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https://issues.apache.org/jira/browse/STDCXX-931?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Martin Sebor reassigned STDCXX-931:
-----------------------------------
Assignee: Eric Lemings
Assigned to reporter.
> [gcc/Darwin] 0.printf test aborts with bus error
> ------------------------------------------------
>
> Key: STDCXX-931
> URL: https://issues.apache.org/jira/browse/STDCXX-931
> Project: C++ Standard Library
> Issue Type: Bug
> Components: Test Driver
> Affects Versions: 4.2.1
> Environment: Darwin host.local 9.2.2 Darwin Kernel Version 9.2.2: Tue
> Mar 4 21:17:34 PST 2008; root:xnu-1228.4.31~1/RELEASE_I386 i386
> Reporter: Eric Lemings
> Assignee: Eric Lemings
> Fix For: 4.2.2
>
> Original Estimate: 4h
> Remaining Estimate: 4h
>
> The {{test_string()}} function in the {{0.printf}} test calls
> {{bad_address()}} to generate an invalid address. This address is eventually
> passed to the {{\_\_rw::\_\_rw_memattr()}} function which uses the pointer
> value, specifically {{0x20}}, as the pointer value to the {{memchr()}} C
> library function which promptly aborts the program. The invalid pointer
> should be caught before calling such C library functions which usually expect
> valid pointers. Suspect the proliferous conditional code within the function
> or some other unaccounted platform dependency. The preprocessed Darwin
> source for {{__rw_memattr()}} is shown below.
> {noformat}
> # 97 "/stdcxx/branches/4.2.x/src/memattr.cpp"
> namespace __rw {
> long
> __rw_memattr (const void *addr, unsigned long nbytes, int attr)
> {
> ((void)&attr);
> const int errno_save = (*__error());
> static const unsigned long pgsz = size_t (sysconf (29));
> caddr_t const page =
> reinterpret_cast< caddr_t >(reinterpret_cast< unsigned long >(addr) &
> ~(pgsz - 1))
> ;
> unsigned long npages = nbytes ? nbytes / pgsz + 1 : 0;
> for (size_t i = 0; i < npages; ++i) {
> const caddr_t next = reinterpret_cast< char* >(page) + i * pgsz;
> # 177 "/stdcxx/branches/4.2.x/src/memattr.cpp"
> const int advice = 3;
> if (-1 == madvise (next, 1, advice)) {
> const int err = (*__error());
> (*__error()) = errno_save;
> bool bad_address;
> # 198 "/stdcxx/branches/4.2.x/src/memattr.cpp"
> bad_address = !(0 == err || 22 == err);
> if (bad_address)
> return next == page ? -1 : ( reinterpret_cast< const char*
> >(next) - reinterpret_cast< const char* >(addr));
> }
> if (0xffffffffUL == nbytes) {
> # 219 "/stdcxx/branches/4.2.x/src/memattr.cpp"
> const unsigned long maxpage =
> next == page ? pgsz - ( reinterpret_cast< const char* >(addr)
> - reinterpret_cast< const char* >(next)) : pgsz;
> const void* const pnul =
> memchr (next == page ? addr : next, '\0', maxpage);
> if (pnul) {
> nbytes = ( reinterpret_cast< const char* >(pnul) -
> reinterpret_cast< const char* >(addr));
> npages = nbytes / pgsz + 1;
> break;
> }
> }
> }
> return static_cast< long >(nbytes);
> # 262 "/stdcxx/branches/4.2.x/src/memattr.cpp"
> {noformat}
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