* [LTP] [PATCH 0/1] Test brk vma code path @ 2021-02-09 14:37 Liam Howlett 2021-02-09 14:37 ` [LTP] [PATCH 1/1] brk02: Add test for removing more than one VMA Liam Howlett 0 siblings, 1 reply; 5+ messages in thread From: Liam Howlett @ 2021-02-09 14:37 UTC (permalink / raw) To: ltp The brk system call uses a slightly different code path through the kernel to expand/contract across VMAs. This new test is written to force the VMA to create a two new entries and shrink back across VMA boundaries. Liam R. Howlett (1): brk02: Add test for removing more than one VMA testcases/kernel/syscalls/brk/brk02.c | 49 +++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 testcases/kernel/syscalls/brk/brk02.c -- 2.28.0 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [LTP] [PATCH 1/1] brk02: Add test for removing more than one VMA 2021-02-09 14:37 [LTP] [PATCH 0/1] Test brk vma code path Liam Howlett @ 2021-02-09 14:37 ` Liam Howlett 2021-02-12 10:27 ` Petr Vorel 0 siblings, 1 reply; 5+ messages in thread From: Liam Howlett @ 2021-02-09 14:37 UTC (permalink / raw) To: ltp When brk expands, it attempts to expand a VMA. This expansion will succeed depending on the anonymous VMA chain and if the vma flags are compatible. This test expands brk() then calls mprotect to ensure the next brk call will create a new VMA, then it calls brk a final time to restore the first brk address. The test is the final brk call which will remove more than an entire VMA from the vm area. Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> --- testcases/kernel/syscalls/brk/brk02.c | 49 +++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 testcases/kernel/syscalls/brk/brk02.c diff --git a/testcases/kernel/syscalls/brk/brk02.c b/testcases/kernel/syscalls/brk/brk02.c new file mode 100644 index 000000000..834fe9f2f --- /dev/null +++ b/testcases/kernel/syscalls/brk/brk02.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2021 Liam R. Howlett <liam.howlett@oracle.com> + * + * + * Expand the brk by 2 pages to ensure there is a newly created VMA and not + * expanding the original due to multiple anon pages. mprotect that new VMA + * then brk back to the original address therefore causing a munmap of at + * least one full VMA. + */ + +#include <unistd.h> +#include <stdint.h> +#include <sys/mman.h> + +#include "tst_test.h" + +void brk_down_vmas(void) +{ + void *brk_addr = sbrk(0); + unsigned long page_size = getpagesize(); + void *addr = brk_addr + page_size; + + if (brk(addr)) + return; + + addr += page_size; + if (brk(addr)) + return; + + if (mprotect(addr - page_size, page_size, + PROT_READ|PROT_WRITE|PROT_EXEC)) + return; + + addr += page_size; + if (brk(addr)) + return; + + if (brk(brk_addr)) + return; + + + + tst_res(TPASS, "munmap two VMAs of brk() passed."); +} + +static struct tst_test test = { + .test_all = brk_down_vmas, +}; -- 2.28.0 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [LTP] [PATCH 1/1] brk02: Add test for removing more than one VMA 2021-02-09 14:37 ` [LTP] [PATCH 1/1] brk02: Add test for removing more than one VMA Liam Howlett @ 2021-02-12 10:27 ` Petr Vorel 2021-02-24 21:35 ` Liam Howlett 0 siblings, 1 reply; 5+ messages in thread From: Petr Vorel @ 2021-02-12 10:27 UTC (permalink / raw) To: ltp Hi Liam, thanks for your patch. Minor notes below. > When brk expands, it attempts to expand a VMA. This expansion will > succeed depending on the anonymous VMA chain and if the vma flags are > compatible. This test expands brk() then calls mprotect to ensure the > next brk call will create a new VMA, then it calls brk a final time to > restore the first brk address. The test is the final brk call which > will remove more than an entire VMA from the vm area. > Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> > --- > testcases/kernel/syscalls/brk/brk02.c | 49 +++++++++++++++++++++++++++ > 1 file changed, 49 insertions(+) > create mode 100644 testcases/kernel/syscalls/brk/brk02.c > diff --git a/testcases/kernel/syscalls/brk/brk02.c b/testcases/kernel/syscalls/brk/brk02.c > new file mode 100644 > index 000000000..834fe9f2f > --- /dev/null > +++ b/testcases/kernel/syscalls/brk/brk02.c > @@ -0,0 +1,49 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (c) 2021 Liam R. Howlett <liam.howlett@oracle.com> > + * > + * nit: blank line > + * Expand the brk by 2 pages to ensure there is a newly created VMA and not > + * expanding the original due to multiple anon pages. mprotect that new VMA > + * then brk back to the original address therefore causing a munmap of at > + * least one full VMA. > + */ > + > +#include <unistd.h> > +#include <stdint.h> nit: Not sure if <stdint.h> is needed. > +#include <sys/mman.h> > + > +#include "tst_test.h" > + > +void brk_down_vmas(void) > +{ > + void *brk_addr = sbrk(0); > + unsigned long page_size = getpagesize(); > + void *addr = brk_addr + page_size; > + > + if (brk(addr)) > + return; > + > + addr += page_size; > + if (brk(addr)) > + return; You need to add tst_ret(TFAIL, "failed due ..."); before each return otherwise you get error: tst_test.c:1080: TBROK: Test haven't reported results! > + > + if (mprotect(addr - page_size, page_size, > + PROT_READ|PROT_WRITE|PROT_EXEC)) > + return; > + > + addr += page_size; > + if (brk(addr)) > + return; > + > + if (brk(brk_addr)) > + return; > + > + > + Please remove these blank lines. > + tst_res(TPASS, "munmap two VMAs of brk() passed."); > +} > + > +static struct tst_test test = { > + .test_all = brk_down_vmas, > +}; Kind regards, Petr ^ permalink raw reply [flat|nested] 5+ messages in thread
* [LTP] [PATCH 1/1] brk02: Add test for removing more than one VMA 2021-02-12 10:27 ` Petr Vorel @ 2021-02-24 21:35 ` Liam Howlett 2021-02-25 8:00 ` Petr Vorel 0 siblings, 1 reply; 5+ messages in thread From: Liam Howlett @ 2021-02-24 21:35 UTC (permalink / raw) To: ltp Petr, Thank you for looking at this patch. * Petr Vorel <pvorel@suse.cz> [210212 05:27]: > Hi Liam, > > thanks for your patch. Minor notes below. > > > When brk expands, it attempts to expand a VMA. This expansion will > > succeed depending on the anonymous VMA chain and if the vma flags are > > compatible. This test expands brk() then calls mprotect to ensure the > > next brk call will create a new VMA, then it calls brk a final time to > > restore the first brk address. The test is the final brk call which > > will remove more than an entire VMA from the vm area. > > > Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> > > --- > > testcases/kernel/syscalls/brk/brk02.c | 49 +++++++++++++++++++++++++++ > > 1 file changed, 49 insertions(+) > > create mode 100644 testcases/kernel/syscalls/brk/brk02.c > > > diff --git a/testcases/kernel/syscalls/brk/brk02.c b/testcases/kernel/syscalls/brk/brk02.c > > new file mode 100644 > > index 000000000..834fe9f2f > > --- /dev/null > > +++ b/testcases/kernel/syscalls/brk/brk02.c > > @@ -0,0 +1,49 @@ > > +// SPDX-License-Identifier: GPL-2.0-or-later > > +/* > > + * Copyright (c) 2021 Liam R. Howlett <liam.howlett@oracle.com> > > + * > > + * > nit: blank line Will do. > > + * Expand the brk by 2 pages to ensure there is a newly created VMA and not > > + * expanding the original due to multiple anon pages. mprotect that new VMA > > + * then brk back to the original address therefore causing a munmap of at > > + * least one full VMA. > > + */ > > + > > +#include <unistd.h> > > +#include <stdint.h> > nit: Not sure if <stdint.h> is needed. It is not, thank you. I will fix it. > > > +#include <sys/mman.h> > > + > > +#include "tst_test.h" > > + > > +void brk_down_vmas(void) > > +{ > > + void *brk_addr = sbrk(0); > > + unsigned long page_size = getpagesize(); > > + void *addr = brk_addr + page_size; > > + > > + if (brk(addr)) > > + return; > > + > > + addr += page_size; > > + if (brk(addr)) > > + return; > You need to add tst_ret(TFAIL, "failed due ..."); before each return otherwise > you get error: > tst_test.c:1080: TBROK: Test haven't reported results! I believe you mean tst_res(). I will fix it. > > > + > > + if (mprotect(addr - page_size, page_size, > > + PROT_READ|PROT_WRITE|PROT_EXEC)) > > + return; > > + > > + addr += page_size; > > + if (brk(addr)) > > + return; > > + > > + if (brk(brk_addr)) > > + return; > > + > > + > > + > Please remove these blank lines. Will do. Thank you, Liam > > + tst_res(TPASS, "munmap two VMAs of brk() passed."); > > +} > > + > > +static struct tst_test test = { > > + .test_all = brk_down_vmas, > > +}; > > Kind regards, > Petr ^ permalink raw reply [flat|nested] 5+ messages in thread
* [LTP] [PATCH 1/1] brk02: Add test for removing more than one VMA 2021-02-24 21:35 ` Liam Howlett @ 2021-02-25 8:00 ` Petr Vorel 0 siblings, 0 replies; 5+ messages in thread From: Petr Vorel @ 2021-02-25 8:00 UTC (permalink / raw) To: ltp Hi Liam, > > > + addr += page_size; > > > + if (brk(addr)) > > > + return; > > You need to add tst_ret(TFAIL, "failed due ..."); before each return otherwise > > you get error: > > tst_test.c:1080: TBROK: Test haven't reported results! > I believe you mean tst_res(). I will fix it. Yes, sorry for typo. Thanks for your work! Kind regards, Petr ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-02-25 8:00 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-02-09 14:37 [LTP] [PATCH 0/1] Test brk vma code path Liam Howlett 2021-02-09 14:37 ` [LTP] [PATCH 1/1] brk02: Add test for removing more than one VMA Liam Howlett 2021-02-12 10:27 ` Petr Vorel 2021-02-24 21:35 ` Liam Howlett 2021-02-25 8:00 ` Petr Vorel
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