diff options
Diffstat (limited to 'patches/musl/1.1.3/0002-fix_mips_linker_regression.patch')
| -rw-r--r-- | patches/musl/1.1.3/0002-fix_mips_linker_regression.patch | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/patches/musl/1.1.3/0002-fix_mips_linker_regression.patch b/patches/musl/1.1.3/0002-fix_mips_linker_regression.patch deleted file mode 100644 index 4891b4f..0000000 --- a/patches/musl/1.1.3/0002-fix_mips_linker_regression.patch +++ /dev/null @@ -1,88 +0,0 @@ -From 2d8cc92a7cb4a3256ed07d86843388ffd8a882b1 Mon Sep 17 00:00:00 2001 -From: Rich Felker <dalias@aerifal.cx> -Date: Mon, 30 Jun 2014 05:18:14 +0000 -Subject: fix regression in mips dynamic linker - -this issue caused the address of functions in shared libraries to -resolve to their PLT thunks in the main program rather than their -correct addresses. it was observed causing crashes, though the -mechanism of the crash was not thoroughly investigated. since the -issue is very subtle, it calls for some explanation: - -on all well-behaved archs, GOT entries that belong to the PLT use a -special relocation type, typically called JMP_SLOT, so that the -dynamic linker can avoid having the jump destinations for the PLT -resolve to PLT thunks themselves (they also provide a definition for -the symbol, which must be used whenever the address of the function is -taken so that all DSOs see the same address). - -however, the traditional mips PIC ABI lacked such a JMP_SLOT -relocation type, presumably because, due to the way PIC works, the -address of the PLT thunk was never needed and could always be ignored. - -prior to commit adf94c19666e687a728bbf398f9a88ea4ea19996, the mips -version of reloc.h contained a hack that caused all symbol lookups to -be treated like JMP_SLOT, inhibiting undefined symbols from ever being -used to resolve symbolic relocations. this hack goes all the way back -to commit babf820180368f00742ec65b2050a82380d7c542, when the mips -dynamic linker was first made usable. - -during the recent refactoring to eliminate arch-specific relocation -processing (commit adf94c19666e687a728bbf398f9a88ea4ea19996), this -hack was overlooked and no equivalent functionality was provided in -the new code. - -fixing the problem is not as simple as adding back an equivalent hack, -since there is now also a "non-PIC ABI" that can be used for the main -executable, which actually does use a PLT. the closest thing to -official documentation I could find for this ABI is nonpic.txt, -attached to Message-ID: 20080701202236.GA1534@caradoc.them.org, which -can be found in the gcc mailing list archives and elsewhere. per this -document, undefined symbols corresponding to PLT thunks have the -STO_MIPS_PLT bit set in the symbol's st_other field. thus, I have -added an arch-specific rule for mips, applied at the find_sym level -rather than the relocation level, to reject undefined symbols with the -STO_MIPS_PLT bit clear. - -the previous hack of treating all mips relocations as JMP_SLOT-like, -rather than rejecting the unwanted symbols in find_sym, probably also -caused dlsym to wrongly return PLT thunks in place of the correct -address of a function under at least some conditions. this should now -be fixed, at least for global-scope symbol lookups. ---- -diff --git a/arch/mips/reloc.h b/arch/mips/reloc.h -index 91fa097..4b81d32 100644 ---- a/arch/mips/reloc.h -+++ b/arch/mips/reloc.h -@@ -86,3 +86,4 @@ static void do_arch_relocs(struct dso *this, struct dso *head) - - #define NEED_ARCH_RELOCS 1 - #define DYNAMIC_IS_RO 1 -+#define ARCH_SYM_REJECT_UND(s) (!((s)->st_other & STO_MIPS_PLT)) -diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c -index a08300d..55124ff 100644 ---- a/src/ldso/dynlink.c -+++ b/src/ldso/dynlink.c -@@ -233,6 +233,10 @@ static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso) - #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS) - #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE) - -+#ifndef ARCH_SYM_REJECT_UND -+#define ARCH_SYM_REJECT_UND(s) 0 -+#endif -+ - static struct symdef find_sym(struct dso *dso, const char *s, int need_def) - { - uint32_t h = 0, gh = 0; -@@ -249,7 +253,8 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def) - } - if (!sym) continue; - if (!sym->st_shndx) -- if (need_def || (sym->st_info&0xf) == STT_TLS) -+ if (need_def || (sym->st_info&0xf) == STT_TLS -+ || ARCH_SYM_REJECT_UND(sym)) - continue; - if (!sym->st_value) - if ((sym->st_info&0xf) != STT_TLS) --- -cgit v0.9.0.3-65-g4555 |