| Message ID | 20241022114607.2908-1-roger.pau@citrix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | x86/pv: remove unlikely() from BUG_ON() condition in pv_map_ldt_shadow_page() | expand |
On 22/10/2024 12:46 pm, Roger Pau Monne wrote: > BUG_ON() itself already contains an unlikely() wrapping the bug condition. > > No functional change. > > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> likely()/unlikely() annotations are notoriously difficult for humans to reason about, and I think we have many wrong examples in Xen. In some copious free time, I was thinking of borrowing Linux's ftrace mechanism for identifying broken annotations. All it involves is turning if() into a macro...
diff --git a/xen/arch/x86/pv/mm.c b/xen/arch/x86/pv/mm.c index 24f0d2e4ff7d..187f5f6a3e8c 100644 --- a/xen/arch/x86/pv/mm.c +++ b/xen/arch/x86/pv/mm.c @@ -55,7 +55,7 @@ bool pv_map_ldt_shadow_page(unsigned int offset) l1_pgentry_t gl1e, *pl1e; unsigned long linear = curr->arch.pv.ldt_base + offset; - BUG_ON(unlikely(in_irq())); + BUG_ON(in_irq()); /* * Prior limit checking should guarantee this property. NB. This is
BUG_ON() itself already contains an unlikely() wrapping the bug condition. No functional change. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> --- xen/arch/x86/pv/mm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)