Merge tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kernel hardening updates from Kees Cook:
 "Most of the collected changes here are fixes across the tree for
  various hardening features (details noted below).

  The most notable new feature here is the addition of the memcpy()
  overflow warning (under CONFIG_FORTIFY_SOURCE), which is the next step
  on the path to killing the common class of "trivially detectable"
  buffer overflow conditions (i.e. on arrays with sizes known at compile
  time) that have resulted in many exploitable vulnerabilities over the
  years (e.g. BleedingTooth).

  This feature is expected to still have some undiscovered false
  positives. It's been in -next for a full development cycle and all the
  reported false positives have been fixed in their respective trees.
  All the known-bad code patterns we could find with Coccinelle are also
  either fixed in their respective trees or in flight.

  The commit message in commit 54d9469bc515 ("fortify: Add run-time WARN
  for cross-field memcpy()") for the feature has extensive details, but
  I'll repeat here that this is a warning _only_, and is not intended to
  actually block overflows (yet). The many patches fixing array sizes
  and struct members have been landing for several years now, and we're
  finally able to turn this on to find any remaining stragglers.

  Summary:

  Various fixes across several hardening areas:

   - loadpin: Fix verity target enforcement (Matthias Kaehlcke).

   - zero-call-used-regs: Add missing clobbers in paravirt (Bill
     Wendling).

   - CFI: clean up sparc function pointer type mismatches (Bart Van
     Assche).

   - Clang: Adjust compiler flag detection for various Clang changes
     (Sami Tolvanen, Kees Cook).

   - fortify: Fix warnings in arch-specific code in sh, ARM, and xen.

  Improvements to existing features:

   - testing: improve overflow KUnit test, introduce fortify KUnit test,
     add more coverage to LKDTM tests (Bart Van Assche, Kees Cook).

   - overflow: Relax overflow type checking for wider utility.

  New features:

   - string: Introduce strtomem() and strtomem_pad() to fill a gap in
     strncpy() replacement needs.

   - um: Enable FORTIFY_SOURCE support.

   - fortify: Enable run-time struct member memcpy() overflow warning"

* tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (27 commits)
  Makefile.extrawarn: Move -Wcast-function-type-strict to W=1
  hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero
  sparc: Unbreak the build
  x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled
  x86/paravirt: clean up typos and grammaros
  fortify: Convert to struct vs member helpers
  fortify: Explicitly check bounds are compile-time constants
  x86/entry: Work around Clang __bdos() bug
  ARM: decompressor: Include .data.rel.ro.local
  fortify: Adjust KUnit test for modular build
  sh: machvec: Use char[] for section boundaries
  kunit/memcpy: Avoid pathological compile-time string size
  lib: Improve the is_signed_type() kunit test
  LoadPin: Require file with verity root digests to have a header
  dm: verity-loadpin: Only trust verity targets with enforcement
  LoadPin: Fix Kconfig doc about format of file with verity digests
  um: Enable FORTIFY_SOURCE
  lkdtm: Update tests for memcpy() run-time warnings
  fortify: Add run-time WARN for cross-field memcpy()
  fortify: Use SIZE_MAX instead of (size_t)-1
  ...

3 files changed, 20 insertions, 14 deletions

diff --git a/arch/sparc/kernel/leon_smp.c b/arch/sparc/kernel/leon_smp.c
index 1eed26d423fb..991e9ad3d3e8 100644
--- a/arch/sparc/kernel/leon_smp.c
+++ b/arch/sparc/kernel/leon_smp.c
@@ -359,7 +359,7 @@ void leonsmp_ipi_interrupt(void)
 }
 
 static struct smp_funcall {
-	smpfunc_t func;
+	void *func;
 	unsigned long arg1;
 	unsigned long arg2;
 	unsigned long arg3;
@@ -372,7 +372,7 @@ static struct smp_funcall {
 static DEFINE_SPINLOCK(cross_call_lock);
 
 /* Cross calls must be serialized, at least currently. */
-static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
+static void leon_cross_call(void *func, cpumask_t mask, unsigned long arg1,
 			    unsigned long arg2, unsigned long arg3,
 			    unsigned long arg4)
 {
@@ -384,7 +384,7 @@ static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 
 		{
 			/* If you make changes here, make sure gcc generates proper code... */
-			register smpfunc_t f asm("i0") = func;
+			register void *f asm("i0") = func;
 			register unsigned long a1 asm("i1") = arg1;
 			register unsigned long a2 asm("i2") = arg2;
 			register unsigned long a3 asm("i3") = arg3;
@@ -444,11 +444,13 @@ static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 /* Running cross calls. */
 void leon_cross_call_irq(void)
 {
+	void (*func)(unsigned long, unsigned long, unsigned long, unsigned long,
+		     unsigned long) = ccall_info.func;
 	int i = smp_processor_id();
 
 	ccall_info.processors_in[i] = 1;
-	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
-			ccall_info.arg4, ccall_info.arg5);
+	func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3, ccall_info.arg4,
+	     ccall_info.arg5);
 	ccall_info.processors_out[i] = 1;
 }
 
diff --git a/arch/sparc/kernel/sun4d_smp.c b/arch/sparc/kernel/sun4d_smp.c
index ff30f03beb7c..9a62a5cf3337 100644
--- a/arch/sparc/kernel/sun4d_smp.c
+++ b/arch/sparc/kernel/sun4d_smp.c
@@ -268,7 +268,7 @@ static void sun4d_ipi_resched(int cpu)
 }
 
 static struct smp_funcall {
-	smpfunc_t func;
+	void *func;
 	unsigned long arg1;
 	unsigned long arg2;
 	unsigned long arg3;
@@ -281,7 +281,7 @@ static struct smp_funcall {
 static DEFINE_SPINLOCK(cross_call_lock);
 
 /* Cross calls must be serialized, at least currently. */
-static void sun4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
+static void sun4d_cross_call(void *func, cpumask_t mask, unsigned long arg1,
 			     unsigned long arg2, unsigned long arg3,
 			     unsigned long arg4)
 {
@@ -296,7 +296,7 @@ static void sun4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 			 * If you make changes here, make sure
 			 * gcc generates proper code...
 			 */
-			register smpfunc_t f asm("i0") = func;
+			register void *f asm("i0") = func;
 			register unsigned long a1 asm("i1") = arg1;
 			register unsigned long a2 asm("i2") = arg2;
 			register unsigned long a3 asm("i3") = arg3;
@@ -353,11 +353,13 @@ static void sun4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 /* Running cross calls. */
 void smp4d_cross_call_irq(void)
 {
+	void (*func)(unsigned long, unsigned long, unsigned long, unsigned long,
+		     unsigned long) = ccall_info.func;
 	int i = hard_smp_processor_id();
 
 	ccall_info.processors_in[i] = 1;
-	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
-			ccall_info.arg4, ccall_info.arg5);
+	func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3, ccall_info.arg4,
+	     ccall_info.arg5);
 	ccall_info.processors_out[i] = 1;
 }
 
diff --git a/arch/sparc/kernel/sun4m_smp.c b/arch/sparc/kernel/sun4m_smp.c
index 228a6527082d..056df034e79e 100644
--- a/arch/sparc/kernel/sun4m_smp.c
+++ b/arch/sparc/kernel/sun4m_smp.c
@@ -157,7 +157,7 @@ static void sun4m_ipi_mask_one(int cpu)
 }
 
 static struct smp_funcall {
-	smpfunc_t func;
+	void *func;
 	unsigned long arg1;
 	unsigned long arg2;
 	unsigned long arg3;
@@ -170,7 +170,7 @@ static struct smp_funcall {
 static DEFINE_SPINLOCK(cross_call_lock);
 
 /* Cross calls must be serialized, at least currently. */
-static void sun4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
+static void sun4m_cross_call(void *func, cpumask_t mask, unsigned long arg1,
 			     unsigned long arg2, unsigned long arg3,
 			     unsigned long arg4)
 {
@@ -230,11 +230,13 @@ static void sun4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 /* Running cross calls. */
 void smp4m_cross_call_irq(void)
 {
+	void (*func)(unsigned long, unsigned long, unsigned long, unsigned long,
+		     unsigned long) = ccall_info.func;
 	int i = smp_processor_id();
 
 	ccall_info.processors_in[i] = 1;
-	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
-			ccall_info.arg4, ccall_info.arg5);
+	func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3, ccall_info.arg4,
+	     ccall_info.arg5);
 	ccall_info.processors_out[i] = 1;
 }