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[PULL,04/12] gdb-xml: Fix size of EFER register on i386 architecture when debugged by GDB

Message ID 20221106085115.257018-5-pbonzini@redhat.com (mailing list archive)
State New, archived
Headers show
Series [PULL,01/12] util/main-loop: Fix maximum number of wait objects for win32 | expand

Commit Message

Paolo Bonzini Nov. 6, 2022, 8:51 a.m. UTC 
From: TaiseiIto <taisei1212@outlook.jp>

Before this commit, there were contradictory descriptions about size of EFER
register.
Line 113 says the size is 8 bytes.
Line 129 says the size is 4 bytes.

As a result, when GDB is debugging an OS running on QEMU, the GDB cannot
read 'g' packets correctly. This 'g' packet transmits values of each
registers of machine emulated by QEMU to GDB. QEMU, the packet sender,
assign 4 bytes for EFER in 'g' packet based on the line 113.
GDB, the packet receiver, extract 8 bytes for EFER in 'g' packet based on
the line 129. Therefore, all registers located behind EFER in 'g' packet
has been shifted 4 bytes in GDB.

After this commit, GDB can read 'g' packets correctly.

Signed-off-by: TaiseiIto <taisei1212@outlook.jp>
Message-Id: <TY0PR0101MB4285F637209075C9F65FCDA6A4479@TY0PR0101MB4285.apcprd01.prod.exchangelabs.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 gdb-xml/i386-32bit.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/gdb-xml/i386-32bit.xml b/gdb-xml/i386-32bit.xml
index 872fcea9c25a..7a66a02b67e3 100644
--- a/gdb-xml/i386-32bit.xml
+++ b/gdb-xml/i386-32bit.xml
@@ -110,7 +110,7 @@ 
 	<field name="PKE" start="22" end="22"/>
   </flags>
 
-  <flags id="i386_efer" size="8">
+  <flags id="i386_efer" size="4">
 	<field name="TCE" start="15" end="15"/>
 	<field name="FFXSR" start="14" end="14"/>
 	<field name="LMSLE" start="13" end="13"/>