rts: Refuse to create jump islands for symbols with info tableswip/T20983

When tables-next-to-code is enabled we must not relocate references to
info-table symbols using jump islands.

Fixes #20983.

2 files changed, 10 insertions, 0 deletions

diff --git a/rts/LinkerInternals.h b/rts/LinkerInternals.h
index 7058ad355b..cf78bd5e11 100644
--- a/rts/LinkerInternals.h
+++ b/rts/LinkerInternals.h
@@ -16,6 +16,9 @@
 #include <sys/mman.h>
 #endif
 
+/* See Note [Refuse to generate jump islands for _info symbols] */
+void isTntcSymbol(const char *);
+
 void printLoadedObjects(void);
 
 #include "BeginPrivate.h"
diff --git a/rts/linker/PEi386.c b/rts/linker/PEi386.c
index f186da0af8..8eb046a38e 100644
--- a/rts/linker/PEi386.c
+++ b/rts/linker/PEi386.c
@@ -1947,6 +1947,9 @@ ocResolve_PEi386 ( ObjectCode* oc )
                    // N.B. in the case of the sign-extended relocations we must ensure that v
                    // fits in a signed 32-bit value. See #15808.
                    if (((int64_t) v > (int64_t) INT32_MAX) || ((int64_t) v < (int64_t) INT32_MIN)) {
+                       if (isTntcSymbol(symbol)) {
+                           barf("Unable relocate symbol '%s' with info table as we would need to produce a jump island", symbol);
+                       }
                        copyName (getSymShortName (info, sym), oc,
                                  symbol, sizeof(symbol)-1);
                        S = makeSymbolExtra_PEi386(oc, symIndex, S, (char *)symbol);
@@ -1965,6 +1968,10 @@ ocResolve_PEi386 ( ObjectCode* oc )
                    intptr_t v;
                    v = S + (int32_t)A - ((intptr_t)pP) - 4;
                    if ((v > (int64_t) INT32_MAX) || (v < (int64_t) INT32_MIN)) {
+                       if (isTntcSymbol(symbol)) {
+                           barf("Unable relocate symbol '%s' with info table as we would need to produce a jump island", symbol);
+                       }
+
                        /* Make the trampoline then */
                        copyName (getSymShortName (info, sym),
                                  oc, symbol, sizeof(symbol)-1);