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authorThomas Gleixner2019-04-14 17:59:52 +0200
committerBorislav Petkov2019-04-17 13:05:06 +0200
commitafcd21dad88b68d646e91ed36948117d58b4c197 (patch)
tree4bde9196c67725833b42a89adedf52296657cb57 /arch/x86/kernel
parentbf5882abab773afd1277415e2f826b21de28f30d (diff)
x86/dumpstack/64: Use cpu_entry_area instead of orig_ist
The orig_ist[] array is a shadow copy of the IST array in the TSS. The reason why it exists is that older kernels used two TSS variants with different pointers into the debug stack. orig_ist[] contains the real starting points. There is no point anymore to do so because the same information can be retrieved using the base address of the cpu entry area mapping and the offsets of the various exception stacks. No functional change. Preparation for removing orig_ist. Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190414160144.974900463@linutronix.de
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/dumpstack_64.c39
1 files changed, 27 insertions, 12 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 455b47ef9250..f6fbd0438f9e 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -16,6 +16,7 @@
#include <linux/bug.h>
#include <linux/nmi.h>
+#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
static const char *exception_stack_names[N_EXCEPTION_STACKS] = {
@@ -25,11 +26,6 @@ static const char *exception_stack_names[N_EXCEPTION_STACKS] = {
[ ESTACK_MCE ] = "#MC",
};
-static const unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
- [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
- [ESTACK_DB] = DEBUG_STKSZ
-};
-
const char *stack_type_name(enum stack_type type)
{
BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
@@ -52,25 +48,44 @@ const char *stack_type_name(enum stack_type type)
return NULL;
}
+struct estack_layout {
+ unsigned int begin;
+ unsigned int end;
+};
+
+#define ESTACK_ENTRY(x) { \
+ .begin = offsetof(struct cea_exception_stacks, x## _stack), \
+ .end = offsetof(struct cea_exception_stacks, x## _stack_guard) \
+ }
+
+static const struct estack_layout layout[N_EXCEPTION_STACKS] = {
+ [ ESTACK_DF ] = ESTACK_ENTRY(DF),
+ [ ESTACK_NMI ] = ESTACK_ENTRY(NMI),
+ [ ESTACK_DB ] = ESTACK_ENTRY(DB),
+ [ ESTACK_MCE ] = ESTACK_ENTRY(MCE),
+};
+
static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
{
- unsigned long *begin, *end;
+ unsigned long estacks, begin, end, stk = (unsigned long)stack;
struct pt_regs *regs;
- unsigned k;
+ unsigned int k;
BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+ estacks = (unsigned long)__this_cpu_read(cea_exception_stacks);
+
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
- end = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k];
- begin = end - (exception_stack_sizes[k] / sizeof(long));
+ begin = estacks + layout[k].begin;
+ end = estacks + layout[k].end;
regs = (struct pt_regs *)end - 1;
- if (stack < begin || stack >= end)
+ if (stk < begin || stk >= end)
continue;
info->type = STACK_TYPE_EXCEPTION + k;
- info->begin = begin;
- info->end = end;
+ info->begin = (unsigned long *)begin;
+ info->end = (unsigned long *)end;
info->next_sp = (unsigned long *)regs->sp;
return true;