Commit 71384f84 authored Dec 09, 2024 by Kevin Brodsky Committed by Andrew Morton Jan 13, 2025

selftests/mm: fix -Warray-bounds warnings in pkey_sighandler_tests

GCC doesn't like dereferencing a pointer set to 0x1 (when building
at -O2):

pkey_sighandler_tests.c:166:9: warning: array subscript 0 is outside array bounds of 'int[0]' [-Warray-bounds=]
  166 |         *(int *) (0x1) = 1;
      |         ^~~~~~~~~~~~~~
cc1: note: source object is likely at address zero

Using NULL instead seems to make it happy.  This should make no difference
in practice (SIGSEGV with SEGV_MAPERR will be the outcome regardless), we
just need to update the expected si_addr.

[kevin.brodsky@arm.com: fix clang dereferencing-null issue]
  Link: https://lkml.kernel.org/r/20241218153615.2267571-1-kevin.brodsky@arm.com
Link: https://lkml.kernel.org/r/20241209095019.1732120-5-kevin.brodsky@arm.com


Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent 5b6b2799

tools/testing/selftests/mm/pkey_sighandler_tests.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -163,7 +163,7 @@ static void thread_segv_with_pkey0_disabled(void ptr)
		__write_pkey_reg(pkey_reg_restrictive_default());

		/* Segfault (with SEGV_MAPERR) */
		(int ) (0x1) = 1;
		(volatile int )NULL = 1;
		return NULL;
		}

		@@ -179,7 +179,6 @@ static void thread_segv_pkuerr_stack(void ptr)
		static void thread_segv_maperr_ptr(void ptr)
		{
		stack_t *stack = ptr;
		int bad = (int )1;
		u64 pkey_reg;

		/*
		@@ -195,7 +194,7 @@ static void thread_segv_maperr_ptr(void ptr)
		__write_pkey_reg(pkey_reg);

		/* Segfault */
		*bad = 1;
		(volatile int )NULL = 1;
		syscall_raw(SYS_exit, 0, 0, 0, 0, 0, 0);
		return NULL;
		}
		@@ -234,7 +233,7 @@ static void test_sigsegv_handler_with_pkey0_disabled(void)

		ksft_test_result(siginfo.si_signo == SIGSEGV &&
		siginfo.si_code == SEGV_MAPERR &&
		siginfo.si_addr == (void *)1,
		siginfo.si_addr == NULL,
		"%s\n", __func__);
		}

		@@ -349,7 +348,7 @@ static void test_sigsegv_handler_with_different_pkey_for_stack(void)

		ksft_test_result(siginfo.si_signo == SIGSEGV &&
		siginfo.si_code == SEGV_MAPERR &&
		siginfo.si_addr == (void *)1,
		siginfo.si_addr == NULL,
		"%s\n", __func__);
		}