| Message ID | 54889AAC.3060404@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On Wed, 10 Dec 2014, Adhemerval Zanella wrote: > The 'resolv/res_send.c' build with _STRING_ARCH_unaligned not defined > may utilize the local resplen uninitialized. This patch sets it to 0. Do you have an actual path through the function that can result in it being used uninitialized, and where a value of 0 is correct? My understanding, as described in <https://sourceware.org/ml/libc-alpha/2014-11/msg00693.html>, was that this is a false positive warning - the variable is never actually used uninitialized, but determining that requires considering the values other variables can have on the paths leading to resplen being used. And since we don't want to add initializations (to installed code as opposed to testcases) that actually require code to be generated simply in order to avoid warnings, that may indicate disabling -Wmaybe-uninitialized around the code that generates the warning.
On 10-12-2014 19:22, Joseph Myers wrote: > On Wed, 10 Dec 2014, Adhemerval Zanella wrote: > >> The 'resolv/res_send.c' build with _STRING_ARCH_unaligned not defined >> may utilize the local resplen uninitialized. This patch sets it to 0. > Do you have an actual path through the function that can result in it > being used uninitialized, and where a value of 0 is correct? I do not, I used as default just to avoid the warning. > > My understanding, as described in > <https://sourceware.org/ml/libc-alpha/2014-11/msg00693.html>, was that > this is a false positive warning - the variable is never actually used > uninitialized, but determining that requires considering the values other > variables can have on the paths leading to resplen being used. And since > we don't want to add initializations (to installed code as opposed to > testcases) that actually require code to be generated simply in order to > avoid warnings, that may indicate disabling -Wmaybe-uninitialized around > the code that generates the warning. > I understand the idea of avoid such warning, I will the compiler directives.
diff --git a/resolv/res_send.c b/resolv/res_send.c index af42b8a..c1e0a85 100644 --- a/resolv/res_send.c +++ b/resolv/res_send.c @@ -668,7 +668,7 @@ send_vc(res_state statp, // int anssiz = *anssizp; HEADER *anhp = (HEADER *) ans; struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns]; - int truncating, connreset, resplen, n; + int truncating, connreset, resplen = 0, n; struct iovec iov[4]; u_short len; u_short len2;