Mercurial > hg > nginx-quic
view src/os/unix/ngx_gcc_atomic_sparc64.h @ 8481:a45b6a206cfc stable-1.20
Resolver: fixed label types handling in ngx_resolver_copy().
Previously, anything with any of the two high bits set were interpreted
as compression pointers. This is incorrect, as RFC 1035 clearly states
that "The 10 and 01 combinations are reserved for future use". Further,
the 01 combination is actually allocated for EDNS extended label type
(see RFC 2671 and RFC 6891), not really used though.
Fix is to reject unrecognized label types rather than misinterpreting
them as compression pointers.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 25 May 2021 15:17:41 +0300 |
parents | 67653855682e |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ /* * "casa [r1] 0x80, r2, r0" and * "casxa [r1] 0x80, r2, r0" do the following: * * if ([r1] == r2) { * swap(r0, [r1]); * } else { * r0 = [r1]; * } * * so "r0 == r2" means that the operation was successful. * * * The "r" means the general register. * The "+r" means the general register used for both input and output. */ #if (NGX_PTR_SIZE == 4) #define NGX_CASA "casa" #else #define NGX_CASA "casxa" #endif static ngx_inline ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old, ngx_atomic_uint_t set) { __asm__ volatile ( NGX_CASA " [%1] 0x80, %2, %0" : "+r" (set) : "r" (lock), "r" (old) : "memory"); return (set == old); } static ngx_inline ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add) { ngx_atomic_uint_t old, res; old = *value; for ( ;; ) { res = old + add; __asm__ volatile ( NGX_CASA " [%1] 0x80, %2, %0" : "+r" (res) : "r" (value), "r" (old) : "memory"); if (res == old) { return res; } old = res; } } #if (NGX_SMP) #define ngx_memory_barrier() \ __asm__ volatile ( \ "membar #LoadLoad | #LoadStore | #StoreStore | #StoreLoad" \ ::: "memory") #else #define ngx_memory_barrier() __asm__ volatile ("" ::: "memory") #endif #define ngx_cpu_pause()