Mercurial > hg > nginx
view src/os/unix/ngx_gcc_atomic_amd64.h @ 9274:46ecad404a29 default tip
Mail: reset imap tag to empty after authentication attempt.
We need to reset the imap tag to empty after an authentication attempt
completes, otherwise if the next line parsed is incomplete with no tag
(e.g. empty line) then we use the "tag" from the previous buffer which
is now definitely wrong and has been partially overwritten with the most
recently read data (e.g. CRLF).
An example before this patch:
S: * OK IMAP4 ready
C: foobar login a b
S: foobar NO Incorrect username or password.
C:
S:
S: obar BAD invalid command
Then with this patch:
S: * OK IMAP4 ready
C: foobar login a b
S: foobar NO Incorrect username or password.
C:
S: * BAD invalid command
author | Rob Mueller <robm@fastmailteam.com> |
---|---|
date | Wed, 15 May 2024 10:06:00 +0300 |
parents | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #if (NGX_SMP) #define NGX_SMP_LOCK "lock;" #else #define NGX_SMP_LOCK #endif /* * "cmpxchgq r, [m]": * * if (rax == [m]) { * zf = 1; * [m] = r; * } else { * zf = 0; * rax = [m]; * } * * * The "r" is any register, %rax (%r0) - %r16. * The "=a" and "a" are the %rax register. * Although we can return result in any register, we use "a" because it is * used in cmpxchgq anyway. The result is actually in %al but not in $rax, * however as the code is inlined gcc can test %al as well as %rax. * * The "cc" means that flags were changed. */ 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) { u_char res; __asm__ volatile ( NGX_SMP_LOCK " cmpxchgq %3, %1; " " sete %0; " : "=a" (res) : "m" (*lock), "a" (old), "r" (set) : "cc", "memory"); return res; } /* * "xaddq r, [m]": * * temp = [m]; * [m] += r; * r = temp; * * * The "+r" is any register, %rax (%r0) - %r16. * The "cc" means that flags were changed. */ static ngx_inline ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add) { __asm__ volatile ( NGX_SMP_LOCK " xaddq %0, %1; " : "+r" (add) : "m" (*value) : "cc", "memory"); return add; } #define ngx_memory_barrier() __asm__ volatile ("" ::: "memory") #define ngx_cpu_pause() __asm__ ("pause")