From 7f63c41c6c57371a0931da3940c6620c2301442c Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 2 May 2007 19:27:13 +0200 Subject: [PATCH] [PATCH] i386: PARAVIRT: Remove CONFIG_DEBUG_PARAVIRT 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 Signed-off-by: Andi Kleen Cc: Rusty Russell --- arch/i386/Kconfig.debug | 10 ---------- arch/i386/kernel/alternative.c | 14 +------------- 2 files changed, 1 insertion(+), 23 deletions(-) diff --git a/arch/i386/Kconfig.debug b/arch/i386/Kconfig.debug index 458bc161193..b31c0802e1c 100644 --- 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 diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c index 9b8e85a8ede..915b6c4d9ba 100644 --- a/arch/i386/kernel/alternative.c +++ b/arch/i386/kernel/alternative.c @@ -334,19 +334,7 @@ void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end) used = 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 = 0; i < 3; i++) { - if (p->len - used >= 2 && (p->clobbers & (1 << i))) { - memcpy(p->instr + used, "\xf7\xd0", 2); - p->instr[used+1] |= i; - used += 2; - } - } - } -#endif + /* Pad the rest with nops */ nop_out(p->instr + used, p->len - used); } -- 2.46.0