[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[PATCH 55/65] x86/bugframe: Annotate fnptr targets


  • To: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
  • Date: Fri, 26 Nov 2021 12:34:36 +0000
  • Authentication-results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none
  • Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Jan Beulich <JBeulich@xxxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>
  • Delivery-date: Fri, 26 Nov 2021 13:04:51 +0000
  • Ironport-data: A9a23:xsW1ZqwlI6JOurp/Ay56t+f6wSrEfRIJ4+MujC+fZmUNrF6WrkVUn TYfWW3SPvaCYWf1eo1xPI3j8hkOsJXTn9c3TwVlqyAxQypGp/SeCIXCJC8cHc8zwu4v7q5Dx 59DAjUVBJlsFhcwnvopW1TYhSEUOZugH9IQM8aZfHAuLeNYYH1500s6wrRn2tQAbeWRWGthh /uj+6UzB3f9s9JEGjp8B3Wr8U4HUFza4Vv0j3RmDRx5lAa2e0o9VfrzEZqZPXrgKrS4K8bhL wr1IBNVyUuCl/slIovNfr8W6STmSJaKVeSFoiI+t6RPHnGuD8H9u0o2HKN0VKtZt9mGt8FOz 9pVk5DocgAKfYHsqLQAQQR9IS4raMWq+JefSZS+mcmazkmAeHrw2fR+SkoxOOX0+M4uXzsIr 6ZBbmlQMFbT3Ipaw5riIgVoru0lINPmI8U0vXZ4wCuCJf0nXYrCU+PB4towMDIY25AQQqiFP ptxhTxHdE/Zb01SJ3AsWb0Yuuir2CjmUxRRpwfAzUYwyzeKl1EguFT3C/LKfvSaSMMTmVyXz krk1WnkBhARNPSE1CGItHmrg4fnjS79HY4fCrC83vprm0GIgHweDgUMUlm2quX/jVSxM++zM GRNpHBo9/JrshX2EJ+tBHVUvUJooDYNZN1fC8s2sDqK6en4wzbJG3oZawxOPYlOWNANeRQm0 VqAntXMDDNpsaGIRX/1yop4vQ9eKgBOczZcOHZsoR8tpoC6/dpt1k6nosNLSfbt1rXI9SfML ydmRcTUr5EaloY12qqy5jgraBr898GSHmbZCug6N19JDz+Vhqb5OORECnCBtJ6sybp1qHHa5 xDofODEsYgz4WmlznDlfQn0NOjBCwy5GDPdm0VzOJIq6i6g/XWuFagJvmohdBk0bZdYJ2OyC KM2he+3zMQIVJdNRfUqC79d9uxwlfSwfTgbfqy8giVyjmhZK1bcoXAGib+41GHxikk8+ZzTy r/AGftA+U0yUPw9pBLvHr91+eZymkgWmDOCLbimnk/P+efPOxaopUItbQLmghYRt/jf/m04M r93aqO39vmoeLGkP3SMr9dMdQtiwLpSLcmelvG7v9WremJOcFzNwdeLqV/4U4A6zalTiMnS+ XSxBh1RxFbl3CWVIgSWcHFzLrjoWM8n/348OCUtO3eu2mQiPtnzvPtOKcNvcOl17vFnwN51U +IBJ5eKDMNQR2mV4D8ad5T88tBvLUz5mQKUMiO5SzEjZJo8FRfR89rpc1K3pikDBya6r+Ukp Lik2l+JSJYPXV06Xs3XdOiu3xW6un1EwLB+WE7BI99yfkTw8dc1d3yt36Fve8xVcEfN3DqX0 QqSECw0n+iVrt9n6sTNiICFs5ytT7l0EH1FEjSJ9r2xLyTboDaumNcSTOaScDnBf2ro46H+N /5NxvTxPfBbzlZHt41wT+Riwa4kvoa9orZbykJvHWnRbkTtAbRleyHU0c5Kv6xL57lYpQrpB R7fpogEYe2EaJH/DVocBAs5deDSh/gblw7b4ekxPEintjR8+6CKUBkKMhSB4MCHwGCZ7G/xL T8dhfMr
  • Ironport-hdrordr: A9a23:SCgZ06v0/TEX60kqCvjsIDGn7skDTtV00zEX/kB9WHVpmszxra 6TdZMgpGbJYVcqKRcdcL+7WJVoLUmxyXcx2/h1AV7AZniAhILLFvAA0WKK+VSJcEeSygce79 YFT0EXMqyJMbEQt6fHCWeDfOrIuOP3kpyVuQ==
  • Ironport-sdr: KeRx9sKZ+rVuae8W+b2HPau0rRsDaLoRSPCz/VU2HOfd97UJk91ogFSfaooAmqE/ij+HYfi+iZ +u3e9iMZXz71TR42oHTAKoUGJXnAslglXD574vRVlCDncYckwh0Kvyqff5xqiN/SMnRZLtB90l 2HkkFHAkIJUgTgTGtjtShEzzzS7W80XUfOwITQOtn9Oq2MjtKjrIqu7o7ft1+RnnRw6uOr2kf4 kPPpP9uJMUuBxEi1ssVUGoTJWOpCdlO/iSSeCDIMmco3UpINWRHjfMozGWSYNgLBM0uYBVgAsL Td0YH4GQl1G7MTNjI5T2fcuB
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

run_in_exception_handler() managed to escape typechecking, as the compiler
can't see where function pointer gets called.  After adding some ad-hoc
typechecking, it turns out that dump_execution_state() alone differs in
const-ness from the other users of run_in_exception_handler().

Introduce a new show_execution_state_nonconst() to make the typechecking
happy.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
---
 xen/arch/x86/traps.c            |  5 +++++
 xen/common/keyhandler.c         |  4 ++--
 xen/drivers/char/ehci-dbgp.c    |  2 +-
 xen/drivers/char/ns16550.c      |  2 +-
 xen/include/asm-x86/bug.h       | 10 +++++++++-
 xen/include/asm-x86/processor.h |  4 +++-
 xen/include/xen/lib.h           |  2 +-
 7 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 76b1b779b33c..81ab96115ead 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -670,6 +670,11 @@ void show_execution_state(const struct cpu_user_regs *regs)
     console_unlock_recursive_irqrestore(flags);
 }
 
+void cf_check show_execution_state_nonconst(struct cpu_user_regs *regs)
+{
+    show_execution_state(regs);
+}
+
 void vcpu_show_execution_state(struct vcpu *v)
 {
     unsigned long flags = 0;
diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index 5dc650a37c5c..b6e22d8120b1 100644
--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -138,7 +138,7 @@ static void cf_check show_handlers(unsigned char key)
 
 static cpumask_t dump_execstate_mask;
 
-void dump_execstate(struct cpu_user_regs *regs)
+void cf_check dump_execstate(struct cpu_user_regs *regs)
 {
     unsigned int cpu = smp_processor_id();
 
@@ -490,7 +490,7 @@ static void cf_check run_all_keyhandlers(
     tasklet_schedule(&run_all_keyhandlers_tasklet);
 }
 
-static void do_debugger_trap_fatal(struct cpu_user_regs *regs)
+static void cf_check do_debugger_trap_fatal(struct cpu_user_regs *regs)
 {
     (void)debugger_trap_fatal(0xf001, regs);
 
diff --git a/xen/drivers/char/ehci-dbgp.c b/xen/drivers/char/ehci-dbgp.c
index e205c0da6a61..16c8ff394d5c 100644
--- a/xen/drivers/char/ehci-dbgp.c
+++ b/xen/drivers/char/ehci-dbgp.c
@@ -1247,7 +1247,7 @@ static int cf_check ehci_dbgp_getc(struct serial_port 
*port, char *pc)
 /* Safe: ehci_dbgp_poll() runs as timer handler, so not reentrant. */
 static struct serial_port *poll_port;
 
-static void _ehci_dbgp_poll(struct cpu_user_regs *regs)
+static void cf_check _ehci_dbgp_poll(struct cpu_user_regs *regs)
 {
     struct serial_port *port = poll_port;
     struct ehci_dbgp *dbgp = port->uart;
diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 8df1ee4d5c2c..e5b4a9085516 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -206,7 +206,7 @@ static void cf_check ns16550_interrupt(
 /* Safe: ns16550_poll() runs as softirq so not reentrant on a given CPU. */
 static DEFINE_PER_CPU(struct serial_port *, poll_port);
 
-static void __ns16550_poll(struct cpu_user_regs *regs)
+static void cf_check __ns16550_poll(struct cpu_user_regs *regs)
 {
     struct serial_port *port = this_cpu(poll_port);
     struct ns16550 *uart = port->uart;
diff --git a/xen/include/asm-x86/bug.h b/xen/include/asm-x86/bug.h
index 9bb4a194202f..b7265bdfbe33 100644
--- a/xen/include/asm-x86/bug.h
+++ b/xen/include/asm-x86/bug.h
@@ -65,7 +65,15 @@ struct bug_frame {
     unreachable();                                              \
 } while (0)
 
-#define run_in_exception_handler(fn) BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, NULL)
+/*
+ * TODO: untangle header dependences, break BUILD_BUG_ON() out of xen/lib.h,
+ * and use a real static inline here to get proper type checking of fn().
+ */
+#define run_in_exception_handler(fn)                            \
+    do {                                                        \
+        (void)((fn) == (void (*)(struct cpu_user_regs *))NULL); \
+        BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, NULL);             \
+    } while ( 0 )
 
 #define assert_failed(msg) do {                                 \
     BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg);     \
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index f031a050cba0..547415ec68e1 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -497,7 +497,9 @@ void show_stack(const struct cpu_user_regs *regs);
 void show_stack_overflow(unsigned int cpu, const struct cpu_user_regs *regs);
 void show_registers(const struct cpu_user_regs *regs);
 void show_execution_state(const struct cpu_user_regs *regs);
-#define dump_execution_state() run_in_exception_handler(show_execution_state)
+void cf_check show_execution_state_nonconst(struct cpu_user_regs *regs);
+#define dump_execution_state() \
+    run_in_exception_handler(show_execution_state_nonconst)
 void show_page_walk(unsigned long addr);
 void noreturn fatal_trap(const struct cpu_user_regs *regs, bool_t show_remote);
 
diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index c6987973bf88..3a1fdaf7e35a 100644
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -199,7 +199,7 @@ extern char *print_tainted(char *str);
 extern void add_taint(unsigned int taint);
 
 struct cpu_user_regs;
-void dump_execstate(struct cpu_user_regs *);
+void cf_check dump_execstate(struct cpu_user_regs *);
 
 void init_constructors(void);
 
-- 
2.11.0




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.