Resolve OEM inline hook veneers to prevent infinite recursion#579
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JingMatrix wants to merge 1 commit intomasterfrom
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Resolve OEM inline hook veneers to prevent infinite recursion#579JingMatrix wants to merge 1 commit intomasterfrom
JingMatrix wants to merge 1 commit intomasterfrom
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On heavily customized Android ROMs, the OEM dynamically hotpatches libart.so methods using a 16-byte ARM64 veneer (`ldr x16/17, pc+8; br x16/17`). When Dobby attempts to hook these pre-applied veneers, its literal relocator handles the `ldr x, pc+offset` instruction incorrectly by reading the overwritten literal pool at runtime, resulting in an infinite recursion loop and a SIGSEGV (stack overflow) in system_server. This commit introduces a workaround for ARM64: we actively check if the target address starts with this known trampoline signature. If found, we extract the absolute address from `pc+8` and apply our hook directly to the OEM's real implementation. This safely chains our hooks onto the OEM's hotpatch framework. Currently experimental and primarily for testing purposes.
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This pull-request is unlikely to be merged, we however provide local logs to illustrate the issues addressed here: |
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On heavily customized Android ROMs, the OEM dynamically hotpatches libart.so methods using a 16-byte ARM64 veneer (
ldr x16/17, pc+8; br x16/17).When Dobby attempts to hook these pre-applied veneers, its literal relocator handles the
ldr x, pc+offsetinstruction incorrectly by reading the overwritten literal pool at runtime, resulting in an infinite recursion loop and a SIGSEGV (stack overflow) in system_server.This commit introduces a workaround for ARM64: we actively check if the target address starts with this known trampoline signature. If found, we extract the absolute address from
pc+8and apply our hook directly to the OEM's real implementation.This safely chains our hooks onto the OEM's hotpatch framework. Currently experimental and primarily for testing purposes.