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author | Hans Wennborg <hans@hanshq.net> | 2019-02-06 10:22:11 +0000 |
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committer | Hans Wennborg <hans@hanshq.net> | 2019-02-06 10:22:11 +0000 |
commit | 5581990eb08ddd98e511041fca75a13971eeb6b4 (patch) | |
tree | b8887f9493fa6f222d330ad0e7e60d647d2f658a | |
parent | 35f4f2f7220a796ada2499e9ea49b7f9531040a4 (diff) | |
download | llvm-5581990eb08ddd98e511041fca75a13971eeb6b4.zip llvm-5581990eb08ddd98e511041fca75a13971eeb6b4.tar.gz llvm-5581990eb08ddd98e511041fca75a13971eeb6b4.tar.bz2 |
Merging r352016:
------------------------------------------------------------------------
r352016 | phosek | 2019-01-24 04:04:42 +0100 (Thu, 24 Jan 2019) | 12 lines
[libunwind] Don't abort if encoutering invalid .eh_frame_hdr
Recent Linux kernel release has introduced a bug as part of the ORC
rollout where the vDSO has a valid .eh_frame section, but it's missing
the .eh_frame_hdr section and GNU_EH_FRAME segment has zero size. This
causes libunwind to abort which breaks programs that use libunwind.
The other unwinder implementation (libgcc, non-gnu) instead silently
bail out unless being compiled as debug. This change modifies libunwind
to use the same strategy.
Differential Revision: https://reviews.llvm.org/D57081
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llvm-svn: 353287
-rw-r--r-- | libunwind/src/AddressSpace.hpp | 6 | ||||
-rw-r--r-- | libunwind/src/EHHeaderParser.hpp | 16 |
2 files changed, 14 insertions, 8 deletions
diff --git a/libunwind/src/AddressSpace.hpp b/libunwind/src/AddressSpace.hpp index 30ad359..49bb360 100644 --- a/libunwind/src/AddressSpace.hpp +++ b/libunwind/src/AddressSpace.hpp @@ -534,11 +534,11 @@ inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr, #endif cbdata->sects->dwarf_index_section = eh_frame_hdr_start; cbdata->sects->dwarf_index_section_length = phdr->p_memsz; - EHHeaderParser<LocalAddressSpace>::decodeEHHdr( + found_hdr = EHHeaderParser<LocalAddressSpace>::decodeEHHdr( *cbdata->addressSpace, eh_frame_hdr_start, phdr->p_memsz, hdrInfo); - cbdata->sects->dwarf_section = hdrInfo.eh_frame_ptr; - found_hdr = true; + if (found_hdr) + cbdata->sects->dwarf_section = hdrInfo.eh_frame_ptr; } } diff --git a/libunwind/src/EHHeaderParser.hpp b/libunwind/src/EHHeaderParser.hpp index 9bdaf55..6b3e7dea 100644 --- a/libunwind/src/EHHeaderParser.hpp +++ b/libunwind/src/EHHeaderParser.hpp @@ -36,7 +36,7 @@ public: uint8_t table_enc; }; - static void decodeEHHdr(A &addressSpace, pint_t ehHdrStart, pint_t ehHdrEnd, + static bool decodeEHHdr(A &addressSpace, pint_t ehHdrStart, pint_t ehHdrEnd, EHHeaderInfo &ehHdrInfo); static bool findFDE(A &addressSpace, pint_t pc, pint_t ehHdrStart, uint32_t sectionLength, @@ -53,12 +53,14 @@ private: }; template <typename A> -void EHHeaderParser<A>::decodeEHHdr(A &addressSpace, pint_t ehHdrStart, +bool EHHeaderParser<A>::decodeEHHdr(A &addressSpace, pint_t ehHdrStart, pint_t ehHdrEnd, EHHeaderInfo &ehHdrInfo) { pint_t p = ehHdrStart; uint8_t version = addressSpace.get8(p++); - if (version != 1) - _LIBUNWIND_ABORT("Unsupported .eh_frame_hdr version"); + if (version != 1) { + _LIBUNWIND_LOG0("Unsupported .eh_frame_hdr version"); + return false; + } uint8_t eh_frame_ptr_enc = addressSpace.get8(p++); uint8_t fde_count_enc = addressSpace.get8(p++); @@ -71,6 +73,8 @@ void EHHeaderParser<A>::decodeEHHdr(A &addressSpace, pint_t ehHdrStart, ? 0 : addressSpace.getEncodedP(p, ehHdrEnd, fde_count_enc, ehHdrStart); ehHdrInfo.table = p; + + return true; } template <typename A> @@ -102,7 +106,9 @@ bool EHHeaderParser<A>::findFDE(A &addressSpace, pint_t pc, pint_t ehHdrStart, pint_t ehHdrEnd = ehHdrStart + sectionLength; EHHeaderParser<A>::EHHeaderInfo hdrInfo; - EHHeaderParser<A>::decodeEHHdr(addressSpace, ehHdrStart, ehHdrEnd, hdrInfo); + if (!EHHeaderParser<A>::decodeEHHdr(addressSpace, ehHdrStart, ehHdrEnd, + hdrInfo)) + return false; size_t tableEntrySize = getTableEntrySize(hdrInfo.table_enc); pint_t tableEntry; |