[PATCH 1/2] entry: Fix CONFIG_SECCOMP assumption
From: Ingo Molnar
Date: Sat Jul 25 2020 - 05:20:31 EST
The __secure_computing() callback only exists on CONFIG_SECCOMP=y,
and on architectures that have CONFIG_HAVE_ARCH_SECCOMP_FILTER.
Instead of complicating the #ifdef within the generic entry code,
make the generic entry code depend on the availability of a modern
seccomp framework. This was implicit in the generic code due to
x86 being a modern seccomp-filter architecture.
Also move the Kconfig entry to after its HAVE_ARCH_SECCOMP_FILTER
dependency and fix minor whitespace damage while at it.
Fixes: 142781e108b1: ("entry: Provide generic syscall entry functionality")
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/Kconfig | 6 ++++--
kernel/entry/common.c | 2 ++
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 852a527f418f..c2b29cfc4796 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -27,8 +27,6 @@ config HAVE_IMA_KEXEC
config HOTPLUG_SMT
bool
-config GENERIC_ENTRY
- bool
config OPROFILE
tristate "OProfile system profiling"
@@ -654,6 +652,10 @@ config HAVE_IRQ_EXIT_ON_IRQ_STACK
This spares a stack switch and improves cache usage on softirq
processing.
+config GENERIC_ENTRY
+ bool
+ depends on HAVE_ARCH_SECCOMP_FILTER
+
config PGTABLE_LEVELS
int
default 2
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index 495f5c051b03..49ed8b47773a 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -53,12 +53,14 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
return -1L;
}
+#ifdef CONFIG_SECCOMP
/* Do seccomp after ptrace, to catch any tracer changes. */
if (ti_work & _TIF_SECCOMP) {
ret = __secure_computing(NULL);
if (ret == -1L)
return ret;
}
+#endif
if (unlikely(ti_work & _TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, syscall);
--
2.25.1