[ccan] [PATCH] altstack: New module

[Rusty Russell]

Dan Good <dan at dancancode.com> writes:
> altstack - run a function with a dedicated stack, and then release the memory
>
> Signed-off-by: Dan Good <dan at dancancode.com>

Hmm, fails here:
	Linux rusty-Lemur 4.2.0-23-generic #28-Ubuntu SMP Sun Dec 27 17:47:31 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

rusty at rusty-Lemur:~/devel/cvs/ccan/ccan/altstack (master)$ ccanlint -v
Module's run and api tests pass (tests_pass): FAIL
/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:1..16
ok 1 - (fail = getrlimit_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(getrlimit_))) && call1 == (0) && call2 == (0)
ok 2 - (fail = setrlimit_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(setrlimit_))) && call1 == (getrlimit_) && call2 == (0)
ok 3 - (fail = mmap_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(mmap_))) && call1 == (getrlimit_|setrlimit_) && call2 == (setrlimit_)
ok 4 - (fail = sigaltstack_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(sigaltstack_))) && call1 == (getrlimit_|setrlimit_|mmap_) && call2 == (setrlimit_|munmap_)
ok 5 - (fail = sigaction_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(sigaction_))) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_) && call2 == (setrlimit_|munmap_|sigaltstack_)
ok 6 - (fail = munmap_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == 1) && errno == ((900+(munmap_))) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_|sigaction_) && call2 == (setrlimit_|sigaltstack_|sigaction_)
not ok 7 - (altstack(1*((1024UL)*(1024UL)), wrap, (void *) 1000000, 0) == -1) && errno == (75) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_|sigaction_) && call2 == (setrlimit_|munmap_|sigaltstack_|sigaction_)
#     Failed test (/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:main() at line 94)
not ok 8 - (altstack(1*((1024UL)*(1024UL)), wrap, (void *) 1000000, 0) == -1) && errno == (75) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_|sigaction_) && call2 == (setrlimit_|munmap_|sigaltstack_|sigaction_)
#     Failed test (/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:main() at line 99)
not ok 9 - (fail = munmap_) && (altstack(1*((1024UL)*(1024UL)), wrap, (void *) 1000000, 0) == -1) && errno == (75) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_|sigaction_) && call2 == (setrlimit_|sigaltstack_|sigaction_)
#     Failed test (/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:main() at line 104)
not ok 10 - used > 1*MiB-1*KiB && used < 1*MiB
#     Failed test (/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:main() at line 108)
not ok 11 - strcmp(altstack_geterr(), estr) == 0
#     Failed test (/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:main() at line 116)
not ok 12 - strcmp(buf, estr "\n") == 0
#     Failed test (/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:main() at line 124)
not ok 13 - (altstack(8*((1024UL)*(1024UL)), wrap, (void *) 1000000, 0) == -1) && errno == (75) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_|sigaction_) && call2 == (setrlimit_|munmap_|sigaltstack_|sigaction_)
#     Failed test (/home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:main() at line 129)
ok 14 - used > 8*MiB-8*KiB && used < 8*MiB
ok 15 - (altstack(8*((1024UL)*(1024UL)), wrap, (void *) 100000, 0) == 0) && errno == (0) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_|sigaction_|munmap_) && call2 == (setrlimit_|munmap_|sigaltstack_|sigaction_)
ok 16 - used == 32
# Looks like you failed 7 tests of 16.

Should I run the first failing test under the debugger? y    
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Reading symbols from /tmp/ccanlint-12859.1804289383/run...done.
Breakpoint 1 at 0x403148: file /home/rusty/devel/cvs/ccan/ccan/tap/tap.c, line 139.
Starting program: /tmp/ccanlint-12859.1804289383/run 
1..16
ok 1 - (fail = getrlimit_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(getrlimit_))) && call1 == (0) && call2 == (0)
ok 2 - (fail = setrlimit_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(setrlimit_))) && call1 == (getrlimit_) && call2 == (0)
ok 3 - (fail = mmap_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(mmap_))) && call1 == (getrlimit_|setrlimit_) && call2 == (setrlimit_)
ok 4 - (fail = sigaltstack_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(sigaltstack_))) && call1 == (getrlimit_|setrlimit_|mmap_) && call2 == (setrlimit_|munmap_)
ok 5 - (fail = sigaction_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == -1) && errno == ((900+(sigaction_))) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_) && call2 == (setrlimit_|munmap_|sigaltstack_)
ok 6 - (fail = munmap_) && (altstack(8*((1024UL)*(1024UL)), wrap, 0, 0) == 1) && errno == ((900+(munmap_))) && call1 == (getrlimit_|setrlimit_|mmap_|sigaltstack_|sigaction_) && call2 == (setrlimit_|sigaltstack_|sigaction_)

Program received signal SIGSEGV, Segmentation fault.
0x00000000004020b8 in dn (i=967233)
    at /home/rusty/devel/cvs/ccan/ccan/altstack/test/run.c:51
51		if (i) dn(--i);
(gdb) p dn
$1 = {void (unsigned long)} 0x402081 <dn>
(gdb) p i
$2 = 967233