Commit Graph

5 Commits

Author SHA1 Message Date
Alessandro Arzilli
b53fcbe43a
proc: fix RFLAGS corruption after call injection on amd64 (#3002)
debugCallV2 for amd64 has a bug where it corrupts the flags registers
every time it is called, this commit works around that problem by
restoring flags one extra time to its original value after stepping out
of debugCallV2.

Fixes #2985
2022-05-05 08:41:40 -07:00
Alessandro Arzilli
1b0c4310c4
proc: give unique addresses to registerized variables (#2527)
We told clients that further loading of variables can be done by
specifying a type cast using the address of a variable that we
returned.
This does not work for registerized variables (or, in general,
variables that have a complex location expression) because we don't
give them unique addresses and we throw away the compositeMemory object
we made to read them.

This commit changes proc so that:

1. variables with location expression divided in pieces do get a unique
   memory address
2. the compositeMemory object is saved somewhere
3. when an integer is cast back into a pointer type we look through our
   saved compositeMemory objects to see if there is one that covers the
   specified address and use it.

The unique memory addresses we generate have the MSB set to 1, as
specified by the Intel 86x64 manual addresses in this form are reserved
for kernel memory (which we can not read anyway) so we are guaranteed
to never generate a fake memory address that overlaps a real memory
address of the application.

The unfortunate side effect of this is that it will break clients that
do not deserialize the address to a 64bit integer. This practice is
contrary to how we defined our types and contrary to the specification
of the JSON format, as of json.org, however it is also fairly common,
due to javascript itself having only 53bit integers.

We could come up with a new mechanism but then even more old clients
would have to be changed.
2021-07-02 18:37:55 +02:00
Alessandro Arzilli
35d4f05c4e
proc: remove duplicate Registers.Get implementations (#2415)
Moves the implementation of Registers.Get out of the backends and into
proc where it can be implemented only once per architecture.
2021-04-28 10:00:26 -07:00
Alessandro Arzilli
6a70d531bb
proc/*: implement proc.(*compositeMemory).WriteMemory (#2271)
Delve represents registerized variables (fully or partially) using
compositeMemory, implementing proc.(*compositeMemory).WriteMemory is
necessary to make SetVariable and function calls work when Go will
switch to using the register calling convention in 1.17.

This commit also makes some refactoring by moving the code that
converts between register numbers and register names out of pkg/proc
into a different package.
2021-03-04 10:28:28 -08:00
aarzilli
136f4de4b8 proc: keep track of nesting depth while reading compile units
Fully read compile units that contain nested entries we don't
understand (such as DW_TAG_namespace) by keeping track of the depth
we're at.
2020-07-16 15:34:00 +02:00