4.4-stable patches

added patches:
	arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
	arm64-debug-ensure-debug-handlers-check-triggering-exception-level.patch

diff --git a/queue-4.14/series b/queue-4.14/series
new file mode 100644 (file)
index 0000000..e7069e2
--- /dev/null
+++ b/queue-4.14/series
@@ -0,0 +1 @@
+arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch

diff --git a/queue-4.19/series b/queue-4.19/series
new file mode 100644 (file)
index 0000000..e7069e2
--- /dev/null
+++ b/queue-4.19/series
@@ -0,0 +1 @@
+arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch

diff --git a/queue-4.4/arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch b/queue-4.4/arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
new file mode 100644 (file)
index 0000000..200ed85
--- /dev/null
+++ b/queue-4.4/arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
@@ -0,0 +1,64 @@
+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
+@@ -589,11 +589,12 @@ 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);
+       struct siginfo info;
+       int rv;
+ 
+@@ -604,16 +605,16 @@ asmlinkage int __exception do_debug_exce
+       if (interrupts_enabled(regs))
+               trace_hardirqs_off();
+ 
+-      if (!inf->fn(addr, esr, regs)) {
++      if (!inf->fn(addr_if_watchpoint, esr, regs)) {
+               rv = 1;
+       } else {
+               pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
+-                       inf->name, esr, addr);
++                       inf->name, esr, pc);
+ 
+               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("", regs, &info, 0);
+               rv = 0;
+       }

diff --git a/queue-4.4/arm64-debug-ensure-debug-handlers-check-triggering-exception-level.patch b/queue-4.4/arm64-debug-ensure-debug-handlers-check-triggering-exception-level.patch
new file mode 100644 (file)
index 0000000..632865a
--- /dev/null
+++ b/queue-4.4/arm64-debug-ensure-debug-handlers-check-triggering-exception-level.patch
@@ -0,0 +1,67 @@
+From 6bd288569b50bc89fa5513031086746968f585cb Mon Sep 17 00:00:00 2001
+From: Will Deacon <will.deacon@arm.com>
+Date: Fri, 1 Mar 2019 13:28:01 +0000
+Subject: arm64: debug: Ensure debug handlers check triggering exception level
+
+From: Will Deacon <will.deacon@arm.com>
+
+commit 6bd288569b50bc89fa5513031086746968f585cb upstream.
+
+Debug exception handlers may be called for exceptions generated both by
+user and kernel code. In many cases, this is checked explicitly, but
+in other cases things either happen to work by happy accident or they
+go slightly wrong. For example, executing 'brk #4' from userspace will
+enter the kprobes code and be ignored, but the instruction will be
+retried forever in userspace instead of delivering a SIGTRAP.
+
+Fix this issue in the most stable-friendly fashion by simply adding
+explicit checks of the triggering exception level to all of our debug
+exception handlers.
+
+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/kernel/kgdb.c |   15 ++++++++++++---
+ 1 file changed, 12 insertions(+), 3 deletions(-)
+
+--- a/arch/arm64/kernel/kgdb.c
++++ b/arch/arm64/kernel/kgdb.c
+@@ -215,22 +215,31 @@ int kgdb_arch_handle_exception(int excep
+ 
+ static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr)
+ {
++      if (user_mode(regs))
++              return DBG_HOOK_ERROR;
++
+       kgdb_handle_exception(1, SIGTRAP, 0, regs);
+-      return 0;
++      return DBG_HOOK_HANDLED;
+ }
+ 
+ static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr)
+ {
++      if (user_mode(regs))
++              return DBG_HOOK_ERROR;
++
+       compiled_break = 1;
+       kgdb_handle_exception(1, SIGTRAP, 0, regs);
+ 
+-      return 0;
++      return DBG_HOOK_HANDLED;
+ }
+ 
+ static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr)
+ {
++      if (user_mode(regs))
++              return DBG_HOOK_ERROR;
++
+       kgdb_handle_exception(1, SIGTRAP, 0, regs);
+-      return 0;
++      return DBG_HOOK_HANDLED;
+ }
+ 
+ static struct break_hook kgdb_brkpt_hook = {

diff --git a/queue-4.4/series b/queue-4.4/series
new file mode 100644 (file)
index 0000000..43ec691
--- /dev/null
+++ b/queue-4.4/series
@@ -0,0 +1,2 @@
+arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
+arm64-debug-ensure-debug-handlers-check-triggering-exception-level.patch

diff --git a/queue-4.9/series b/queue-4.9/series
new file mode 100644 (file)
index 0000000..43ec691
--- /dev/null
+++ b/queue-4.9/series
@@ -0,0 +1,2 @@
+arm64-debug-don-t-propagate-unknown-far-into-si_code-for-debug-signals.patch
+arm64-debug-ensure-debug-handlers-check-triggering-exception-level.patch