From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: [patch 02/20] Remove CONFIG_DEBUG_PARAVIRT Date: Wed, 04 Apr 2007 12:11:53 -0700 Message-ID: <20070404191204.813957928@goop.org> References: <20070404191151.009821039@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline; filename=remove-CONFIG_DEBUG_PARAVIRT.patch List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Andi Kleen Cc: virtualization@lists.osdl.org, Andrew Morton , lkml List-Id: virtualization@lists.linuxfoundation.org Remove CONFIG_DEBUG_PARAVIRT. When inlining code, this option attempts to trash registers in the patch-site's "clobber" field, on the grounds that this should find bugs with incorrect clobbers. Unfortunately, the clobber field really means "registers modified by this patch site", which includes return values. Because of this, this option has outlived its usefulness, so remove it. Signed-off-by: Jeremy Fitzhardinge Cc: Rusty Russell --- arch/i386/Kconfig.debug | 10 ---------- arch/i386/kernel/alternative.c | 14 +------------- 2 files changed, 1 insertion(+), 23 deletions(-) =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- a/arch/i386/Kconfig.debug +++ b/arch/i386/Kconfig.debug @@ -85,14 +85,4 @@ config DOUBLEFAULT option saves about 4k and might cause you much additional grey hair. = -config DEBUG_PARAVIRT - bool "Enable some paravirtualization debugging" - default n - depends on PARAVIRT && DEBUG_KERNEL - help - Currently deliberately clobbers regs which are allowed to be - clobbered in inlined paravirt hooks, even in native mode. - If turning this off solves a problem, then DISABLE_INTERRUPTS() or - ENABLE_INTERRUPTS() is lying about what registers can be clobbered. - endmenu =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- a/arch/i386/kernel/alternative.c +++ b/arch/i386/kernel/alternative.c @@ -359,19 +359,7 @@ void apply_paravirt(struct paravirt_patc = used =3D paravirt_ops.patch(p->instrtype, p->clobbers, p->instr, p->len); -#ifdef CONFIG_DEBUG_PARAVIRT - { - int i; - /* Deliberately clobber regs using "not %reg" to find bugs. */ - for (i =3D 0; i < 3; i++) { - if (p->len - used >=3D 2 && (p->clobbers & (1 << i))) { - memcpy(p->instr + used, "\xf7\xd0", 2); - p->instr[used+1] |=3D i; - used +=3D 2; - } - } - } -#endif + /* Pad the rest with nops */ nop_out(p->instr + used, p->len - used); } -- =