From 34f06334025521c2440ebedb0237697fbcc3c6de Mon Sep 17 00:00:00 2001
From: Moritz Angermann <moritz.angermann@gmail.com>
Date: Sat, 21 Oct 2023 14:35:12 +0800
Subject: [PATCH] [PEi386] Mask SYM_TYPE_DUP_DISCARD in makeSymbolExtra
48e391952c17ff7eab10b0b1456e3f2a2af28a9b
introduced `SYM_TYPE_DUP_DISCARD` to the bitfield.
The linker however, failed to mask the `SYM_TYPE_DUP_DISCARD` value.
Thus `== SYM_TYPE_CODE` comparisons easily failed. This lead to us
relocating DATA lookups (GOT) into E8 (call) and E9 (jump) instructions.
---
rts/linker/PEi386.c | 49 ++++++++++++++++++++++++---------------------
1 file changed, 26 insertions(+), 23 deletions(-)
diff --git a/rts/linker/PEi386.c b/rts/linker/PEi386.c
index 4ede63c1d35c..843f2a2c6445 100644
--- a/rts/linker/PEi386.c
+++ b/rts/linker/PEi386.c
@@ -1939,29 +1939,32 @@ static size_t
makeSymbolExtra_PEi386( ObjectCode* oc, uint64_t index STG_UNUSED, size_t s, char* symbol STG_UNUSED, SymType type )
{
SymbolExtra *extra;
-
- if (type == SYM_TYPE_CODE) {
- // jmp *-14(%rip)
- extra = m32_alloc(oc->rx_m32, sizeof(SymbolExtra), 8);
- CHECK(extra);
- extra->addr = (uint64_t)s;
- static uint8_t jmp[] = { 0xFF, 0x25, 0xF2, 0xFF, 0xFF, 0xFF };
- memcpy(extra->jumpIsland, jmp, 6);
- IF_DEBUG(linker_verbose, debugBelch("makeSymbolExtra(code): %s -> %p\n", symbol, &extra->jumpIsland));
- return (size_t)&extra->jumpIsland;
- } else if (type == SYM_TYPE_INDIRECT_DATA) {
- extra = m32_alloc(oc->rw_m32, sizeof(SymbolExtra), 8);
- CHECK(extra);
- void *v = *(void**) s;
- extra->addr = (uint64_t)v;
- IF_DEBUG(linker_verbose, debugBelch("makeSymbolExtra(data): %s -> %p\n", symbol, &extra->addr));
- return (size_t)&extra->addr;
- } else {
- extra = m32_alloc(oc->rw_m32, sizeof(SymbolExtra), 8);
- CHECK(extra);
- extra->addr = (uint64_t)s;
- IF_DEBUG(linker_verbose, debugBelch("makeSymbolExtra(indirect-data): %s -> %p\n", symbol, &extra->addr));
- return (size_t)&extra->addr;
+ switch(type & ~SYM_TYPE_DUP_DISCARD) {
+ case SYM_TYPE_CODE: {
+ // jmp *-14(%rip)
+ extra = m32_alloc(oc->rx_m32, sizeof(SymbolExtra), 8);
+ CHECK(extra);
+ extra->addr = (uint64_t)s;
+ static uint8_t jmp[] = { 0xFF, 0x25, 0xF2, 0xFF, 0xFF, 0xFF };
+ memcpy(extra->jumpIsland, jmp, 6);
+ IF_DEBUG(linker_verbose, debugBelch("makeSymbolExtra(code): %s -> %p\n", symbol, &extra->jumpIsland));
+ return (size_t)&extra->jumpIsland;
+ }
+ case SYM_TYPE_INDIRECT_DATA: {
+ extra = m32_alloc(oc->rw_m32, sizeof(SymbolExtra), 8);
+ CHECK(extra);
+ void *v = *(void**) s;
+ extra->addr = (uint64_t)v;
+ IF_DEBUG(linker_verbose, debugBelch("makeSymbolExtra(data): %s -> %p\n", symbol, &extra->addr));
+ return (size_t)&extra->addr;
+ }
+ default: {
+ extra = m32_alloc(oc->rw_m32, sizeof(SymbolExtra), 8);
+ CHECK(extra);
+ extra->addr = (uint64_t)s;
+ IF_DEBUG(linker_verbose, debugBelch("makeSymbolExtra(indirect-data): %s -> %p\n", symbol, &extra->addr));
+ return (size_t)&extra->addr;
+ }
}
}
--
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