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Diffstat (limited to 'arch/x86/kernel/traps.c')
-rw-r--r--arch/x86/kernel/traps.c174
1 files changed, 99 insertions, 75 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index b481341c936..8276dc6794c 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -55,6 +55,7 @@
#include <asm/i387.h>
#include <asm/fpu-internal.h>
#include <asm/mce.h>
+#include <asm/rcu.h>
#include <asm/mach_traps.h>
@@ -107,30 +108,45 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
dec_preempt_count();
}
-static void __kprobes
-do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
- long error_code, siginfo_t *info)
+static int __kprobes
+do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
+ struct pt_regs *regs, long error_code)
{
- struct task_struct *tsk = current;
-
#ifdef CONFIG_X86_32
if (regs->flags & X86_VM_MASK) {
/*
- * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
+ * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
* On nmi (interrupt 2), do_trap should not be called.
*/
- if (trapnr < X86_TRAP_UD)
- goto vm86_trap;
- goto trap_signal;
+ if (trapnr < X86_TRAP_UD) {
+ if (!handle_vm86_trap((struct kernel_vm86_regs *) regs,
+ error_code, trapnr))
+ return 0;
+ }
+ return -1;
}
#endif
+ if (!user_mode(regs)) {
+ if (!fixup_exception(regs)) {
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_nr = trapnr;
+ die(str, regs, error_code);
+ }
+ return 0;
+ }
- if (!user_mode(regs))
- goto kernel_trap;
+ return -1;
+}
-#ifdef CONFIG_X86_32
-trap_signal:
-#endif
+static void __kprobes
+do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
+ long error_code, siginfo_t *info)
+{
+ struct task_struct *tsk = current;
+
+
+ if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code))
+ return;
/*
* We want error_code and trap_nr set for userspace faults and
* kernelspace faults which result in die(), but not
@@ -158,33 +174,20 @@ trap_signal:
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
- return;
-
-kernel_trap:
- if (!fixup_exception(regs)) {
- tsk->thread.error_code = error_code;
- tsk->thread.trap_nr = trapnr;
- die(str, regs, error_code);
- }
- return;
-
-#ifdef CONFIG_X86_32
-vm86_trap:
- if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
- error_code, trapnr))
- goto trap_signal;
- return;
-#endif
}
#define DO_ERROR(trapnr, signr, str, name) \
dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
{ \
- if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
- == NOTIFY_STOP) \
+ exception_enter(regs); \
+ if (notify_die(DIE_TRAP, str, regs, error_code, \
+ trapnr, signr) == NOTIFY_STOP) { \
+ exception_exit(regs); \
return; \
+ } \
conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, NULL); \
+ exception_exit(regs); \
}
#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
@@ -195,11 +198,15 @@ dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
info.si_errno = 0; \
info.si_code = sicode; \
info.si_addr = (void __user *)siaddr; \
- if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
- == NOTIFY_STOP) \
+ exception_enter(regs); \
+ if (notify_die(DIE_TRAP, str, regs, error_code, \
+ trapnr, signr) == NOTIFY_STOP) { \
+ exception_exit(regs); \
return; \
+ } \
conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, &info); \
+ exception_exit(regs); \
}
DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV,
@@ -222,12 +229,14 @@ DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check,
/* Runs on IST stack */
dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
{
+ exception_enter(regs);
if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
- X86_TRAP_SS, SIGBUS) == NOTIFY_STOP)
- return;
- preempt_conditional_sti(regs);
- do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL);
- preempt_conditional_cli(regs);
+ X86_TRAP_SS, SIGBUS) != NOTIFY_STOP) {
+ preempt_conditional_sti(regs);
+ do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL);
+ preempt_conditional_cli(regs);
+ }
+ exception_exit(regs);
}
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
@@ -235,6 +244,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
static const char str[] = "double fault";
struct task_struct *tsk = current;
+ exception_enter(regs);
/* Return not checked because double check cannot be ignored */
notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
@@ -255,16 +265,29 @@ do_general_protection(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk;
+ exception_enter(regs);
conditional_sti(regs);
#ifdef CONFIG_X86_32
- if (regs->flags & X86_VM_MASK)
- goto gp_in_vm86;
+ if (regs->flags & X86_VM_MASK) {
+ local_irq_enable();
+ handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
+ goto exit;
+ }
#endif
tsk = current;
- if (!user_mode(regs))
- goto gp_in_kernel;
+ if (!user_mode(regs)) {
+ if (fixup_exception(regs))
+ goto exit;
+
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_nr = X86_TRAP_GP;
+ if (notify_die(DIE_GPF, "general protection fault", regs, error_code,
+ X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP)
+ die("general protection fault", regs, error_code);
+ goto exit;
+ }
tsk->thread.error_code = error_code;
tsk->thread.trap_nr = X86_TRAP_GP;
@@ -279,25 +302,8 @@ do_general_protection(struct pt_regs *regs, long error_code)
}
force_sig(SIGSEGV, tsk);
- return;
-
-#ifdef CONFIG_X86_32
-gp_in_vm86:
- local_irq_enable();
- handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
- return;
-#endif
-
-gp_in_kernel:
- if (fixup_exception(regs))
- return;
-
- tsk->thread.error_code = error_code;
- tsk->thread.trap_nr = X86_TRAP_GP;
- if (notify_die(DIE_GPF, "general protection fault", regs, error_code,
- X86_TRAP_GP, SIGSEGV) == NOTIFY_STOP)
- return;
- die("general protection fault", regs, error_code);
+exit:
+ exception_exit(regs);
}
/* May run on IST stack. */
@@ -312,15 +318,16 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
ftrace_int3_handler(regs))
return;
#endif
+ exception_enter(regs);
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
SIGTRAP) == NOTIFY_STOP)
- return;
+ goto exit;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
SIGTRAP) == NOTIFY_STOP)
- return;
+ goto exit;
/*
* Let others (NMI) know that the debug stack is in use
@@ -331,6 +338,8 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
preempt_conditional_cli(regs);
debug_stack_usage_dec();
+exit:
+ exception_exit(regs);
}
#ifdef CONFIG_X86_64
@@ -391,6 +400,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
unsigned long dr6;
int si_code;
+ exception_enter(regs);
+
get_debugreg(dr6, 6);
/* Filter out all the reserved bits which are preset to 1 */
@@ -406,7 +417,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
/* Catch kmemcheck conditions first of all! */
if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
- return;
+ goto exit;
/* DR6 may or may not be cleared by the CPU */
set_debugreg(0, 6);
@@ -421,7 +432,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code,
SIGTRAP) == NOTIFY_STOP)
- return;
+ goto exit;
/*
* Let others (NMI) know that the debug stack is in use
@@ -437,7 +448,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
X86_TRAP_DB);
preempt_conditional_cli(regs);
debug_stack_usage_dec();
- return;
+ goto exit;
}
/*
@@ -458,7 +469,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
preempt_conditional_cli(regs);
debug_stack_usage_dec();
- return;
+exit:
+ exception_exit(regs);
}
/*
@@ -555,14 +567,17 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
#ifdef CONFIG_X86_32
ignore_fpu_irq = 1;
#endif
-
+ exception_enter(regs);
math_error(regs, error_code, X86_TRAP_MF);
+ exception_exit(regs);
}
dotraplinkage void
do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
{
+ exception_enter(regs);
math_error(regs, error_code, X86_TRAP_XF);
+ exception_exit(regs);
}
dotraplinkage void
@@ -613,11 +628,12 @@ void math_state_restore(void)
}
__thread_fpu_begin(tsk);
+
/*
* Paranoid restore. send a SIGSEGV if we fail to restore the state.
*/
if (unlikely(restore_fpu_checking(tsk))) {
- __thread_fpu_end(tsk);
+ drop_init_fpu(tsk);
force_sig(SIGSEGV, tsk);
return;
}
@@ -629,6 +645,9 @@ EXPORT_SYMBOL_GPL(math_state_restore);
dotraplinkage void __kprobes
do_device_not_available(struct pt_regs *regs, long error_code)
{
+ exception_enter(regs);
+ BUG_ON(use_eager_fpu());
+
#ifdef CONFIG_MATH_EMULATION
if (read_cr0() & X86_CR0_EM) {
struct math_emu_info info = { };
@@ -637,6 +656,7 @@ do_device_not_available(struct pt_regs *regs, long error_code)
info.regs = regs;
math_emulate(&info);
+ exception_exit(regs);
return;
}
#endif
@@ -644,12 +664,15 @@ do_device_not_available(struct pt_regs *regs, long error_code)
#ifdef CONFIG_X86_32
conditional_sti(regs);
#endif
+ exception_exit(regs);
}
#ifdef CONFIG_X86_32
dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
{
siginfo_t info;
+
+ exception_enter(regs);
local_irq_enable();
info.si_signo = SIGILL;
@@ -657,10 +680,11 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
info.si_code = ILL_BADSTK;
info.si_addr = NULL;
if (notify_die(DIE_TRAP, "iret exception", regs, error_code,
- X86_TRAP_IRET, SIGILL) == NOTIFY_STOP)
- return;
- do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
- &info);
+ X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) {
+ do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
+ &info);
+ }
+ exception_exit(regs);
}
#endif
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-04 11:53:51 +0000