On Mon, Sep 28, 2020 at 10:04 AM Konstantin Belousov <kostik...@gmail.com> wrote: > > On Sun, Sep 27, 2020 at 10:08:49PM -0600, Alan Somers wrote: > > On Sun, Sep 27, 2020 at 5:15 PM Konstantin Belousov <kostik...@gmail.com> > > wrote: > > > > > On Sun, Sep 27, 2020 at 10:26:41PM +0000, Alan Somers wrote: > > > > Author: asomers > > > > Date: Sun Sep 27 22:26:41 2020 > > > > New Revision: 366207 > > > > URL: https://svnweb.freebsd.org/changeset/base/366207 > > > > > > > > Log: > > > > Misc compiler warning fixes in lib/libc > > > > > > > > Reviewed by: kevans, imp > > > > MFC after: 2 weeks > > > > Differential Revision: https://reviews.freebsd.org/D26534 > > > > > > > > Modified: > > > > head/lib/libc/gen/auxv.c > > > > head/lib/libc/gen/basename_compat.c > > > > head/lib/libc/gen/crypt.c > > > > head/lib/libc/gen/dirname_compat.c > > > > head/lib/libc/gen/fts-compat.c > > > > head/lib/libc/gen/ftw-compat11.c > > > > head/lib/libc/gen/getentropy.c > > > > > > > > Modified: head/lib/libc/gen/auxv.c > > > > > > > ============================================================================== > > > > --- head/lib/libc/gen/auxv.c Sun Sep 27 21:43:19 2020 (r366206) > > > > +++ head/lib/libc/gen/auxv.c Sun Sep 27 22:26:41 2020 (r366207) > > > > @@ -67,7 +67,8 @@ __init_elf_aux_vector(void) > > > > } > > > > > > > > static pthread_once_t aux_once = PTHREAD_ONCE_INIT; > > > > -static int pagesize, osreldate, canary_len, ncpus, pagesizes_len, > > > bsdflags; > > > > +static int pagesize, osreldate, ncpus, bsdflags; > > > > +static size_t canary_len, pagesizes_len; > > > > static int hwcap_present, hwcap2_present; > > > > static char *canary, *pagesizes, *execpath; > > > > static void *ps_strings, *timekeep; > > > > @@ -245,16 +246,21 @@ int > > > > _elf_aux_info(int aux, void *buf, int buflen) > > > > { > > > > int res; > > > > + size_t buflen_; > > > > > > > > __init_elf_aux_vector(); > > > > if (__elf_aux_vector == NULL) > > > > return (ENOSYS); > > > > _once(&aux_once, init_aux); > > > > > > > > + if (buflen < 0) > > > > + return (EINVAL); > > > > + buflen_ = (size_t)buflen; > > > > + > > > > switch (aux) { > > > > case AT_CANARY: > > > > - if (canary != NULL && canary_len >= buflen) { > > > > - memcpy(buf, canary, buflen); > > > > + if (canary != NULL && canary_len >= buflen_) { > > > > + memcpy(buf, canary, buflen_); > > > > memset(canary, 0, canary_len); > > > > canary = NULL; > > > > res = 0; > > > > @@ -267,35 +273,35 @@ _elf_aux_info(int aux, void *buf, int buflen) > > > > else if (buf == NULL) > > > > res = EINVAL; > > > > else { > > > > - if (strlcpy(buf, execpath, buflen) >= buflen) > > > > + if (strlcpy(buf, execpath, buflen_) >= buflen_) > > > > res = EINVAL; > > > > else > > > > res = 0; > > > > } > > > > break; > > > > case AT_HWCAP: > > > > - if (hwcap_present && buflen == sizeof(u_long)) { > > > > + if (hwcap_present && buflen_ == sizeof(u_long)) { > > > > *(u_long *)buf = hwcap; > > > > res = 0; > > > > } else > > > > res = ENOENT; > > > > break; > > > > case AT_HWCAP2: > > > > - if (hwcap2_present && buflen == sizeof(u_long)) { > > > > + if (hwcap2_present && buflen_ == sizeof(u_long)) { > > > > *(u_long *)buf = hwcap2; > > > > res = 0; > > > > } else > > > > res = ENOENT; > > > > break; > > > > case AT_PAGESIZES: > > > > - if (pagesizes != NULL && pagesizes_len >= buflen) { > > > > - memcpy(buf, pagesizes, buflen); > > > > + if (pagesizes != NULL && pagesizes_len >= buflen_) { > > > > + memcpy(buf, pagesizes, buflen_); > > > > res = 0; > > > > } else > > > > res = ENOENT; > > > > break; > > > > case AT_PAGESZ: > > > > - if (buflen == sizeof(int)) { > > > > + if (buflen_ == sizeof(int)) { > > > > if (pagesize != 0) { > > > > *(int *)buf = pagesize; > > > > res = 0; > > > > @@ -305,7 +311,7 @@ _elf_aux_info(int aux, void *buf, int buflen) > > > > res = EINVAL; > > > > break; > > > > case AT_OSRELDATE: > > > > - if (buflen == sizeof(int)) { > > > > + if (buflen_ == sizeof(int)) { > > > > if (osreldate != 0) { > > > > *(int *)buf = osreldate; > > > > res = 0; > > > > @@ -315,7 +321,7 @@ _elf_aux_info(int aux, void *buf, int buflen) > > > > res = EINVAL; > > > > break; > > > > case AT_NCPUS: > > > > - if (buflen == sizeof(int)) { > > > > + if (buflen_ == sizeof(int)) { > > > > if (ncpus != 0) { > > > > *(int *)buf = ncpus; > > > > res = 0; > > > > @@ -325,7 +331,7 @@ _elf_aux_info(int aux, void *buf, int buflen) > > > > res = EINVAL; > > > > break; > > > > case AT_TIMEKEEP: > > > > - if (buflen == sizeof(void *)) { > > > > + if (buflen_ == sizeof(void *)) { > > > > if (timekeep != NULL) { > > > > *(void **)buf = timekeep; > > > > res = 0; > > > > @@ -335,14 +341,14 @@ _elf_aux_info(int aux, void *buf, int buflen) > > > > res = EINVAL; > > > > break; > > > > case AT_BSDFLAGS: > > > > - if (buflen == sizeof(int)) { > > > > + if (buflen_ == sizeof(int)) { > > > > *(int *)buf = bsdflags; > > > > res = 0; > > > > } else > > > > res = EINVAL; > > > > break; > > > > case AT_PS_STRINGS: > > > > - if (buflen == sizeof(void *)) { > > > > + if (buflen_ == sizeof(void *)) { > > > > if (ps_strings != NULL) { > > > > *(void **)buf = ps_strings; > > > > res = 0; > > > > > > This is significant uglification of the code in the name of fixing > > > pointless > > > warnings. > > > > > > > Warnings are NOT pointless. 99% of them are. But the only way to find the > > 1% that aren't is to quell the 99% that are. Last week I wrote a bug that > > fortunately got caught in code review. But it shouldn't have made it that > > far. It should've been caught by the compiler, but libc is only built with > > WARNS=2. This commit is one step towards raising libc's WARNs level to 3. > > Only 334 files left to go. > I specifically replied to the part of the change that I quoted. I did not > discussed generic arguments WRT handling some warnings. > > > > > > > > > > > I suspect that you tried to shut down warning about comparision of > > > integers > > > of different size, int vs. sizeof() which has size_t result. Is there > > > anything else ? > > > > > > > Mostly the warnings were about comparisons of integers with different > > signedness. Also there were some warnings about missing prototypes. > In this fragment ? I think no, so only signess mismatch. > > > > > > > > > > > All these values should be small integers, which is quite vividly > > > illustrated by comparision with sizeof() of built-in types. If compiler > > > cannot deduce that itself the warning should be forcibly disabled by > > > flag instead of doing 'buflen_'. > > > > > > And canary_len/pagesizes_len do not need to take 8 bytes, their values > > > never become greater than one hundred. > > > > > > > Better to give it enough space that the compiler can check it statically, > > rather than require runtime checks. > Natural and proper type for small numerical values in C is int. Both > external interface for the API, and internal implementation are built > around this. Making internal details mismatch the external view on the > interface make it much more risky then leaving warning that is mostly > due to the compiler deficiency. > > Using size_t is not appropriate there. I prefer this warning to be shut > down for the file with the compiler switch. If you are so inclined to > shut it in the source code, please either change the type of unneeded > variable to unsigned int (and also perhaps applying ScottL suggestion), > or just do casts to int in comparisions.
I would be tempted to just revert the rest of the local modifications (sans negative check, maybe) and widen it in the one spot that the compiler complains about: - if (strlcpy(buf, execpath, buflen_) >= buflen_) + if (strlcpy(buf, execpath, buflen) >= (size_t)buflen) I had expressed this in the review, but with no particular conviction. Thanks, Kyle Evans _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
