uclibc-compat: split .so and .a to fix segfault from symbol interposition - #2000
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libuclibc-compat.so was exporting stat/mmap which overrode musl's implementations for ALL code in the process, including musl's own internal calls. This caused segfaults because musl expects 64-bit off_t but the shim's mmap takes uint32_t. Split into two libraries: - libuclibc-compat.so: only symbols MISSING from musl (__ctype_b, __assert, __fgetc_unlocked, memcpy_s, etc). Safe as shared lib. - libuclibc-compat-static.a: stat/mmap wrappers with uclibc-compatible ABI. Must be statically linked into the executable so overrides only affect vendor .so lookups through the executable's symbol scope. BUNDLE_SDK now builds and includes both in the toolchain tarball. Fixes: segfault in majestic on hi3516cv100 at hisi_free_mem_ex (mmap) Ref: #1992 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Vendor glibc binaries from the V2 era (e.g. hi3520dv200's libmpi.so) were built without _FILE_OFFSET_BITS=64 so their mmap() takes a 32-bit off_t. musl's mmap() exports 64-bit off_t — when libmpi dynamic-links against musl on a modern rootfs, the high 32 bits of the offset arg come from uninitialised stack and the kernel sees a garbage pgoff, rejecting with EINVAL. Symptom on hi3520dv200: every HI_MPI_VENC_CreateChn returns 0xa007800c (EN_ERR_VENC_NOMEM) because libmpi can't mmap the model_buf via /dev/venc. Confirmed via LD_PRELOAD trace shim that wraps mmap(): the syscall reaches the kernel with off=0x402b65d8 — a userspace VA (varies between runs with ASLR), clearly stack garbage. Fix: add glibc-compat-static.c with a 32-bit off_t mmap()/mmap64() wrapper that goes straight to SYS_mmap2 bypassing musl's libc wrapper. Same pattern as #2000 (uclibc-compat-static for hi3516cv100). The function must be statically linked into the consumer executable (not in a .so) so the dynamic linker resolves vendor .so imports of mmap to the executable's symbol table BEFORE musl — putting it in a .so would override musl process-wide and break musl's own internal mmap callers (malloc, dlopen, etc.). - glibc-compat/src/glibc-compat-static.c: new file, mmap()/mmap64() wrappers calling SYS_mmap2 with pgoff - glibc-compat/src/Makefile: build both libglibc-compat.so and libglibc-compat-static.a - glibc-compat/glibc-compat.mk: INSTALL_STAGING=YES, install .a to STAGING_DIR so dependent packages can link -lglibc-compat-static - Makefile (BUNDLE_SDK): produce libglibc-compat.so and libglibc-compat-static.a in the published toolchain SDK tarball, mirroring the existing uclibc-compat handling Verified on lab DVR (openipc-hi3520dv200.dlab.torturelabs.com): linking dvr_home with the mmap shim makes HI_MPI_VENC_CreateChn succeed on all 4 channels. Refs: #1992 (toolchain ABI audit), #1993 (cv100 stat shim), #2000 (cv100 static-link split)
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Problem
libuclibc-compat.soexportedstat/mmapwhich overrode musl's implementations process-wide, causing segfaults. musl expects 64-bitoff_tfor mmap but the shim's version takesuint32_t— when musl's own internal code called mmap, it hit the wrong implementation.Confirmed crash: majestic segfaults at
hisi_free_mem_ex(MMZ memory allocation via mmap) on hi3516cv100 nightly build.Fix
Split into two libraries:
libuclibc-compat.so: only symbols MISSING from musl (__ctype_b,__assert,__fgetc_unlocked,memcpy_s, etc). Safe as shared lib — no conflict.libuclibc-compat-static.a:stat/mmapwrappers. Must be statically linked into the executable, so overrides only affect vendor.solookups through the executable's symbol scope, not musl internally.BUNDLE_SDKupdated to build and include both in the toolchain tarball.Test plan
.sohas no stat/mmap,.ahas them-luclibc-compat(dynamic) +-luclibc-compat-static(static)Ref: #1992