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| author | Ben Gamari <ben@smart-cactus.org> | 2020-09-30 23:41:40 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@well-typed.com> | 2021-10-06 08:47:38 +0000 |
| commit | bbaf9457d261efb072746d595d6b990984de112f (patch) | |
| tree | f45b419f35ddacfc3beb88a0d56e8353b0f1a546 | |
| parent | d510ade8b5fa9ee9686a5d4e9707876cb4602b9d (diff) | |
| download | haskell-bbaf9457d261efb072746d595d6b990984de112f.tar.gz | |
rts/linker: Define _DYNAMIC when necessary
Usually the dynamic linker would define _DYNAMIC. However, when dynamic
linking is not supported (e.g. on musl) it is safe to define it to be
NULL.
| -rw-r--r-- | rts/Linker.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/rts/Linker.c b/rts/Linker.c index 2641a677be..bff0b79b0c 100644 --- a/rts/Linker.c +++ b/rts/Linker.c @@ -869,7 +869,19 @@ SymbolAddr* lookupDependentSymbol (SymbolName* lbl, ObjectCode *dependent) IF_DEBUG(linker, debugBelch("lookupSymbol: symbol '%s' not found, trying dlsym\n", lbl)); # if defined(OBJFORMAT_ELF) - return internal_dlsym(lbl); + SymbolAddr *ret = internal_dlsym(lbl); + + // Generally the dynamic linker would define _DYNAMIC, which is + // supposed to point to various bits of dynamic linker state (see + // [1]). However, if dynamic linking isn't supported (e.g. in the case + // of musl) then we can safely declare that it is NULL. + // + // [1] https://wiki.gentoo.org/wiki/Hardened/Introduction_to_Position_Independent_Code + if (ret == NULL && strcmp(lbl, "_DYNAMIC") == 0) { + static void *RTS_DYNAMIC = NULL; + ret = (SymbolAddr *) &RTS_DYNAMIC; + } + return ret; # elif defined(OBJFORMAT_MACHO) /* HACK: On OS X, all symbols are prefixed with an underscore. |