From: Hannes Domani <ssbssa@yahoo.de>
Date: Wed, 6 Dec 2023 19:52:06 +0000 (+0100)
Subject: Fix DLL export forwarding
X-Git-Tag: binutils-2_42~692
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2574cd903dd84e7081506e24c2e232ecda11a736;p=thirdparty%2Fbinutils-gdb.git

Fix DLL export forwarding

I noticed it when I was trying to set a breakpoint at ExitProcess:
```
(gdb) b ExitProcess
Breakpoint 1 at 0x14001fdd0
(gdb) r
Starting program: C:\qiewer\heob\heob64.exe
Warning:
Cannot insert breakpoint 1.
Cannot access memory at address 0x3dbf4120
Cannot insert breakpoint 1.
Cannot access memory at address 0x77644120
```

The problem doesn't exist in gdb 13.2, and the difference can easily be
seen when printing ExitProcess.
gdb 14.1:
```
(gdb) p ExitProcess
$1 = {<text variable, no debug info>} 0x77644120 <UserHandleGrantAccess+36128>
```
gdb 13.2:
```
(gdb) p ExitProcess
$1 = {<text variable, no debug info>} 0x77734120 <ntdll!RtlExitUserProcess>
```

The new behavior started with 9675da25357c7a3f472731ddc6eb3becc65b469a,
where VMA was then calculated relative to FORWARD_DLL_NAME, while it was
relative to DLL_NAME before.

Fixed by calculating VMA relative to DLL_NAME again.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31112
Approved-By: Tom Tromey <tom@tromey.com>
---

diff --git a/gdb/coff-pe-read.c b/gdb/coff-pe-read.c
index 56137ac4dd0..8e30c6a4a61 100644
--- a/gdb/coff-pe-read.c
+++ b/gdb/coff-pe-read.c
@@ -210,7 +210,10 @@ add_pe_forwarded_sym (minimal_symbol_reader &reader,
 			      " \"%s\" in dll \"%s\", pointing to \"%s\"\n"),
 		sym_name, dll_name, forward_qualified_name.c_str ());
 
-  unrelocated_addr vma = msymbol.minsym->unrelocated_address ();
+  /* Calculate VMA as if it were relative to DLL_NAME/OBJFILE, even though
+     it actually points inside another dll (FORWARD_DLL_NAME).  */
+  unrelocated_addr vma = unrelocated_addr (msymbol.value_address ()
+					   - objfile->text_section_offset ());
   msymtype = msymbol.minsym->type ();
   section = msymbol.minsym->section_index ();