Ensure all ptrace() and /proc/<pid> IO is through an interface #167
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When Android Isolated Process is enabled, every process exists in its own ephemeral UID and SELinux context. That will essentially block `ptrace()` and I/O to `/proc/<pid>`, which means minidump-writer currently can't be used to dump Isolated Processes. This change refactors existing code to do all forbidden operations through a trait, `ProcessInspector`, that currently only has one implementation - `DirectInspector` - which calls the APIs directly (like the current implementation does). In the next change, we will add another implementation of `ProcessInspector` - `remote::InspectorInvoker` and its other half `remote::InspectorExecutor` - That will allow minidump-writer to send `ptrace()` and `/proc/<pid>` I/O requests to a remote process that does have the required permissions.
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gabrielesvelto
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This looks like a refactoring of the existing code but without introducing the new proxy-based ProcessInspector. These changes look fine the way they are but did you forget adding the new implementation to the PR?
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| // TODO - Does this ptrace(PTRACE_GETREGS) and ptrace(PTRACE_GETFPREGS) stuff need to be | ||
| // abstracted too? Breakpad doesn't do it, but it seems like the type of thing that | ||
| // should be stopped by Isolated Processes... |
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Yes, given the isolation is around the uid/gid then these calls should also fail unless they're proxy-ed.
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| pub fn write_dso_debug_stream( | ||
| process_inspector: &mut dyn ProcessInspector, |
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I noticed you're declaring this argument as mutable here and in several other places, but from what I can tell it doesn't need to be mutable. Surprisingly clippy doesn't complain 🤷. Is this because of the proxy-ed reader?
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When Android Isolated Process is enabled, every process exists in its own ephemeral UID and SELinux context. That will essentially block
ptrace()and I/O to/proc/<pid>, which means minidump-writer currently can't be used to dump Isolated Processes.This change refactors existing code to do all forbidden operations through a trait,
ProcessInspector, that currently only has one implementation -DirectInspector- which calls the APIs directly (like the current implementation does).In the next change, we will add another implementation of
ProcessInspector-remote::InspectorInvokerand its other halfremote::InspectorExecutor- That will allow minidump-writer to sendptrace()and/proc/<pid>I/O requests to a remote process that does have the required permissions.Fixes #166