[PATCH 04/11] arm64: entry: move enter_from_user_mode to entry-common.c

Mark Rutland
2020-11-26T12:38:42Z

In later patches we'll want to extend enter_from_user_mode() and add a
corresponding exit_to_user_mode(). As these will be common for all
entries/exits from userspace, it'd be better for these to live in
entry-common.c with the rest of the entry logic.

This patch moves enter_from_user_mode() into entry-common.c. As with
other functions in entry-common.c it is marked as noinstr (which
prevents all instrumentation, tracing, and kprobes) but there are no
other functional changes.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/kernel/entry-common.c | 6 ++++++
arch/arm64/kernel/traps.c | 7 -------
2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 75e99161f79e..9a685e7686fe 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -101,6 +101,12 @@ asmlinkage void noinstr el1_sync_handler(struct pt_regs *regs)
}
}

+asmlinkage void noinstr enter_from_user_mode(void)
+{
+ CT_WARN_ON(ct_state() != CONTEXT_USER);
+ user_exit_irqoff();
+}
+
static void noinstr el0_da(struct pt_regs *regs, unsigned long esr)
{
unsigned long far = read_sysreg(far_el1);
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 8af4e0e85736..580c60afc39a 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -876,13 +876,6 @@ asmlinkage void do_serror(struct pt_regs *regs, unsigned int esr)
nmi_exit();
}

-asmlinkage void enter_from_user_mode(void)
-{
- CT_WARN_ON(ct_state() != CONTEXT_USER);
- user_exit_irqoff();
-}
-NOKPROBE_SYMBOL(enter_from_user_mode);
-
/* GENERIC_BUG traps */

int is_valid_bugaddr(unsigned long addr)