From: Jeremy Fitzhardinge Subject: [PATCH 18 of 36] x86/paravirt: add debugging for missing operations Date: Wed, 25 Jun 2008 00:19:14 -0400 Message-ID: <3cc92aa2d8e419b47549.1214367554@localhost> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ingo Molnar Cc: Mark McLoughlin , xen-devel , Eduardo Habkost , Stephen Tweedie , x86@kernel.org, LKML List-Id: xen-devel@lists.xenproject.org Rather than just jumping to 0 when there's a missing operation, raise a BUG. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/Kconfig | 7 +++++++ include/asm-x86/paravirt.h | 8 ++++++++ 2 files changed, 15 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -433,6 +433,13 @@ the kernel is theoretically slower and slightly larger. endif + +config PARAVIRT_DEBUG + bool "paravirt-ops debugging" + depends on PARAVIRT && DEBUG_KERNEL + help + Enable to debug paravirt_ops internals. Specifically, BUG if + a paravirt_op is missing when it is called. config MEMTEST bool "Memtest" diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h --- a/include/asm-x86/paravirt.h +++ b/include/asm-x86/paravirt.h @@ -460,10 +460,17 @@ #define VEXTRA_CLOBBERS , "rax", "r8", "r9", "r10", "r11" #endif +#ifdef CONFIG_PARAVIRT_DEBUG +#define PVOP_TEST_NULL(op) BUG_ON(op == NULL) +#else +#define PVOP_TEST_NULL(op) ((void)op) +#endif + #define __PVOP_CALL(rettype, op, pre, post, ...) \ ({ \ rettype __ret; \ PVOP_CALL_ARGS; \ + PVOP_TEST_NULL(op); \ /* This is 32-bit specific, but is okay in 64-bit */ \ /* since this condition will never hold */ \ if (sizeof(rettype) > sizeof(unsigned long)) { \ @@ -492,6 +499,7 @@ #define __PVOP_VCALL(op, pre, post, ...) \ ({ \ PVOP_VCALL_ARGS; \ + PVOP_TEST_NULL(op); \ asm volatile(pre \ paravirt_alt(PARAVIRT_CALL) \ post \