[PATCH v2 29/70] xen/console: CFI hardening

From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Xen-devel <xen-devel@lists.xenproject.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [PATCH v2 29/70] xen/console: CFI hardening
Date: Mon, 14 Feb 2022 12:50:46 +0000	[thread overview]
Message-ID: <20220214125127.17985-30-andrew.cooper3@citrix.com> (raw)
In-Reply-To: <20220214125127.17985-1-andrew.cooper3@citrix.com>

Control Flow Integrity schemes use toolchain and optionally hardware support
to help protect against call/jump/return oriented programming attacks.

Use cf_check to annotate function pointer targets for the toolchain.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
 xen/drivers/char/console.c   |  4 ++--
 xen/drivers/char/ehci-dbgp.c | 24 +++++++++++++-----------
 xen/drivers/char/ns16550.c   | 26 +++++++++++++-------------
 3 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 380765ab02fd..d9d6556c2293 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -552,7 +552,7 @@ static void __serial_rx(char c, struct cpu_user_regs *regs)
 #endif
 }
 
-static void serial_rx(char c, struct cpu_user_regs *regs)
+static void cf_check serial_rx(char c, struct cpu_user_regs *regs)
 {
     static int switch_code_count = 0;
 
@@ -1286,7 +1286,7 @@ void panic(const char *fmt, ...)
  * **************************************************************
  */
 
-static void suspend_steal_fn(const char *str, size_t nr) { }
+static void cf_check suspend_steal_fn(const char *str, size_t nr) { }
 static int suspend_steal_id;
 
 int console_suspend(void)
diff --git a/xen/drivers/char/ehci-dbgp.c b/xen/drivers/char/ehci-dbgp.c
index a6b57fdf2d19..e205c0da6a61 100644
--- a/xen/drivers/char/ehci-dbgp.c
+++ b/xen/drivers/char/ehci-dbgp.c
@@ -1000,13 +1000,15 @@ static int ehci_dbgp_external_startup(struct ehci_dbgp *dbgp)
 
 typedef void (*set_debug_port_t)(struct ehci_dbgp *, unsigned int);
 
-static void default_set_debug_port(struct ehci_dbgp *dbgp, unsigned int port)
+static void cf_check default_set_debug_port(
+    struct ehci_dbgp *dbgp, unsigned int port)
 {
 }
 
 static set_debug_port_t __read_mostly set_debug_port = default_set_debug_port;
 
-static void nvidia_set_debug_port(struct ehci_dbgp *dbgp, unsigned int port)
+static void cf_check nvidia_set_debug_port(
+    struct ehci_dbgp *dbgp, unsigned int port)
 {
     uint32_t dword = pci_conf_read32(PCI_SBDF(0, dbgp->bus, dbgp->slot,
                                               dbgp->func), 0x74);
@@ -1167,7 +1169,7 @@ static inline void _ehci_dbgp_flush(struct ehci_dbgp *dbgp)
     dbgp->out.chunk = 0;
 }
 
-static void ehci_dbgp_flush(struct serial_port *port)
+static void cf_check ehci_dbgp_flush(struct serial_port *port)
 {
     struct ehci_dbgp *dbgp = port->uart;
     s_time_t goal;
@@ -1196,7 +1198,7 @@ static void ehci_dbgp_flush(struct serial_port *port)
        set_timer(&dbgp->timer, goal);
 }
 
-static void ehci_dbgp_putc(struct serial_port *port, char c)
+static void cf_check ehci_dbgp_putc(struct serial_port *port, char c)
 {
     struct ehci_dbgp *dbgp = port->uart;
 
@@ -1209,7 +1211,7 @@ static void ehci_dbgp_putc(struct serial_port *port, char c)
         ehci_dbgp_flush(port);
 }
 
-static int ehci_dbgp_tx_ready(struct serial_port *port)
+static int cf_check ehci_dbgp_tx_ready(struct serial_port *port)
 {
     struct ehci_dbgp *dbgp = port->uart;
 
@@ -1228,7 +1230,7 @@ static int ehci_dbgp_tx_ready(struct serial_port *port)
            (dbgp->state == dbgp_idle) * DBGP_MAX_PACKET;
 }
 
-static int ehci_dbgp_getc(struct serial_port *port, char *pc)
+static int cf_check ehci_dbgp_getc(struct serial_port *port, char *pc)
 {
     struct ehci_dbgp *dbgp = port->uart;
 
@@ -1309,7 +1311,7 @@ static bool_t ehci_dbgp_setup_preirq(struct ehci_dbgp *dbgp)
     return 0;
 }
 
-static void __init ehci_dbgp_init_preirq(struct serial_port *port)
+static void __init cf_check ehci_dbgp_init_preirq(struct serial_port *port)
 {
     struct ehci_dbgp *dbgp = port->uart;
     u32 debug_port, offset;
@@ -1358,7 +1360,7 @@ static void ehci_dbgp_setup_postirq(struct ehci_dbgp *dbgp)
     set_timer(&dbgp->timer, NOW() + MILLISECS(1));
 }
 
-static void __init ehci_dbgp_init_postirq(struct serial_port *port)
+static void __init cf_check ehci_dbgp_init_postirq(struct serial_port *port)
 {
     struct ehci_dbgp *dbgp = port->uart;
 
@@ -1409,12 +1411,12 @@ static int ehci_dbgp_check_release(struct ehci_dbgp *dbgp)
     return 0;
 }
 
-static void __init ehci_dbgp_endboot(struct serial_port *port)
+static void __init cf_check ehci_dbgp_endboot(struct serial_port *port)
 {
     ehci_dbgp_check_release(port->uart);
 }
 
-static void ehci_dbgp_suspend(struct serial_port *port)
+static void cf_check ehci_dbgp_suspend(struct serial_port *port)
 {
     struct ehci_dbgp *dbgp = port->uart;
 
@@ -1431,7 +1433,7 @@ static void ehci_dbgp_suspend(struct serial_port *port)
     dbgp->state = dbgp_unsafe;
 }
 
-static void ehci_dbgp_resume(struct serial_port *port)
+static void cf_check ehci_dbgp_resume(struct serial_port *port)
 {
     struct ehci_dbgp *dbgp = port->uart;
 
diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 990cad39fe85..8df1ee4d5c2c 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -174,7 +174,7 @@ static void handle_dw_usr_busy_quirk(struct ns16550 *uart)
     }
 }
 
-static void ns16550_interrupt(
+static void cf_check ns16550_interrupt(
     int irq, void *dev_id, struct cpu_user_regs *regs)
 {
     struct serial_port *port = dev_id;
@@ -239,7 +239,7 @@ static void cf_check ns16550_poll(void *data)
 #endif
 }
 
-static int ns16550_tx_ready(struct serial_port *port)
+static int cf_check ns16550_tx_ready(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
 
@@ -250,13 +250,13 @@ static int ns16550_tx_ready(struct serial_port *port)
               uart->lsr_mask ) == uart->lsr_mask ) ? uart->fifo_size : 0;
 }
 
-static void ns16550_putc(struct serial_port *port, char c)
+static void cf_check ns16550_putc(struct serial_port *port, char c)
 {
     struct ns16550 *uart = port->uart;
     ns_write_reg(uart, UART_THR, c);
 }
 
-static int ns16550_getc(struct serial_port *port, char *pc)
+static int cf_check ns16550_getc(struct serial_port *port, char *pc)
 {
     struct ns16550 *uart = port->uart;
 
@@ -344,7 +344,7 @@ static void ns16550_setup_preirq(struct ns16550 *uart)
                  UART_FCR_ENABLE | UART_FCR_CLRX | UART_FCR_CLTX | UART_FCR_TRG14);
 }
 
-static void __init ns16550_init_preirq(struct serial_port *port)
+static void __init cf_check ns16550_init_preirq(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
 
@@ -373,7 +373,7 @@ static void __init ns16550_init_preirq(struct serial_port *port)
         uart->fifo_size = 16;
 }
 
-static void __init ns16550_init_irq(struct serial_port *port)
+static void __init cf_check ns16550_init_irq(struct serial_port *port)
 {
 #ifdef NS16550_PCI
     struct ns16550 *uart = port->uart;
@@ -399,7 +399,7 @@ static void ns16550_setup_postirq(struct ns16550 *uart)
         set_timer(&uart->timer, NOW() + MILLISECS(uart->timeout_ms));
 }
 
-static void __init ns16550_init_postirq(struct serial_port *port)
+static void __init cf_check ns16550_init_postirq(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
     int rc, bits;
@@ -491,7 +491,7 @@ static void __init ns16550_init_postirq(struct serial_port *port)
     ns16550_setup_postirq(uart);
 }
 
-static void ns16550_suspend(struct serial_port *port)
+static void cf_check ns16550_suspend(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
 
@@ -543,7 +543,7 @@ static void cf_check ns16550_delayed_resume(void *data)
         _ns16550_resume(port);
 }
 
-static void ns16550_resume(struct serial_port *port)
+static void cf_check ns16550_resume(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
 
@@ -569,7 +569,7 @@ static void ns16550_resume(struct serial_port *port)
         _ns16550_resume(port);
 }
 
-static void __init ns16550_endboot(struct serial_port *port)
+static void __init cf_check ns16550_endboot(struct serial_port *port)
 {
 #ifdef CONFIG_HAS_IOPORTS
     struct ns16550 *uart = port->uart;
@@ -583,13 +583,13 @@ static void __init ns16550_endboot(struct serial_port *port)
 #endif
 }
 
-static int __init ns16550_irq(struct serial_port *port)
+static int __init cf_check ns16550_irq(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
     return ((uart->irq > 0) ? uart->irq : -1);
 }
 
-static void ns16550_start_tx(struct serial_port *port)
+static void cf_check ns16550_start_tx(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
     u8 ier = ns_read_reg(uart, UART_IER);
@@ -599,7 +599,7 @@ static void ns16550_start_tx(struct serial_port *port)
         ns_write_reg(uart, UART_IER, ier | UART_IER_ETHREI);
 }
 
-static void ns16550_stop_tx(struct serial_port *port)
+static void cf_check ns16550_stop_tx(struct serial_port *port)
 {
     struct ns16550 *uart = port->uart;
     u8 ier = ns_read_reg(uart, UART_IER);
-- 
2.11.0


