From cf6f196d112a6f6757b1ca3cce0b576f7abee479 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 11 Dec 2009 08:43:16 -0600 Subject: [PATCH] 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: H. Peter Anvin Signed-off-by: Jason Wessel --- arch/x86/kernel/kgdb.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index f93d015753c..aefae46aa64 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -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); + } #else 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; -#endif gdb_regs[GDB_SP] = kernel_stack_pointer(regs); +#endif } /** -- 2.11.4.GIT