Stefan Eßer d106f982a5 qsort.c: prevent undefined behavior ... Mark Milliard has detected a case of undefined behavior with the LLVM UBSAN. The mandoc program called qsort with a==NULL and n==0, which is allowed by the POSIX standard. The qsort() in FreeBSD did not attempt to perform any accesses using the passed pointer for n==0, but it did add an offset to the pointer value, which is undefined behavior in case of a NULL pointer. This operation has no adverse effects on any achitecture supported by FreeBSD, but could be caught in more strict environments. After some discussion in the freebsd-current mail list, it was concluded that the case of a==NULL and n!=0 should still be caught by UBSAN (or cause a program abort due to an illegal access) in order to not hide errors in programs incorrectly invoking qsort(). Only the the case of a==NULL and n==0 should be fixed to not perform the undefined operation on a NULL pointer. This commit makes qsort() exit before reaching the point of potentially undefined behvior for the case n==0, but does not test the value of a, since the result will not depend on whether this pointer is NULL or an actual pointer to an array if n==0. The issue found by Mark Milliard in the whatis command has been reported to the upstream (OpenBSD) and has already been patched there. MFC after: 1 week		2022-01-13 11:09:38 +01:00
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jemalloc
_Exit.c
a64l.3
a64l.c
abort.3
abort.c
abs.3
abs.c
alloca.3
at_quick_exit.3
atexit.3
atexit.c
atexit.h
atof.3
atof.c
atoi.3
atoi.c
atol.3
atol.c
atoll.c
bsearch.3
bsearch.c
bsearch_b.c
cxa_thread_atexit.c
cxa_thread_atexit_impl.c
div.3
div.c
exit.3	_Exit(3): document implementation	2021-08-08 22:39:46 +03:00
exit.c
getenv.3	libc: add clearenv function	2021-11-07 16:20:15 +01:00
getenv.c	libc: add clearenv function	2021-11-07 16:20:15 +01:00
getopt.3
getopt.c
getopt_long.3
getopt_long.c
getsubopt.3
getsubopt.c
hcreate.3
hcreate.c
hcreate_r.c
hdestroy_r.c
heapsort.c
heapsort_b.c
hsearch.h
hsearch_r.c
imaxabs.3
imaxabs.c
imaxdiv.3
imaxdiv.c
insque.3
insque.c
l64a.c
labs.3
labs.c
ldiv.3
ldiv.c
llabs.3
llabs.c
lldiv.3
lldiv.c
lsearch.3
lsearch.c
Makefile.inc	libc: add clearenv function	2021-11-07 16:20:15 +01:00
memory.3
merge.c	Fix null pointer subtraction in mergesort()	2021-08-27 19:46:18 +02:00
mergesort_b.c
ptsname.3
ptsname.c
qsort.3
qsort.c	qsort.c: prevent undefined behavior	2022-01-13 11:09:38 +01:00
qsort_r.c
qsort_s.c
quick_exit.3
quick_exit.c
radixsort.3
radixsort.c
rand.3
rand.c	Fix race between first rand(3) calls with _once().	2021-07-21 11:32:22 -04:00
random.3
random.c
random.h
reallocarray.3
reallocarray.c
reallocf.3
reallocf.c
realpath.3
realpath.c
remque.c
set_constraint_handler_s.3
set_constraint_handler_s.c
strfmon.3
strfmon.c
strtod.3
strtoimax.c
strtol.3
strtol.c
strtold.c
strtoll.c
strtonum.3
strtonum.c
strtoq.c
strtoul.3
strtoul.c
strtoull.c
strtoumax.c
strtouq.c
Symbol.map	libc: add clearenv function	2021-11-07 16:20:15 +01:00
system.3
system.c
tdelete.c
tfind.c
tsearch.3
tsearch.c
tsearch_path.h
twalk.c