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-rw-r--r--arch/x86/include/asm/a.out-core.h2
-rw-r--r--arch/x86/include/asm/elf.h15
-rw-r--r--arch/x86/include/asm/mmu_context.h2
-rw-r--r--arch/x86/include/asm/percpu.h22
-rw-r--r--arch/x86/include/asm/processor.h6
-rw-r--r--arch/x86/include/asm/ptrace.h4
-rw-r--r--arch/x86/include/asm/segment.h9
-rw-r--r--arch/x86/include/asm/stackprotector.h96
-rw-r--r--arch/x86/include/asm/syscalls.h20
-rw-r--r--arch/x86/include/asm/system.h38
-rw-r--r--arch/x86/include/asm/traps.h2
-rw-r--r--arch/x86/include/asm/uaccess.h33
-rw-r--r--arch/x86/include/asm/uv/uv.h3
13 files changed, 222 insertions, 30 deletions
diff --git a/arch/x86/include/asm/a.out-core.h b/arch/x86/include/asm/a.out-core.h
index 3c601f8224be..bb70e397aa84 100644
--- a/arch/x86/include/asm/a.out-core.h
+++ b/arch/x86/include/asm/a.out-core.h
@@ -55,7 +55,7 @@ static inline void aout_dump_thread(struct pt_regs *regs, struct user *dump)
dump->regs.ds = (u16)regs->ds;
dump->regs.es = (u16)regs->es;
dump->regs.fs = (u16)regs->fs;
- savesegment(gs, dump->regs.gs);
+ dump->regs.gs = get_user_gs(regs);
dump->regs.orig_ax = regs->orig_ax;
dump->regs.ip = regs->ip;
dump->regs.cs = (u16)regs->cs;
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index f51a3ddde01a..83c1bc8d2e8a 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -112,7 +112,7 @@ extern unsigned int vdso_enabled;
* now struct_user_regs, they are different)
*/
-#define ELF_CORE_COPY_REGS(pr_reg, regs) \
+#define ELF_CORE_COPY_REGS_COMMON(pr_reg, regs) \
do { \
pr_reg[0] = regs->bx; \
pr_reg[1] = regs->cx; \
@@ -124,7 +124,6 @@ do { \
pr_reg[7] = regs->ds & 0xffff; \
pr_reg[8] = regs->es & 0xffff; \
pr_reg[9] = regs->fs & 0xffff; \
- savesegment(gs, pr_reg[10]); \
pr_reg[11] = regs->orig_ax; \
pr_reg[12] = regs->ip; \
pr_reg[13] = regs->cs & 0xffff; \
@@ -133,6 +132,18 @@ do { \
pr_reg[16] = regs->ss & 0xffff; \
} while (0);
+#define ELF_CORE_COPY_REGS(pr_reg, regs) \
+do { \
+ ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
+ pr_reg[10] = get_user_gs(regs); \
+} while (0);
+
+#define ELF_CORE_COPY_KERNEL_REGS(pr_reg, regs) \
+do { \
+ ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
+ savesegment(gs, pr_reg[10]); \
+} while (0);
+
#define ELF_PLATFORM (utsname()->machine)
#define set_personality_64bit() do { } while (0)
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 52948df9cd1d..f923203dc39a 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -79,7 +79,7 @@ do { \
#ifdef CONFIG_X86_32
#define deactivate_mm(tsk, mm) \
do { \
- loadsegment(gs, 0); \
+ lazy_load_gs(0); \
} while (0)
#else
#define deactivate_mm(tsk, mm) \
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 0b64af4f13ac..aee103b26d01 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -34,6 +34,12 @@
#define PER_CPU_VAR(var) per_cpu__##var
#endif /* SMP */
+#ifdef CONFIG_X86_64_SMP
+#define INIT_PER_CPU_VAR(var) init_per_cpu__##var
+#else
+#define INIT_PER_CPU_VAR(var) per_cpu__##var
+#endif
+
#else /* ...!ASSEMBLY */
#include <linux/stringify.h>
@@ -45,6 +51,22 @@
#define __percpu_arg(x) "%" #x
#endif
+/*
+ * Initialized pointers to per-cpu variables needed for the boot
+ * processor need to use these macros to get the proper address
+ * offset from __per_cpu_load on SMP.
+ *
+ * There also must be an entry in vmlinux_64.lds.S
+ */
+#define DECLARE_INIT_PER_CPU(var) \
+ extern typeof(per_cpu_var(var)) init_per_cpu_var(var)
+
+#ifdef CONFIG_X86_64_SMP
+#define init_per_cpu_var(var) init_per_cpu__##var
+#else
+#define init_per_cpu_var(var) per_cpu_var(var)
+#endif
+
/* For arch-specific code, we can use direct single-insn ops (they
* don't give an lvalue though). */
extern void __bad_percpu_size(void);
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index a6643f68fbb1..a0133838b67c 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -393,8 +393,14 @@ union irq_stack_union {
};
DECLARE_PER_CPU(union irq_stack_union, irq_stack_union);
+DECLARE_INIT_PER_CPU(irq_stack_union);
+
DECLARE_PER_CPU(char *, irq_stack_ptr);
+#else /* X86_64 */
+#ifdef CONFIG_CC_STACKPROTECTOR
+DECLARE_PER_CPU(unsigned long, stack_canary);
#endif
+#endif /* X86_64 */
extern void print_cpu_info(struct cpuinfo_x86 *);
extern unsigned int xstate_size;
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 6d34d954c228..e304b66abeea 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -28,7 +28,7 @@ struct pt_regs {
int xds;
int xes;
int xfs;
- /* int gs; */
+ int xgs;
long orig_eax;
long eip;
int xcs;
@@ -50,7 +50,7 @@ struct pt_regs {
unsigned long ds;
unsigned long es;
unsigned long fs;
- /* int gs; */
+ unsigned long gs;
unsigned long orig_ax;
unsigned long ip;
unsigned long cs;
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 1dc1b51ac623..14e0ed86a6f9 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -61,7 +61,7 @@
*
* 26 - ESPFIX small SS
* 27 - per-cpu [ offset to per-cpu data area ]
- * 28 - unused
+ * 28 - stack_canary-20 [ for stack protector ]
* 29 - unused
* 30 - unused
* 31 - TSS for double fault handler
@@ -95,6 +95,13 @@
#define __KERNEL_PERCPU 0
#endif
+#define GDT_ENTRY_STACK_CANARY (GDT_ENTRY_KERNEL_BASE + 16)
+#ifdef CONFIG_CC_STACKPROTECTOR
+#define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY * 8)
+#else
+#define __KERNEL_STACK_CANARY 0
+#endif
+
#define GDT_ENTRY_DOUBLEFAULT_TSS 31
/*
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index 36a700acaf2b..c2d742c6e15f 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -1,8 +1,54 @@
+/*
+ * GCC stack protector support.
+ *
+ * Stack protector works by putting predefined pattern at the start of
+ * the stack frame and verifying that it hasn't been overwritten when
+ * returning from the function. The pattern is called stack canary
+ * and unfortunately gcc requires it to be at a fixed offset from %gs.
+ * On x86_64, the offset is 40 bytes and on x86_32 20 bytes. x86_64
+ * and x86_32 use segment registers differently and thus handles this
+ * requirement differently.
+ *
+ * On x86_64, %gs is shared by percpu area and stack canary. All
+ * percpu symbols are zero based and %gs points to the base of percpu
+ * area. The first occupant of the percpu area is always
+ * irq_stack_union which contains stack_canary at offset 40. Userland
+ * %gs is always saved and restored on kernel entry and exit using
+ * swapgs, so stack protector doesn't add any complexity there.
+ *
+ * On x86_32, it's slightly more complicated. As in x86_64, %gs is
+ * used for userland TLS. Unfortunately, some processors are much
+ * slower at loading segment registers with different value when
+ * entering and leaving the kernel, so the kernel uses %fs for percpu
+ * area and manages %gs lazily so that %gs is switched only when
+ * necessary, usually during task switch.
+ *
+ * As gcc requires the stack canary at %gs:20, %gs can't be managed
+ * lazily if stack protector is enabled, so the kernel saves and
+ * restores userland %gs on kernel entry and exit. This behavior is
+ * controlled by CONFIG_X86_32_LAZY_GS and accessors are defined in
+ * system.h to hide the details.
+ */
+
#ifndef _ASM_STACKPROTECTOR_H
#define _ASM_STACKPROTECTOR_H 1
+#ifdef CONFIG_CC_STACKPROTECTOR
+
#include <asm/tsc.h>
#include <asm/processor.h>
+#include <asm/percpu.h>
+#include <asm/system.h>
+#include <asm/desc.h>
+#include <linux/random.h>
+
+/*
+ * 24 byte read-only segment initializer for stack canary. Linker
+ * can't handle the address bit shifting. Address will be set in
+ * head_32 for boot CPU and setup_per_cpu_areas() for others.
+ */
+#define GDT_STACK_CANARY_INIT \
+ [GDT_ENTRY_STACK_CANARY] = { { { 0x00000018, 0x00409000 } } },
/*
* Initialize the stackprotector canary value.
@@ -15,12 +61,9 @@ static __always_inline void boot_init_stack_canary(void)
u64 canary;
u64 tsc;
- /*
- * Build time only check to make sure the stack_canary is at
- * offset 40 in the pda; this is a gcc ABI requirement
- */
+#ifdef CONFIG_X86_64
BUILD_BUG_ON(offsetof(union irq_stack_union, stack_canary) != 40);
-
+#endif
/*
* We both use the random pool and the current TSC as a source
* of randomness. The TSC only matters for very early init,
@@ -32,7 +75,50 @@ static __always_inline void boot_init_stack_canary(void)
canary += tsc + (tsc << 32UL);
current->stack_canary = canary;
+#ifdef CONFIG_X86_64
percpu_write(irq_stack_union.stack_canary, canary);
+#else
+ percpu_write(stack_canary, canary);
+#endif
}
+static inline void setup_stack_canary_segment(int cpu)
+{
+#ifdef CONFIG_X86_32
+ unsigned long canary = (unsigned long)&per_cpu(stack_canary, cpu) - 20;
+ struct desc_struct *gdt_table = get_cpu_gdt_table(cpu);
+ struct desc_struct desc;
+
+ desc = gdt_table[GDT_ENTRY_STACK_CANARY];
+ desc.base0 = canary & 0xffff;
+ desc.base1 = (canary >> 16) & 0xff;
+ desc.base2 = (canary >> 24) & 0xff;
+ write_gdt_entry(gdt_table, GDT_ENTRY_STACK_CANARY, &desc, DESCTYPE_S);
+#endif
+}
+
+static inline void load_stack_canary_segment(void)
+{
+#ifdef CONFIG_X86_32
+ asm("mov %0, %%gs" : : "r" (__KERNEL_STACK_CANARY) : "memory");
+#endif
+}
+
+#else /* CC_STACKPROTECTOR */
+
+#define GDT_STACK_CANARY_INIT
+
+/* dummy boot_init_stack_canary() is defined in linux/stackprotector.h */
+
+static inline void setup_stack_canary_segment(int cpu)
+{ }
+
+static inline void load_stack_canary_segment(void)
+{
+#ifdef CONFIG_X86_32
+ asm volatile ("mov %0, %%gs" : : "r" (0));
#endif
+}
+
+#endif /* CC_STACKPROTECTOR */
+#endif /* _ASM_STACKPROTECTOR_H */
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index c0b0bda754ee..68b1be10cfad 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -29,21 +29,21 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *);
/* X86_32 only */
#ifdef CONFIG_X86_32
/* kernel/process_32.c */
-asmlinkage int sys_fork(struct pt_regs);
-asmlinkage int sys_clone(struct pt_regs);
-asmlinkage int sys_vfork(struct pt_regs);
-asmlinkage int sys_execve(struct pt_regs);
+int sys_fork(struct pt_regs *);
+int sys_clone(struct pt_regs *);
+int sys_vfork(struct pt_regs *);
+int sys_execve(struct pt_regs *);
/* kernel/signal_32.c */
asmlinkage int sys_sigsuspend(int, int, old_sigset_t);
asmlinkage int sys_sigaction(int, const struct old_sigaction __user *,
struct old_sigaction __user *);
-asmlinkage int sys_sigaltstack(unsigned long);
-asmlinkage unsigned long sys_sigreturn(unsigned long);
-asmlinkage int sys_rt_sigreturn(unsigned long);
+int sys_sigaltstack(struct pt_regs *);
+unsigned long sys_sigreturn(struct pt_regs *);
+long sys_rt_sigreturn(struct pt_regs *);
/* kernel/ioport.c */
-asmlinkage long sys_iopl(unsigned long);
+long sys_iopl(struct pt_regs *);
/* kernel/sys_i386_32.c */
asmlinkage long sys_mmap2(unsigned long, unsigned long, unsigned long,
@@ -59,8 +59,8 @@ struct oldold_utsname;
asmlinkage int sys_olduname(struct oldold_utsname __user *);
/* kernel/vm86_32.c */
-asmlinkage int sys_vm86old(struct pt_regs);
-asmlinkage int sys_vm86(struct pt_regs);
+int sys_vm86old(struct pt_regs *);
+int sys_vm86(struct pt_regs *);
#else /* CONFIG_X86_32 */
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index c22383743f36..c00bfdbdd456 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -23,6 +23,20 @@ struct task_struct *__switch_to(struct task_struct *prev,
#ifdef CONFIG_X86_32
+#ifdef CONFIG_CC_STACKPROTECTOR
+#define __switch_canary \
+ "movl %P[task_canary](%[next]), %%ebx\n\t" \
+ "movl %%ebx, "__percpu_arg([stack_canary])"\n\t"
+#define __switch_canary_oparam \
+ , [stack_canary] "=m" (per_cpu_var(stack_canary))
+#define __switch_canary_iparam \
+ , [task_canary] "i" (offsetof(struct task_struct, stack_canary))
+#else /* CC_STACKPROTECTOR */
+#define __switch_canary
+#define __switch_canary_oparam
+#define __switch_canary_iparam
+#endif /* CC_STACKPROTECTOR */
+
/*
* Saving eflags is important. It switches not only IOPL between tasks,
* it also protects other tasks from NT leaking through sysenter etc.
@@ -44,6 +58,7 @@ do { \
"movl %[next_sp],%%esp\n\t" /* restore ESP */ \
"movl $1f,%[prev_ip]\n\t" /* save EIP */ \
"pushl %[next_ip]\n\t" /* restore EIP */ \
+ __switch_canary \
"jmp __switch_to\n" /* regparm call */ \
"1:\t" \
"popl %%ebp\n\t" /* restore EBP */ \
@@ -58,6 +73,8 @@ do { \
"=b" (ebx), "=c" (ecx), "=d" (edx), \
"=S" (esi), "=D" (edi) \
\
+ __switch_canary_oparam \
+ \
/* input parameters: */ \
: [next_sp] "m" (next->thread.sp), \
[next_ip] "m" (next->thread.ip), \
@@ -66,6 +83,8 @@ do { \
[prev] "a" (prev), \
[next] "d" (next) \
\
+ __switch_canary_iparam \
+ \
: /* reloaded segment registers */ \
"memory"); \
} while (0)
@@ -182,6 +201,25 @@ extern void native_load_gs_index(unsigned);
#define savesegment(seg, value) \
asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
+/*
+ * x86_32 user gs accessors.
+ */
+#ifdef CONFIG_X86_32
+#ifdef CONFIG_X86_32_LAZY_GS
+#define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;})
+#define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v))
+#define task_user_gs(tsk) ((tsk)->thread.gs)
+#define lazy_save_gs(v) savesegment(gs, (v))
+#define lazy_load_gs(v) loadsegment(gs, (v))
+#else /* X86_32_LAZY_GS */
+#define get_user_gs(regs) (u16)((regs)->gs)
+#define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0)
+#define task_user_gs(tsk) (task_pt_regs(tsk)->gs)
+#define lazy_save_gs(v) do { } while (0)
+#define lazy_load_gs(v) do { } while (0)
+#endif /* X86_32_LAZY_GS */
+#endif /* X86_32 */
+
static inline unsigned long get_limit(unsigned long segment)
{
unsigned long __limit;
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index cf3bb053da0b..0d5342515b86 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -41,7 +41,7 @@ dotraplinkage void do_int3(struct pt_regs *, long);
dotraplinkage void do_overflow(struct pt_regs *, long);
dotraplinkage void do_bounds(struct pt_regs *, long);
dotraplinkage void do_invalid_op(struct pt_regs *, long);
-dotraplinkage void do_device_not_available(struct pt_regs);
+dotraplinkage void do_device_not_available(struct pt_regs *, long);
dotraplinkage void do_coprocessor_segment_overrun(struct pt_regs *, long);
dotraplinkage void do_invalid_TSS(struct pt_regs *, long);
dotraplinkage void do_segment_not_present(struct pt_regs *, long);
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 0ec6de4bcb0b..b685ece89d5c 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -186,7 +186,7 @@ extern int __get_user_bad(void);
#ifdef CONFIG_X86_32
-#define __put_user_asm_u64(x, addr, err) \
+#define __put_user_asm_u64(x, addr, err, errret) \
asm volatile("1: movl %%eax,0(%2)\n" \
"2: movl %%edx,4(%2)\n" \
"3:\n" \
@@ -197,7 +197,7 @@ extern int __get_user_bad(void);
_ASM_EXTABLE(1b, 4b) \
_ASM_EXTABLE(2b, 4b) \
: "=r" (err) \
- : "A" (x), "r" (addr), "i" (-EFAULT), "0" (err))
+ : "A" (x), "r" (addr), "i" (errret), "0" (err))
#define __put_user_asm_ex_u64(x, addr) \
asm volatile("1: movl %%eax,0(%1)\n" \
@@ -211,8 +211,8 @@ extern int __get_user_bad(void);
asm volatile("call __put_user_8" : "=a" (__ret_pu) \
: "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
#else
-#define __put_user_asm_u64(x, ptr, retval) \
- __put_user_asm(x, ptr, retval, "q", "", "Zr", -EFAULT)
+#define __put_user_asm_u64(x, ptr, retval, errret) \
+ __put_user_asm(x, ptr, retval, "q", "", "Zr", errret)
#define __put_user_asm_ex_u64(x, addr) \
__put_user_asm_ex(x, addr, "q", "", "Zr")
#define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu)
@@ -289,7 +289,8 @@ do { \
__put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \
break; \
case 8: \
- __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval); \
+ __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \
+ errret); \
break; \
default: \
__put_user_bad(); \
@@ -525,8 +526,6 @@ struct __large_struct { unsigned long buf[100]; };
*/
#define get_user_try uaccess_try
#define get_user_catch(err) uaccess_catch(err)
-#define put_user_try uaccess_try
-#define put_user_catch(err) uaccess_catch(err)
#define get_user_ex(x, ptr) do { \
unsigned long __gue_val; \
@@ -534,9 +533,29 @@ struct __large_struct { unsigned long buf[100]; };
(x) = (__force __typeof__(*(ptr)))__gue_val; \
} while (0)
+#ifdef CONFIG_X86_WP_WORKS_OK
+
+#define put_user_try uaccess_try
+#define put_user_catch(err) uaccess_catch(err)
+
#define put_user_ex(x, ptr) \
__put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+#else /* !CONFIG_X86_WP_WORKS_OK */
+
+#define put_user_try do { \
+ int __uaccess_err = 0;
+
+#define put_user_catch(err) \
+ (err) |= __uaccess_err; \
+} while (0)
+
+#define put_user_ex(x, ptr) do { \
+ __uaccess_err |= __put_user(x, ptr); \
+} while (0)
+
+#endif /* CONFIG_X86_WP_WORKS_OK */
+
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/
diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h
index 8ac1d7e312f3..8242bf965812 100644
--- a/arch/x86/include/asm/uv/uv.h
+++ b/arch/x86/include/asm/uv/uv.h
@@ -3,6 +3,9 @@
enum uv_system_type {UV_NONE, UV_LEGACY_APIC, UV_X2APIC, UV_NON_UNIQUE_APIC};
+struct cpumask;
+struct mm_struct;
+
#ifdef CONFIG_X86_UV
extern enum uv_system_type get_uv_system_type(void);
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-10 19:30:54 +0000