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
  ...

4 files changed, 11 insertions, 10 deletions

diff --git a/arch/riscv/include/asm/bug.h b/arch/riscv/include/asm/bug.h
index f653bfc8a83b..07ceee8b1747 100644
--- a/arch/riscv/include/asm/bug.h
+++ b/arch/riscv/include/asm/bug.h
@@ -86,7 +86,7 @@ struct task_struct;
 
 extern void die(struct pt_regs *regs, const char *str);
 extern void do_trap(struct pt_regs *regs, int signo, int code,
-	unsigned long addr, struct task_struct *tsk);
+	unsigned long addr);
 
 #endif /* !__ASSEMBLY__ */
 
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 1fe1b02e44d0..b14d7647d800 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -126,7 +126,7 @@ badframe:
 			task->comm, task_pid_nr(task), __func__,
 			frame, (void *)regs->sepc, (void *)regs->sp);
 	}
-	force_sig(SIGSEGV, task);
+	force_sig(SIGSEGV);
 	return 0;
 }
 
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 6b32190ba73c..424eb72d56b1 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -55,9 +55,10 @@ void die(struct pt_regs *regs, const char *str)
 		do_exit(SIGSEGV);
 }
 
-void do_trap(struct pt_regs *regs, int signo, int code,
-	unsigned long addr, struct task_struct *tsk)
+void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
 {
+	struct task_struct *tsk = current;
+
 	if (show_unhandled_signals && unhandled_signal(tsk, signo)
 	    && printk_ratelimit()) {
 		pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
@@ -67,14 +68,14 @@ void do_trap(struct pt_regs *regs, int signo, int code,
 		show_regs(regs);
 	}
 
-	force_sig_fault(signo, code, (void __user *)addr, tsk);
+	force_sig_fault(signo, code, (void __user *)addr);
 }
 
 static void do_trap_error(struct pt_regs *regs, int signo, int code,
 	unsigned long addr, const char *str)
 {
 	if (user_mode(regs)) {
-		do_trap(regs, signo, code, addr, current);
+		do_trap(regs, signo, code, addr);
 	} else {
 		if (!fixup_exception(regs))
 			die(regs, str);
@@ -140,7 +141,7 @@ asmlinkage void do_trap_break(struct pt_regs *regs)
 	}
 #endif /* CONFIG_GENERIC_BUG */
 
-	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc), current);
+	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc));
 }
 
 #ifdef CONFIG_GENERIC_BUG
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index f960c3f4ce47..96add1427a75 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -169,7 +169,7 @@ bad_area:
 	up_read(&mm->mmap_sem);
 	/* User mode accesses just cause a SIGSEGV */
 	if (user_mode(regs)) {
-		do_trap(regs, SIGSEGV, code, addr, tsk);
+		do_trap(regs, SIGSEGV, code, addr);
 		return;
 	}
 
@@ -205,7 +205,7 @@ do_sigbus:
 	/* Kernel mode? Handle exceptions or die */
 	if (!user_mode(regs))
 		goto no_context;
-	do_trap(regs, SIGBUS, BUS_ADRERR, addr, tsk);
+	do_trap(regs, SIGBUS, BUS_ADRERR, addr);
 	return;
 
 vmalloc_fault:
@@ -219,7 +219,7 @@ vmalloc_fault:
 
 		/* User mode accesses just cause a SIGSEGV */
 		if (user_mode(regs))
-			return do_trap(regs, SIGSEGV, code, addr, tsk);
+			return do_trap(regs, SIGSEGV, code, addr);
 
 		/*
 		 * Synchronize this task's top level page-table