jmpbuf'''
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def get_jmpbuf_regs(jmpbuf):
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JB_RBX = 0
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JB_RBP = 1
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JB_R12 = 2
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JB_RSP = 6
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JB_PC = 7
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old_rbx = gdb.parse_and_eval('(uint64_t)$rbx')
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old_rbp = gdb.parse_and_eval('(uint64_t)$rbp')
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old_rsp = gdb.parse_and_eval('(uint64_t)$rsp')
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old_r12 = gdb.parse_and_eval('(uint64_t)$r12')
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old_r13 = gdb.parse_and_eval('(uint64_t)$r13')
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old_r14 = gdb.parse_and_eval('(uint64_t)$r14')
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old_r15 = gdb.parse_and_eval('(uint64_t)$r15')
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old_rip = gdb.parse_and_eval('(uint64_t)$rip')
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pointer_guard = get_glibc_pointer_guard()
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gdb.execute('set $rbx = %s' % jmpbuf[JB_RBX])
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gdb.execute('set $rbp = %s' % glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard))
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gdb.execute('set $rsp = %s' % glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard))
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gdb.execute('set $r12 = %s' % jmpbuf[JB_R12])
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gdb.execute('set $r13 = %s' % jmpbuf[JB_R13])
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gdb.execute('set $r14 = %s' % jmpbuf[JB_R14])
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gdb.execute('set $r15 = %s' % jmpbuf[JB_R15])
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gdb.execute('set $rip = %s' % glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard))
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return {'rbx': jmpbuf[JB_RBX],
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'rbp': glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard),
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'rsp': glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard),
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'r12': jmpbuf[JB_R12],
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'r13': jmpbuf[JB_R13],
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'r14': jmpbuf[JB_R14],
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'r15': jmpbuf[JB_R15],
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'rip': glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard) }
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def bt_jmpbuf(jmpbuf):
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'''Backtrace a jmpbuf'''
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regs = get_jmpbuf_regs(jmpbuf)
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old = dict()
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for i in regs:
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old[i] = gdb.parse_and_eval('(uint64_t)$%s' % i)
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for i in regs:
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gdb.execute('set $%s = %s' % (i, regs[i]))
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gdb.execute('bt')
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gdb.execute('set $rbx = %s' % old_rbx)
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gdb.execute('set $rbp = %s' % old_rbp)
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gdb.execute('set $rsp = %s' % old_rsp)
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gdb.execute('set $r12 = %s' % old_r12)
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gdb.execute('set $r13 = %s' % old_r13)
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gdb.execute('set $r14 = %s' % old_r14)
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gdb.execute('set $r15 = %s' % old_r15)
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gdb.execute('set $rip = %s' % old_rip)
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for i in regs:
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gdb.execute('set $%s = %s' % (i, old[i]))
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def coroutine_to_jmpbuf(co):
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coroutine_pointer = co.cast(gdb.lookup_type('CoroutineUContext').pointer())
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return coroutine_pointer['env']['__jmpbuf']
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class CoroutineCommand(gdb.Command):
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gdb.write('usage: qemu coroutine <coroutine-pointer>\n')
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return
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coroutine_pointer = gdb.parse_and_eval(argv[0]).cast(gdb.lookup_type('CoroutineUContext').pointer())
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bt_jmpbuf(coroutine_pointer['env']['__jmpbuf'])
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bt_jmpbuf(coroutine_to_jmpbuf(gdb.parse_and_eval(argv[0])))