selftests/seccomp: Avoid redundant register flushes (e4e8e5d2) · Commits · 戴 / test

When none of the registers have changed, don't flush them back. This can happen if the architecture uses a non-register way to change the syscall (e.g. arm64) , and a return value hasn't been written. Signed-off-by:

Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/lkml/20200912110820.597135-11-keescook@chromium.org Acked-by:

Christian Brauner <christian.brauner@ubuntu.com>

tools/testing/selftests/seccomp/seccomp_bpf.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -1859,11 +1859,12 @@ int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
		void change_syscall(struct __test_metadata *_metadata,
		pid_t tracee, int syscall, int result)
		{
		ARCH_REGS regs;
		ARCH_REGS orig, regs;

		EXPECT_EQ(0, ARCH_GETREGS(regs)) {
		return;
		}
		orig = regs;

		SYSCALL_NUM_SET(regs, syscall);

		@@ -1876,6 +1877,7 @@ void change_syscall(struct __test_metadata *_metadata,
		#endif

		/* Flush any register changes made. */
		if (memcmp(&orig, &regs, sizeof(orig)) != 0)
		EXPECT_EQ(0, ARCH_SETREGS(regs));
		}

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