renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-18 18:23:53 +08:00
Code

x86: Rename variables for debugging

Browse Source 
Rename variables for debugging to describe meaning of them precisely.

Also, introduce a generic way to switch IDT by checking a current state,
debug on/off.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/51C323A8.7050905@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Seiji Aguchi 2013-06-20 11:45:44 -04:00 committed by H. Peter Anvin
parent eddc0e922a
commit 629f4f9d59
4 changed files with 54 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
arch/x86/include/asm/desc.h
View File

@ -36,8 +36,8 @@ static inline void fill_ldt(struct desc_struct *desc, const struct user_desc *in
extern struct desc_ptr idt_descr;
extern gate_desc idt_table[];
extern struct desc_ptr nmi_idt_descr;
extern gate_desc nmi_idt_table[];
extern struct desc_ptr debug_idt_descr;
extern gate_desc debug_idt_table[];
struct gdt_page {
struct desc_struct gdt[GDT_ENTRIES];
@ -316,7 +316,7 @@ static inline void set_nmi_gate(int gate, void *addr)
gate_desc s;
pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS);
write_idt_entry(nmi_idt_table, gate, &s);
write_idt_entry(debug_idt_table, gate, &s);
}
#endif
@ -405,4 +405,45 @@ static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
_set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
}
#ifdef CONFIG_X86_64
DECLARE_PER_CPU(u32, debug_idt_ctr);
static inline bool is_debug_idt_enabled(void)
{
if (this_cpu_read(debug_idt_ctr))
return true;
return false;
}
static inline void load_debug_idt(void)
{
load_idt((const struct desc_ptr *)&debug_idt_descr);
}
#else
static inline bool is_debug_idt_enabled(void)
{
return false;
}
static inline void load_debug_idt(void)
{
}
#endif
/*
* the load_current_idt() is called with interrupt disabled by local_irq_save()
* to avoid races. That way the IDT will always be set back to the expected
* descriptor.
*/
static inline void load_current_idt(void)
{
unsigned long flags;
local_irq_save(flags);
if (is_debug_idt_enabled())
load_debug_idt();
else
load_idt((const struct desc_ptr *)&idt_descr);
local_irq_restore(flags);
}
#endif /* _ASM_X86_DESC_H */

16
arch/x86/kernel/cpu/common.c
View File

@ -1071,8 +1071,8 @@ __setup("clearcpuid=", setup_disablecpuid);
#ifdef CONFIG_X86_64
struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
struct desc_ptr nmi_idt_descr = { NR_VECTORS * 16 - 1,
(unsigned long) nmi_idt_table };
struct desc_ptr debug_idt_descr = { NR_VECTORS * 16 - 1,
(unsigned long) debug_idt_table };
DEFINE_PER_CPU_FIRST(union irq_stack_union,
irq_stack_union) __aligned(PAGE_SIZE);
@ -1148,20 +1148,20 @@ int is_debug_stack(unsigned long addr)
addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ));
}
static DEFINE_PER_CPU(u32, debug_stack_use_ctr);
DEFINE_PER_CPU(u32, debug_idt_ctr);
void debug_stack_set_zero(void)
{
this_cpu_inc(debug_stack_use_ctr);
load_idt((const struct desc_ptr *)&nmi_idt_descr);
this_cpu_inc(debug_idt_ctr);
load_current_idt();
}
void debug_stack_reset(void)
{
if (WARN_ON(!this_cpu_read(debug_stack_use_ctr)))
if (WARN_ON(!this_cpu_read(debug_idt_ctr)))
return;
if (this_cpu_dec_return(debug_stack_use_ctr) == 0)
load_idt((const struct desc_ptr *)&idt_descr);
if (this_cpu_dec_return(debug_idt_ctr) == 0)
load_current_idt();
}
#else /* CONFIG_X86_64 */

2
arch/x86/kernel/head_64.S
View File

@ -518,7 +518,7 @@ ENTRY(idt_table)
.skip IDT_ENTRIES * 16
.align L1_CACHE_BYTES
ENTRY(nmi_idt_table)
ENTRY(debug_idt_table)
.skip IDT_ENTRIES * 16
__PAGE_ALIGNED_BSS

2
arch/x86/kernel/traps.c
View File

@ -785,7 +785,7 @@ void __init trap_init(void)
x86_init.irqs.trap_init();
#ifdef CONFIG_X86_64
memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16);
memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
set_nmi_gate(X86_TRAP_DB, &debug);
set_nmi_gate(X86_TRAP_BP, &int3);
#endif