From 297b60346df8beafee954a0fd7c2d64f33f3b9bc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 11 May 2024 01:44:05 +0000
Subject: [PATCH] rtl8211F_led_control
---
kernel/arch/arm64/kernel/syscall.c | 65 ++++++++++++++++++++++++--------
1 files changed, 48 insertions(+), 17 deletions(-)
diff --git a/kernel/arch/arm64/kernel/syscall.c b/kernel/arch/arm64/kernel/syscall.c
index f2d2dbb..6f9839d 100644
--- a/kernel/arch/arm64/kernel/syscall.c
+++ b/kernel/arch/arm64/kernel/syscall.c
@@ -50,10 +50,7 @@
ret = do_ni_syscall(regs, scno);
}
- if (is_compat_task())
- ret = lower_32_bits(ret);
-
- regs->regs[0] = ret;
+ syscall_set_return_value(current, regs, 0, ret);
}
static inline bool has_syscall_work(unsigned long flags)
@@ -101,14 +98,55 @@
regs->orig_x0 = regs->regs[0];
regs->syscallno = scno;
+ /*
+ * BTI note:
+ * The architecture does not guarantee that SPSR.BTYPE is zero
+ * on taking an SVC, so we could return to userspace with a
+ * non-zero BTYPE after the syscall.
+ *
+ * This shouldn't matter except when userspace is explicitly
+ * doing something stupid, such as setting PROT_BTI on a page
+ * that lacks conforming BTI/PACIxSP instructions, falling
+ * through from one executable page to another with differing
+ * PROT_BTI, or messing with BTYPE via ptrace: in such cases,
+ * userspace should not be surprised if a SIGILL occurs on
+ * syscall return.
+ *
+ * So, don't touch regs->pstate & PSR_BTYPE_MASK here.
+ * (Similarly for HVC and SMC elsewhere.)
+ */
+
cortex_a76_erratum_1463225_svc_handler();
- user_exit_irqoff();
local_daif_restore(DAIF_PROCCTX);
+ if (flags & _TIF_MTE_ASYNC_FAULT) {
+ /*
+ * Process the asynchronous tag check fault before the actual
+ * syscall. do_notify_resume() will send a signal to userspace
+ * before the syscall is restarted.
+ */
+ syscall_set_return_value(current, regs, -ERESTARTNOINTR, 0);
+ return;
+ }
+
if (has_syscall_work(flags)) {
- /* set default errno for user-issued syscall(-1) */
+ /*
+ * The de-facto standard way to skip a system call using ptrace
+ * is to set the system call to -1 (NO_SYSCALL) and set x0 to a
+ * suitable error code for consumption by userspace. However,
+ * this cannot be distinguished from a user-issued syscall(-1)
+ * and so we must set x0 to -ENOSYS here in case the tracer doesn't
+ * issue the skip and we fall into trace_exit with x0 preserved.
+ *
+ * This is slightly odd because it also means that if a tracer
+ * sets the system call number to -1 but does not initialise x0,
+ * then x0 will be preserved for all system calls apart from a
+ * user-issued syscall(-1). However, requesting a skip and not
+ * setting the return value is unlikely to do anything sensible
+ * anyway.
+ */
if (scno == NO_SYSCALL)
- regs->regs[0] = -ENOSYS;
+ syscall_set_return_value(current, regs, -ENOSYS, 0);
scno = syscall_trace_enter(regs);
if (scno == NO_SYSCALL)
goto trace_exit;
@@ -124,15 +162,8 @@
if (!has_syscall_work(flags) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) {
local_daif_mask();
flags = current_thread_info()->flags;
- if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP)) {
- /*
- * We're off to userspace, where interrupts are
- * always enabled after we restore the flags from
- * the SPSR.
- */
- trace_hardirqs_on();
+ if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP))
return;
- }
local_daif_restore(DAIF_PROCCTX);
}
@@ -157,14 +188,14 @@
sve_user_disable();
}
-asmlinkage void el0_svc_handler(struct pt_regs *regs)
+void do_el0_svc(struct pt_regs *regs)
{
sve_user_discard();
el0_svc_common(regs, regs->regs[8], __NR_syscalls, sys_call_table);
}
#ifdef CONFIG_COMPAT
-asmlinkage void el0_svc_compat_handler(struct pt_regs *regs)
+void do_el0_svc_compat(struct pt_regs *regs)
{
el0_svc_common(regs, regs->regs[7], __NR_compat_syscalls,
compat_sys_call_table);
--
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