[compiler-rt][RISCV] Avoid using __init_riscv_feature_bits as a direc… #115316
Conversation
…t constructor `__init_riscv_feature_bits` takes an argument that can be platform-specific, potentially pointing to the VDSO address of the hwprobe system call for Linux. However, marking it as a constructor does not guarantee that 0/NULL will always be passed to this argument, which may result in treating an uninitialized or garbage value as a pointer to hwprobe, leading to a crash. The simplest solution is to introduce a small constructor function to ensure that the platform-specific argument is set to 0/NULL.
|
✅ With the latest revision this PR passed the C/C++ code formatter. |
There was a problem hiding this comment.
Sounds reasonable to me.
Given your recent update to the wording in C api, can you check that the lengths are being left as zero until e.g. hwprobes are successful? The setting of lengths on (new) line 359/360 looks a little strange to me, given (new) line 369 seems to return if initHwProbe fails.
Yeah I think that should fix as well, but let me create another PR for that :) |
llvm#115316) …t constructor `__init_riscv_feature_bits` takes an argument that can be platform-specific, potentially pointing to the VDSO address of the hwprobe system call for Linux. However, marking it as a constructor does not guarantee that 0/NULL will always be passed to this argument, which may result in treating an uninitialized or garbage value as a pointer to hwprobe, leading to a crash. The simplest solution is to introduce a small constructor function to ensure that the platform-specific argument is set to 0/NULL.
…t constructor
__init_riscv_feature_bitstakes an argument that can be platform-specific, potentially pointing to the VDSO address of the hwprobe system call for Linux. However, marking it as a constructor does not guarantee that 0/NULL will always be passed to this argument, which may result in treating an uninitialized or garbage value as a pointer to hwprobe, leading to a crash.The simplest solution is to introduce a small constructor function to ensure that the platform-specific argument is set to 0/NULL.