I'm going to move SYSENTER_stack to the beginning of cpu_tss to help
detect overflow. Before this can happen, I need to fix several code
paths that hardcode assumptions about the old layout.
Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
arch/x86/include/asm/desc.h | 2 +-
arch/x86/include/asm/processor.h | 4 ++--
arch/x86/kernel/cpu/common.c | 4 ++--
arch/x86/kernel/doublefault.c | 36 +++++++++++++++++-------------------
arch/x86/power/cpu.c | 13 +++++++------
5 files changed, 29 insertions(+), 30 deletions(-)
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 92ad5c354d11..ad35544d9e00 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -177,7 +177,7 @@ static inline void set_tssldt_descriptor(void *d, unsigned
long addr,
#endif
}
-static inline void __set_tss_desc(unsigned cpu, unsigned int entry, void *addr)
+static inline void __set_tss_desc(unsigned cpu, unsigned int entry, struct
x86_hw_tss *addr)
{
struct desc_struct *d = get_cpu_gdt_rw(cpu);
tss_desc tss;
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 0644f888b12c..301d41ca1fa1 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -161,7 +161,7 @@ enum cpuid_regs_idx {
extern struct cpuinfo_x86 boot_cpu_data;
extern struct cpuinfo_x86 new_cpu_data;
-extern struct tss_struct doublefault_tss;
+extern struct x86_hw_tss doublefault_tss;
extern __u32 cpu_caps_cleared[NCAPINTS];
extern __u32 cpu_caps_set[NCAPINTS];
@@ -321,7 +321,7 @@ struct x86_hw_tss {
#define IO_BITMAP_BITS 65536
#define IO_BITMAP_BYTES (IO_BITMAP_BITS/8)
#define IO_BITMAP_LONGS (IO_BITMAP_BYTES/sizeof(long))
-#define IO_BITMAP_OFFSET offsetof(struct tss_struct, io_bitmap)
+#define IO_BITMAP_OFFSET (offsetof(struct tss_struct, io_bitmap)
- offsetof(struct tss_struct, x86_tss))
#define INVALID_IO_BITMAP_OFFSET 0x8000
struct tss_struct {
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 2cb394dc4153..ce3b3c79fc0c 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1576,7 +1576,7 @@ void cpu_init(void)
* Initialize the TSS. Don't bother initializing sp0, as the initial
* task never enters user mode.
*/
- set_tss_desc(cpu, t);
+ set_tss_desc(cpu, &t->x86_tss);
load_TR_desc();
load_mm_ldt(&init_mm);
@@ -1634,7 +1634,7 @@ void cpu_init(void)
* Initialize the TSS. Don't bother initializing sp0, as the initial
* task never enters user mode.
*/
- set_tss_desc(cpu, t);
+ set_tss_desc(cpu, &t->x86_tss);
load_TR_desc();
load_mm_ldt(&init_mm);
diff --git a/arch/x86/kernel/doublefault.c b/arch/x86/kernel/doublefault.c
index f9c324e08d85..a9fe79d49d39 100644
--- a/arch/x86/kernel/doublefault.c
+++ b/arch/x86/kernel/doublefault.c
@@ -49,25 +49,23 @@ static void doublefault_fn(void)
cpu_relax();
}
-struct tss_struct doublefault_tss __cacheline_aligned = {
- .x86_tss = {
- .sp0 = STACK_START,
- .ss0 = __KERNEL_DS,
- .ldt = 0,
- .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
-
- .ip = (unsigned long) doublefault_fn,
- /* 0x2 bit is always set */
- .flags = X86_EFLAGS_SF | 0x2,
- .sp = STACK_START,
- .es = __USER_DS,
- .cs = __KERNEL_CS,
- .ss = __KERNEL_DS,
- .ds = __USER_DS,
- .fs = __KERNEL_PERCPU,
-
- .__cr3 = __pa_nodebug(swapper_pg_dir),
- }
+struct x86_hw_tss doublefault_tss __cacheline_aligned = {
+ .sp0 = STACK_START,
+ .ss0 = __KERNEL_DS,
+ .ldt = 0,
+ .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
+
+ .ip = (unsigned long) doublefault_fn,
+ /* 0x2 bit is always set */
+ .flags = X86_EFLAGS_SF | 0x2,
+ .sp = STACK_START,
+ .es = __USER_DS,
+ .cs = __KERNEL_CS,
+ .ss = __KERNEL_DS,
+ .ds = __USER_DS,
+ .fs = __KERNEL_PERCPU,
+
+ .__cr3 = __pa_nodebug(swapper_pg_dir),
};
/* dummy for do_double_fault() call */
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 84fcfde53f8f..50593e138281 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -165,12 +165,13 @@ static void fix_processor_context(void)
struct desc_struct *desc = get_cpu_gdt_rw(cpu);
tss_desc tss;
#endif
- set_tss_desc(cpu, t); /*
- * This just modifies memory; should not be
- * necessary. But... This is necessary, because
- * 386 hardware has concept of busy TSS or some
- * similar stupidity.
- */
+
+ /*
+ * This just modifies memory; should not be necessary. But... This is
+ * necessary, because 386 hardware has concept of busy TSS or some
+ * similar stupidity.
+ */
+ set_tss_desc(cpu, &t->x86_tss);
#ifdef CONFIG_X86_64
memcpy(&tss, &desc[GDT_ENTRY_TSS], sizeof(tss_desc));
--
2.13.6
