[PATCH] xen/console: introduce is_console_printable()

[dmkhn@xxxxxxxxx]

From: Denis Mukhin <dmukhin@xxxxxxxx>

Add is_console_printable() to implement a common check for printable characters
in the UART emulation and guest logging code.

Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>
---
Link to the original patch:
  
https://lore.kernel.org/xen-devel/20250103-vuart-ns8250-v3-v1-1-c5d36b31d66c@xxxxxxxx/
---
---
 xen/arch/arm/vuart.c       | 5 ++---
 xen/arch/x86/hvm/hvm.c     | 5 ++---
 xen/drivers/char/console.c | 3 +--
 xen/include/xen/console.h  | 6 ++++++
 4 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/xen/arch/arm/vuart.c b/xen/arch/arm/vuart.c
index d5ba483f1e..bd2f425214 100644
--- a/xen/arch/arm/vuart.c
+++ b/xen/arch/arm/vuart.c
@@ -24,7 +24,7 @@
 #include <xen/lib.h>
 #include <xen/sched.h>
 #include <xen/errno.h>
-#include <xen/ctype.h>
+#include <xen/console.h>
 #include <xen/serial.h>
 #include <asm/mmio.h>
 #include <xen/perfc.h>
@@ -79,8 +79,7 @@ static void vuart_print_char(struct vcpu *v, char c)
     struct domain *d = v->domain;
     struct vuart *uart = &d->arch.vuart;
 
-    /* Accept only printable characters, newline, and horizontal tab. */
-    if ( !isprint(c) && (c != '\n') && (c != '\t') )
+    if ( !is_console_printable(c) )
         return ;
 
     spin_lock(&uart->lock);
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 39e39ce4ce..219028969a 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -7,7 +7,6 @@
  * Copyright (c) 2008, Citrix Systems, Inc.
  */
 
-#include <xen/ctype.h>
 #include <xen/init.h>
 #include <xen/ioreq.h>
 #include <xen/lib.h>
@@ -30,6 +29,7 @@
 #include <xen/vpci.h>
 #include <xen/nospec.h>
 #include <xen/vm_event.h>
+#include <xen/console.h>
 #include <asm/shadow.h>
 #include <asm/hap.h>
 #include <asm/current.h>
@@ -561,8 +561,7 @@ static int cf_check hvm_print_line(
     if ( dir != IOREQ_WRITE )
         return X86EMUL_UNHANDLEABLE;
 
-    /* Accept only printable characters, newline, and horizontal tab. */
-    if ( !isprint(c) && (c != '\n') && (c != '\t') )
+    if ( !is_console_printable(c) )
         return X86EMUL_OKAY;
 
     spin_lock(&cd->pbuf_lock);
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 7da8c5296f..b4cec77247 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -24,7 +24,6 @@
 #include <xen/shutdown.h>
 #include <xen/video.h>
 #include <xen/kexec.h>
-#include <xen/ctype.h>
 #include <xen/warning.h>
 #include <asm/div64.h>
 #include <xen/hypercall.h> /* for do_console_io */
@@ -674,7 +673,7 @@ static long 
guest_console_write(XEN_GUEST_HANDLE_PARAM(char) buffer,
                 c = *kin++;
                 if ( c == '\n' )
                     break;
-                if ( isprint(c) || c == '\t' )
+                if ( is_console_printable(c) )
                     *kout++ = c;
             } while ( --kcount > 0 );
 
diff --git a/xen/include/xen/console.h b/xen/include/xen/console.h
index 6dfbade3ec..eac6525c30 100644
--- a/xen/include/xen/console.h
+++ b/xen/include/xen/console.h
@@ -8,6 +8,7 @@
 #define __CONSOLE_H__
 
 #include <xen/inttypes.h>
+#include <xen/ctype.h>
 #include <public/xen.h>
 
 struct xen_sysctl_readconsole;
@@ -50,4 +51,9 @@ void console_serial_puts(const char *s, size_t nr);
 
 extern int8_t opt_console_xen;
 
+static inline bool is_console_printable(unsigned char c)
+{
+       return isprint(c) || c == '\n' || c == '\t';
+}
+
 #endif /* __CONSOLE_H__ */
-- 
2.34.1