view auto/cc/acc @ 9309:92e14ce71b72

Configure: adjusted optimization level for Sun C. With "-fast" (and with "-xbuiltin=%all -xO4"), Sun C miscompiles ngx_http_script_add_copy_code(), which is inlined into ngx_http_script_compile(). From the assembly code it looks like the code uses uninitialized register when calculating new p value after memcpy: movq %r15,%rdi call _memcpy leaq (%r15,rbx),%rax movq (%r12),%rbx movb $0x0000000000000000,(%rax) Note that %rax is set to (%r15 + %rbx), but %rbx is only set after it is used. As such, "*p = '\0'" tries to modify an unrelated memory address, leading to a segmentation fault. The issue was seen in tests which use null-terminated complex values: proxy_ssl_certificate_vars.t, uwsgi_ssl_certificate_vars.t, stream_proxy_ssl_certificate_vars.t. Tested with Sun C compilers from Sun Studio 12.3, 12.4, 12.5, and 12.6. Restructuring code, such as splitting ngx_cpymem() with a separate "p += value->len" increment, fixes things, but it is not clear if its the only place where such miscompilation can happen. Fix is to use "-fast -xO3". Since IPO requires "-xO5", it is commented out.
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 07 Aug 2024 03:56:23 +0300
parents 9eefb38f0005
children
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# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


# aCC: HP ANSI C++ B3910B A.03.55.02

# C89 mode

CFLAGS="$CFLAGS -Ae"
CC_TEST_FLAGS="-Ae"

PCRE_OPT="$PCRE_OPT -Ae"
ZLIB_OPT="$ZLIB_OPT -Ae"