Commit cf6f196d authored by Jason Wessel's avatar Jason Wessel
Browse files

kgdb,i386: Fix corner case access to ss with NMI watch dog exception

It is possible for the user_mode_vm(regs) check to return true on the
i368 arch for a non master kgdb cpu or when the master kgdb cpu
handles the NMI watch dog exception.

The solution is simply to select the correct gdb_ss location
based on the check to user_mode_vm(regs).

CC: Ingo Molnar <>
Acked-by: default avatarH. Peter Anvin <>
Signed-off-by: default avatarJason Wessel <>
parent 59d309f9
......@@ -86,9 +86,15 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
gdb_regs[GDB_DS] = regs->ds;
gdb_regs[GDB_ES] = regs->es;
gdb_regs[GDB_CS] = regs->cs;
gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_FS] = 0xFFFF;
gdb_regs[GDB_GS] = 0xFFFF;
if (user_mode_vm(regs)) {
gdb_regs[GDB_SS] = regs->ss;
gdb_regs[GDB_SP] = regs->sp;
} else {
gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_SP] = kernel_stack_pointer(regs);
gdb_regs[GDB_R8] = regs->r8;
gdb_regs[GDB_R9] = regs->r9;
......@@ -101,8 +107,8 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
gdb_regs32[GDB_PS] = regs->flags;
gdb_regs32[GDB_CS] = regs->cs;
gdb_regs32[GDB_SS] = regs->ss;
gdb_regs[GDB_SP] = kernel_stack_pointer(regs);
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