From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 3 Apr 2019 13:57:57 +0000 (+0200)
Subject: 4.19-stable patches
X-Git-Tag: v4.9.168~19
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fb02a6e439896105b38e71d8cbd578ea797b4f88;p=thirdparty%2Fkernel%2Fstable-queue.git

4.19-stable patches

added patches:
	arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
---

diff --git a/queue-4.19/arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch b/queue-4.19/arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
new file mode 100644
index 00000000000..d3be80568de
--- /dev/null
+++ b/queue-4.19/arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
@@ -0,0 +1,66 @@
+From b9a4b9d084d978f80eb9210727c81804588b42ff Mon Sep 17 00:00:00 2001
+From: Will Deacon <will.deacon@arm.com>
+Date: Fri, 1 Mar 2019 13:28:00 +0000
+Subject: arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals
+
+From: Will Deacon <will.deacon@arm.com>
+
+commit b9a4b9d084d978f80eb9210727c81804588b42ff upstream.
+
+FAR_EL1 is UNKNOWN for all debug exceptions other than those caused by
+taking a hardware watchpoint. Unfortunately, if a debug handler returns
+a non-zero value, then we will propagate the UNKNOWN FAR value to
+userspace via the si_addr field of the SIGTRAP siginfo_t.
+
+Instead, let's set si_addr to take on the PC of the faulting instruction,
+which we have available in the current pt_regs.
+
+Cc: <stable@vger.kernel.org>
+Reviewed-by: Mark Rutland <mark.rutland@arm.com>
+Signed-off-by: Will Deacon <will.deacon@arm.com>
+Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ arch/arm64/mm/fault.c |    9 +++++----
+ 1 file changed, 5 insertions(+), 4 deletions(-)
+
+--- a/arch/arm64/mm/fault.c
++++ b/arch/arm64/mm/fault.c
+@@ -827,11 +827,12 @@ void __init hook_debug_fault_code(int nr
+ 	debug_fault_info[nr].name	= name;
+ }
+ 
+-asmlinkage int __exception do_debug_exception(unsigned long addr,
++asmlinkage int __exception do_debug_exception(unsigned long addr_if_watchpoint,
+ 					      unsigned int esr,
+ 					      struct pt_regs *regs)
+ {
+ 	const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
++	unsigned long pc = instruction_pointer(regs);
+ 	int rv;
+ 
+ 	/*
+@@ -841,10 +842,10 @@ asmlinkage int __exception do_debug_exce
+ 	if (interrupts_enabled(regs))
+ 		trace_hardirqs_off();
+ 
+-	if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE)
++	if (user_mode(regs) && pc > TASK_SIZE)
+ 		arm64_apply_bp_hardening();
+ 
+-	if (!inf->fn(addr, esr, regs)) {
++	if (!inf->fn(addr_if_watchpoint, esr, regs)) {
+ 		rv = 1;
+ 	} else {
+ 		struct siginfo info;
+@@ -853,7 +854,7 @@ asmlinkage int __exception do_debug_exce
+ 		info.si_signo = inf->sig;
+ 		info.si_errno = 0;
+ 		info.si_code  = inf->code;
+-		info.si_addr  = (void __user *)addr;
++		info.si_addr  = (void __user *)pc;
+ 		arm64_notify_die(inf->name, regs, &info, esr);
+ 		rv = 0;
+ 	}