[tip:x86/asm] sched/x86/32, kgdb: Don't use thread.ip in sleeping_thread_to_gdb_regs()

[tip-bot for Brian Gerst]

Commit-ID:  4e047aa7f267c3449b6d323510d35864829aca70
Gitweb:     http://git.kernel.org/tip/4e047aa7f267c3449b6d323510d35864829aca70
Author:     Brian Gerst <brgerst@xxxxxxxxx>
AuthorDate: Sat, 13 Aug 2016 12:38:16 -0400
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 24 Aug 2016 12:27:40 +0200

sched/x86/32, kgdb: Don't use thread.ip in sleeping_thread_to_gdb_regs()

Match 64-bit and set gdb_regs[GDB_PC] to zero.  thread.ip is always the
same point in the scheduler (except for newly forked processes), and will
be removed in a future patch.

Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1471106302-10159-2-git-send-email-brgerst@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kernel/kgdb.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 04cde52..fe649a5 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -172,7 +172,6 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
 	gdb_regs[GDB_ES]	= __KERNEL_DS;
 	gdb_regs[GDB_PS]	= 0;
 	gdb_regs[GDB_CS]	= __KERNEL_CS;
-	gdb_regs[GDB_PC]	= p->thread.ip;
 	gdb_regs[GDB_SS]	= __KERNEL_DS;
 	gdb_regs[GDB_FS]	= 0xFFFF;
 	gdb_regs[GDB_GS]	= 0xFFFF;
@@ -180,7 +179,6 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
 	gdb_regs32[GDB_PS]	= *(unsigned long *)(p->thread.sp + 8);
 	gdb_regs32[GDB_CS]	= __KERNEL_CS;
 	gdb_regs32[GDB_SS]	= __KERNEL_DS;
-	gdb_regs[GDB_PC]	= 0;
 	gdb_regs[GDB_R8]	= 0;
 	gdb_regs[GDB_R9]	= 0;
 	gdb_regs[GDB_R10]	= 0;
@@ -190,6 +188,7 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
 	gdb_regs[GDB_R14]	= 0;
 	gdb_regs[GDB_R15]	= 0;
 #endif
+	gdb_regs[GDB_PC]	= 0;
 	gdb_regs[GDB_SP]	= p->thread.sp;
 }