I think it's better to have it rather than not - safeguarding the code against any compiler optimizations is a preferable thing to me.
BTW, did anybody get a chance to see if the patch actually works on different platforms - it still does not work for me on HP-UX :-(.. it dumps core at apr_rmm_malloc(). -Madhu -----Original Message----- From: Joe Orton [mailto:[EMAIL PROTECTED]] Sent: Friday, March 15, 2002 1:14 AM To: [EMAIL PROTECTED] Subject: Re: cvs commit: httpd-2.0/modules/ssl ssl_scache_shmcb.c ssl_util_table.c On Fri, Mar 15, 2002 at 01:46:47AM -0000, [EMAIL PROTECTED] wrote: > /* This is necessary simply so that the size passed to memset() is not a > * compile-time constant, preventing the compiler from optimising it. */ > +#if 0 > +/* XXX: this isn't used, is it needed? */ > static void shmcb_safe_clear(void *ptr, size_t size) > { > memset(ptr, 0, size); > } > +#endif It was needed in mod_ssl 2.8 as in the below patch, since 'idx' wasn't guaranteed to be word-aligned, and some compilers would optimise the memset into instructions which operated on words. If you can guarantee that idx is word-aligned in 2.0 with the new rmm stuff, it probably isn't needed. Index: ssl_scache_shmcb.c =================================================================== RCS file: /home/cvspublic/httpd-2.0/modules/ssl/ssl_scache_shmcb.c,v retrieving revision 1.7 diff -u -r1.7 ssl_scache_shmcb.c --- ssl_scache_shmcb.c 15 Mar 2002 01:46:47 -0000 1.7 +++ ssl_scache_shmcb.c 15 Mar 2002 08:49:02 -0000 @@ -269,13 +269,10 @@ /* This is necessary simply so that the size passed to memset() is not a * compile-time constant, preventing the compiler from optimising it. */ -#if 0 -/* XXX: this isn't used, is it needed? */ static void shmcb_safe_clear(void *ptr, size_t size) { memset(ptr, 0, size); } -#endif /* Underlying functions for session-caching */ static BOOL shmcb_init_memory(server_rec *, void *, unsigned int); @@ -1178,7 +1175,7 @@ "internal error"); return FALSE; } - memset(idx, 0, sizeof(SHMCBIndex)); + shmcb_safe_clear(idx, sizeof(SHMCBIndex)); shmcb_set_safe_time(&(idx->expires), expiry_time); shmcb_set_safe_uint(&(idx->offset), new_offset);
