aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/process_32.c3
-rw-r--r--arch/x86/kernel/process_64.c5
-rw-r--r--arch/x86/kernel/ptrace_32.c17
-rw-r--r--arch/x86/kernel/ptrace_64.c20
-rw-r--r--arch/x86/kernel/signal_32.c12
-rw-r--r--arch/x86/kernel/signal_64.c14
-rw-r--r--arch/x86/kernel/step.c9
-rw-r--r--arch/x86/kernel/traps_64.c23
8 files changed, 55 insertions, 48 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 4d66a56280d..d9905c9d0fd 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -817,9 +817,6 @@ asmlinkage int sys_execve(struct pt_regs regs)
(char __user * __user *) regs.edx,
&regs);
if (error == 0) {
- task_lock(current);
- current->ptrace &= ~PT_DTRACE;
- task_unlock(current);
/* Make sure we don't return using sysenter.. */
set_thread_flag(TIF_IRET);
}
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index ccc9d68d5a5..f7356e5517f 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -709,11 +709,6 @@ long sys_execve(char __user *name, char __user * __user *argv,
if (IS_ERR(filename))
return error;
error = do_execve(filename, argv, envp, &regs);
- if (error == 0) {
- task_lock(current);
- current->ptrace &= ~PT_DTRACE;
- task_unlock(current);
- }
putname(filename);
return error;
}
diff --git a/arch/x86/kernel/ptrace_32.c b/arch/x86/kernel/ptrace_32.c
index b73960885c3..bc7fd802dcc 100644
--- a/arch/x86/kernel/ptrace_32.c
+++ b/arch/x86/kernel/ptrace_32.c
@@ -104,6 +104,15 @@ static int putreg(struct task_struct *child,
break;
case EFL:
value &= FLAG_MASK;
+ /*
+ * If the user value contains TF, mark that
+ * it was not "us" (the debugger) that set it.
+ * If not, make sure it stays set if we had.
+ */
+ if (value & X86_EFLAGS_TF)
+ clear_tsk_thread_flag(child, TIF_FORCED_TF);
+ else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
+ value |= X86_EFLAGS_TF;
value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK;
break;
}
@@ -119,6 +128,14 @@ static unsigned long getreg(struct task_struct *child,
unsigned long retval = ~0UL;
switch (regno >> 2) {
+ case EFL:
+ /*
+ * If the debugger set TF, hide it from the readout.
+ */
+ retval = get_stack_long(child, EFL_OFFSET);
+ if (test_tsk_thread_flag(child, TIF_FORCED_TF))
+ retval &= ~X86_EFLAGS_TF;
+ break;
case GS:
retval = child->thread.gs;
break;
diff --git a/arch/x86/kernel/ptrace_64.c b/arch/x86/kernel/ptrace_64.c
index 4abfbced9b2..035d53e99c5 100644
--- a/arch/x86/kernel/ptrace_64.c
+++ b/arch/x86/kernel/ptrace_64.c
@@ -143,6 +143,15 @@ static int putreg(struct task_struct *child,
return 0;
case offsetof(struct user_regs_struct, eflags):
value &= FLAG_MASK;
+ /*
+ * If the user value contains TF, mark that
+ * it was not "us" (the debugger) that set it.
+ * If not, make sure it stays set if we had.
+ */
+ if (value & X86_EFLAGS_TF)
+ clear_tsk_thread_flag(child, TIF_FORCED_TF);
+ else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
+ value |= X86_EFLAGS_TF;
tmp = get_stack_long(child, EFL_OFFSET);
tmp &= ~FLAG_MASK;
value |= tmp;
@@ -189,6 +198,17 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno)
if (child->thread.gsindex != GS_TLS_SEL)
return 0;
return get_desc_base(&child->thread.tls_array[GS_TLS]);
+ case offsetof(struct user_regs_struct, eflags):
+ /*
+ * If the debugger set TF, hide it from the readout.
+ */
+ regno = regno - sizeof(struct pt_regs);
+ val = get_stack_long(child, regno);
+ if (test_tsk_thread_flag(child, TIF_IA32))
+ val &= 0xffffffff;
+ if (test_tsk_thread_flag(child, TIF_FORCED_TF))
+ val &= ~X86_EFLAGS_TF;
+ return val;
default:
regno = regno - sizeof(struct pt_regs);
val = get_stack_long(child, regno);
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 1ac53e9a085..0a7c812212c 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -545,14 +545,12 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
}
/*
- * If TF is set due to a debugger (PT_DTRACE), clear the TF flag so
- * that register information in the sigcontext is correct.
+ * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
+ * flag so that register information in the sigcontext is correct.
*/
- if (unlikely(regs->eflags & TF_MASK)
- && likely(current->ptrace & PT_DTRACE)) {
- current->ptrace &= ~PT_DTRACE;
- regs->eflags &= ~TF_MASK;
- }
+ if (unlikely(regs->eflags & X86_EFLAGS_TF) &&
+ likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
+ regs->eflags &= ~X86_EFLAGS_TF;
/* Set up the stack frame */
if (ka->sa.sa_flags & SA_SIGINFO)
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index 38d806467c0..ab0178ebe00 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -349,16 +349,12 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
}
/*
- * If TF is set due to a debugger (PT_DTRACE), clear the TF
- * flag so that register information in the sigcontext is
- * correct.
+ * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
+ * flag so that register information in the sigcontext is correct.
*/
- if (unlikely(regs->eflags & TF_MASK)) {
- if (likely(current->ptrace & PT_DTRACE)) {
- current->ptrace &= ~PT_DTRACE;
- regs->eflags &= ~TF_MASK;
- }
- }
+ if (unlikely(regs->eflags & X86_EFLAGS_TF) &&
+ likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
+ regs->eflags &= ~X86_EFLAGS_TF;
#ifdef CONFIG_IA32_EMULATION
if (test_thread_flag(TIF_IA32)) {
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 6732272e347..243bff650ca 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -135,7 +135,7 @@ void user_enable_single_step(struct task_struct *child)
if (is_setting_trap_flag(child, regs))
return;
- child->ptrace |= PT_DTRACE;
+ set_tsk_thread_flag(child, TIF_FORCED_TF);
}
void user_disable_single_step(struct task_struct *child)
@@ -144,9 +144,6 @@ void user_disable_single_step(struct task_struct *child)
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
/* But touch TF only if it was set by us.. */
- if (child->ptrace & PT_DTRACE) {
- struct pt_regs *regs = task_pt_regs(child);
- regs->eflags &= ~X86_EFLAGS_TF;
- child->ptrace &= ~PT_DTRACE;
- }
+ if (test_and_clear_tsk_thread_flag(child, TIF_FORCED_TF))
+ task_pt_regs(child)->eflags &= ~X86_EFLAGS_TF;
}
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index aa248d75453..874aca397b0 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -865,27 +865,14 @@ asmlinkage void __kprobes do_debug(struct pt_regs * regs,
tsk->thread.debugreg6 = condition;
- /* Mask out spurious TF errors due to lazy TF clearing */
+
+ /*
+ * Single-stepping through TF: make sure we ignore any events in
+ * kernel space (but re-enable TF when returning to user mode).
+ */
if (condition & DR_STEP) {
- /*
- * The TF error should be masked out only if the current
- * process is not traced and if the TRAP flag has been set
- * previously by a tracing process (condition detected by
- * the PT_DTRACE flag); remember that the i386 TRAP flag
- * can be modified by the process itself in user mode,
- * allowing programs to debug themselves without the ptrace()
- * interface.
- */
if (!user_mode(regs))
goto clear_TF_reenable;
- /*
- * Was the TF flag set by a debugger? If so, clear it now,
- * so that register information is correct.
- */
- if (tsk->ptrace & PT_DTRACE) {
- regs->eflags &= ~TF_MASK;
- tsk->ptrace &= ~PT_DTRACE;
- }
}
/* Ok, finally something we can handle */
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 23:27:45 +0000