As early_trap_init() doesn't use IST, replace set_intr_gate_ist(..., 0)
and set_system_intr_gate_ist(..., 0) with their standard counterparts.
set_intr_gate() requires a trace_debug symbol which we don't have and
won't use. Use a small macro trick as a workaround.
Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
---
Hi Andy Lutomirski,
This patch is a bit tricky, but I think we don't need to define another
helper for such a small problem. What's your opinion?
Thank you!
---
arch/x86/kernel/traps.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 4281988..c24434a 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -925,17 +925,22 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
/* Set of traps needed for early debugging. */
void __init early_trap_init(void)
{
+
/*
- * Don't set ist to DEBUG_STACK as it doesn't work until TSS is
- * ready in cpu_init() <-- trap_init(). Before trap_init(), CPU
- * runs at ring 0 so it is impossible to hit an invalid stack.
- * Using the original stack works well enough at this early
- * stage. DEBUG_STACK will be equipped after cpu_init() in
- * trap_init().
+ * Don't use IST to set DEBUG_STACK as it doesn't work until TSS is
+ * ready in cpu_init() <-- trap_init(). Before trap_init(), CPU runs at
+ * ring 0 so it is impossible to hit an invalid stack. Using the
+ * original stack works well enough at this early stage. DEBUG_STACK
+ * will be equipped after cpu_init() in trap_init().
+ *
+ * Since set_intr_gate() needs a trace_debug but we don't have it,
+ * use the following #define as a workaround.
*/
- set_intr_gate_ist(X86_TRAP_DB, &debug, 0);
+#define trace_debug debug
+ set_intr_gate(X86_TRAP_DB, debug);
+#undef trace_debug
/* int3 can be called from all */
- set_system_intr_gate_ist(X86_TRAP_BP, &int3, 0);
+ set_system_intr_gate(X86_TRAP_BP, &int3);
#ifdef CONFIG_X86_32
set_intr_gate(X86_TRAP_PF, page_fault);
#endif
@@ -1015,7 +1020,7 @@ void __init trap_init(void)
/*
* X86_TRAP_DB and X86_TRAP_BP have been set
- * in early_trap_init(). However, DEBUG_STACK works only after
+ * in early_trap_init(). However, ITS works only after
* cpu_init() loads TSS. See comments in early_trap_init().
*/
set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK);
--
1.8.4
--
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