Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...

6 files changed, 16 insertions, 15 deletions

diff --git a/arch/arm/include/asm/traps.h b/arch/arm/include/asm/traps.h
index a00288d75ee6..172b08ff3760 100644
--- a/arch/arm/include/asm/traps.h
+++ b/arch/arm/include/asm/traps.h
@@ -30,7 +30,7 @@ static inline int __in_irqentry_text(unsigned long ptr)
 
 extern void __init early_trap_init(void *);
 extern void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame);
-extern void ptrace_break(struct task_struct *tsk, struct pt_regs *regs);
+extern void ptrace_break(struct pt_regs *regs);
 
 extern void *vectors_page;
 
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index afcb4d3b14dc..324352787aea 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -198,15 +198,15 @@ void ptrace_disable(struct task_struct *child)
 /*
  * Handle hitting a breakpoint.
  */
-void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
+void ptrace_break(struct pt_regs *regs)
 {
 	force_sig_fault(SIGTRAP, TRAP_BRKPT,
-			(void __user *)instruction_pointer(regs), tsk);
+			(void __user *)instruction_pointer(regs));
 }
 
 static int break_trap(struct pt_regs *regs, unsigned int instr)
 {
-	ptrace_break(current, regs);
+	ptrace_break(regs);
 	return 0;
 }
 
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 3ca71d679aec..09f6fdd41974 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -247,7 +247,7 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs)
 	return regs->ARM_r0;
 
 badframe:
-	force_sig(SIGSEGV, current);
+	force_sig(SIGSEGV);
 	return 0;
 }
 
@@ -280,7 +280,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 	return regs->ARM_r0;
 
 badframe:
-	force_sig(SIGSEGV, current);
+	force_sig(SIGSEGV);
 	return 0;
 }
 
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index b6d6b1a6f156..c053abd1fb53 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -369,7 +369,7 @@ void arm_notify_die(const char *str, struct pt_regs *regs,
 		current->thread.error_code = err;
 		current->thread.trap_no = trap;
 
-		force_sig_fault(signo, si_code, addr, current);
+		force_sig_fault(signo, si_code, addr);
 	} else {
 		die(str, regs, err);
 	}
@@ -603,7 +603,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
 
 	case NR(breakpoint): /* SWI BREAK_POINT */
 		regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
-		ptrace_break(current, regs);
+		ptrace_break(regs);
 		return regs->ARM_r0;
 
 	/*
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 6067fa4de22b..8cdb78642e93 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -945,7 +945,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 		goto fixup;
 
 	if (ai_usermode & UM_SIGNAL) {
-		force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr, current);
+		force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr);
 	} else {
 		/*
 		 * We're about to disable the alignment trap and return to
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index ec83c8fca62d..0e417233dad7 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -154,10 +154,11 @@ __do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
  * User mode accesses just cause a SIGSEGV
  */
 static void
-__do_user_fault(struct task_struct *tsk, unsigned long addr,
-		unsigned int fsr, unsigned int sig, int code,
-		struct pt_regs *regs)
+__do_user_fault(unsigned long addr, unsigned int fsr, unsigned int sig,
+		int code, struct pt_regs *regs)
 {
+	struct task_struct *tsk = current;
+
 	if (addr > TASK_SIZE)
 		harden_branch_predictor();
 
@@ -181,7 +182,7 @@ __do_user_fault(struct task_struct *tsk, unsigned long addr,
 	tsk->thread.address = addr;
 	tsk->thread.error_code = fsr;
 	tsk->thread.trap_no = 14;
-	force_sig_fault(sig, code, (void __user *)addr, tsk);
+	force_sig_fault(sig, code, (void __user *)addr);
 }
 
 void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
@@ -194,7 +195,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	 * have no context to handle this fault with.
 	 */
 	if (user_mode(regs))
-		__do_user_fault(tsk, addr, fsr, SIGSEGV, SEGV_MAPERR, regs);
+		__do_user_fault(addr, fsr, SIGSEGV, SEGV_MAPERR, regs);
 	else
 		__do_kernel_fault(mm, addr, fsr, regs);
 }
@@ -390,7 +391,7 @@ retry:
 			SEGV_ACCERR : SEGV_MAPERR;
 	}
 
-	__do_user_fault(tsk, addr, fsr, sig, code, regs);
+	__do_user_fault(addr, fsr, sig, code, regs);
 	return 0;
 
 no_context: