This series aims to add support to bpf_snprintf_btf() and
bpf_seq_printf_btf() allowing them to store string representations
of module-specific types, as well as the kernel-specific ones
they currently support.
Patch 1 removes the btf_module_mutex, as since we will need to
look up module BTF during BPF program execution, we don't want
to risk sleeping in the various contexts in which BPF can run.
The access patterns to the btf module list seem to conform to
classic list RCU usage so with a few minor tweaks this seems
workable.
Patch 2 replaces the unused flags field in struct btf_ptr with
an obj_id field, allowing the specification of the id of a
BTF module. If the value is 0, the core kernel vmlinux is
assumed to contain the type's BTF information. Otherwise the
module with that id is used to identify the type. If the
object-id based lookup fails, we again fall back to vmlinux
BTF.
Patch 3 is a selftest that uses veth (when built as a
module) and a kprobe to display both a module-specific
and kernel-specific type; both are arguments to veth_stats_rx().
Currently it looks up the module-specific type and object ids
using libbpf; in future, these lookups will likely be supported
directly in the BPF program via __builtin_btf_type_id(); but
I need to determine a good test to determine if that builtin
supports object ids.
Changes since RFC
- add patch to remove module mutex
- modify to use obj_id instead of module name as identifier
in "struct btf_ptr" (Andrii)
Alan Maguire (3):
bpf: eliminate btf_module_mutex as RCU synchronization can be used
bpf: add module support to btf display helpers
selftests/bpf: verify module-specific types can be shown via
bpf_snprintf_btf
include/linux/btf.h | 12 ++
include/uapi/linux/bpf.h | 13 ++-
kernel/bpf/btf.c | 49 +++++---
kernel/trace/bpf_trace.c | 44 ++++++--
tools/include/uapi/linux/bpf.h | 13 ++-
.../selftests/bpf/prog_tests/snprintf_btf_mod.c | 124 +++++++++++++++++++++
tools/testing/selftests/bpf/progs/bpf_iter.h | 2 +-
tools/testing/selftests/bpf/progs/btf_ptr.h | 2 +-
tools/testing/selftests/bpf/progs/veth_stats_rx.c | 72 ++++++++++++
9 files changed, 292 insertions(+), 39 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/snprintf_btf_mod.c
create mode 100644 tools/testing/selftests/bpf/progs/veth_stats_rx.c
--
1.8.3.1
When compiling the selftests with the -std=gnu99 option the build can
fail with.
Following build error:
test_core.c: In function ‘test_cgcore_destroy’:
test_core.c:87:2: error: ‘for’ loop initial declarations are only
allowed in C99 mode
for (int i = 0; i < 10; i++) {
^
test_core.c:87:2: note: use option -std=c99 or -std=gnu99 to compile
Add -std=gnu99 to the clone3 selftest Makefile to fix this.
Signed-off-by: Xingxing Su <suxingxing(a)loongson.cn>
Acked-by: Christian Brauner <christian.brauner(a)ubuntu.com>
---
tools/testing/selftests/clone3/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
index ef7564c..88354a8 100644
--- a/tools/testing/selftests/clone3/Makefile
+++ b/tools/testing/selftests/clone3/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-CFLAGS += -g -I../../../../usr/include/
+CFLAGS += -g -std=gnu99 -I../../../../usr/include/
LDLIBS += -lcap
TEST_GEN_PROGS := clone3 clone3_clear_sighand clone3_set_tid \
--
1.8.3.1
Except arch x86, the function rseq_offset_deref_addv is not defined.
The function test_membarrier_manager_thread call rseq_offset_deref_addv
produces a build error.
The RSEQ_ARCH_HAS_OFFSET_DEREF_ADD should contain all the code
for the MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ.
If the other Arch implements this feature,
defined RSEQ_ARCH_HAS_OFFSET_DEREF_ADD in the header file
to ensure that this feature is available.
Following build errors:
param_test.c: In function ‘test_membarrier_worker_thread’:
param_test.c:1164:10: warning: implicit declaration of function ‘rseq_offset_deref_addv’
ret = rseq_offset_deref_addv(&args->percpu_list_ptr,
^~~~~~~~~~~~~~~~~~~~~~
/tmp/ccMj9yHJ.o: In function `test_membarrier_worker_thread':
param_test.c:1164: undefined reference to `rseq_offset_deref_addv'
param_test.c:1164: undefined reference to `rseq_offset_deref_addv'
collect2: error: ld returned 1 exit status
make: *** [/selftests/rseq/param_test_benchmark] Error 1
Signed-off-by: Xingxing Su <suxingxing(a)loongson.cn>
---
tools/testing/selftests/rseq/param_test.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 3845890..699ad5f 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -1133,6 +1133,8 @@ static int set_signal_handler(void)
return ret;
}
+/* Test MEMBARRIER_CMD_PRIVATE_RESTART_RSEQ_ON_CPU membarrier command. */
+#ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
struct test_membarrier_thread_args {
int stop;
intptr_t percpu_list_ptr;
@@ -1286,8 +1288,6 @@ void *test_membarrier_manager_thread(void *arg)
return NULL;
}
-/* Test MEMBARRIER_CMD_PRIVATE_RESTART_RSEQ_ON_CPU membarrier command. */
-#ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
void test_membarrier(void)
{
const int num_threads = opt_threads;
--
1.8.3.1
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call
that must be intercepted via SIE, handled in userspace, and the
information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which
simply has a VM execute the instruction and then userspace will extract
the necessary info. The handler is defined such that the instruction
invocation occurs only once. It is up to the caller to determine how the
info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs
call. This is tested during a sync_regs test, where the diag318 info is
requested via the handler, then the info is stored in the appropriate
register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message
stating that diag318 was skipped, and the asserts will simply test
against a value of 0.
Signed-off-by: Collin Walling <walling(a)linux.ibm.com>
---
v3 changes: no longer testing the reset code, as it is handled
entirely via userspace. The respective reset tests have been removed
---
tools/testing/selftests/kvm/Makefile | 2 +-
.../kvm/include/s390x/diag318_test_handler.h | 13 +++
.../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++
tools/testing/selftests/kvm/s390x/resets.c | 1 +
.../selftests/kvm/s390x/sync_regs_test.c | 16 +++-
5 files changed, 112 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h
create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 3d14ef77755e..426c78449044 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -36,7 +36,7 @@ endif
LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c
LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S
LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c
-LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c
+LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
diff --git a/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h
new file mode 100644
index 000000000000..b0ed71302722
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * Test handler for the s390x DIAGNOSE 0x0318 instruction.
+ *
+ * Copyright (C) 2020, IBM
+ */
+
+#ifndef SELFTEST_KVM_DIAG318_TEST_HANDLER
+#define SELFTEST_KVM_DIAG318_TEST_HANDLER
+
+uint64_t get_diag318_info(void);
+
+#endif
diff --git a/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
new file mode 100644
index 000000000000..1e0b766efeb7
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Test handler for the s390x DIAGNOSE 0x0318 instruction.
+ *
+ * Copyright (C) 2020, IBM
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+
+#define VCPU_ID 5
+
+#define ICPT_INSTRUCTION 0x04
+#define IPA0_DIAG 0x8300
+
+static void guest_code(void)
+{
+ uint64_t diag318_info = 0x12345678;
+
+ asm volatile ("diag %0,0,0x318\n" : : "d" (diag318_info));
+}
+
+/*
+ * The DIAGNOSE 0x0318 instruction call must be handled via userspace. As such,
+ * we create an ad-hoc VM here to handle the instruction then extract the
+ * necessary data. It is up to the caller to decide what to do with that data.
+ */
+static uint64_t diag318_handler(void)
+{
+ struct kvm_vm *vm;
+ struct kvm_run *run;
+ uint64_t reg;
+ uint64_t diag318_info;
+
+ vm = vm_create_default(VCPU_ID, 0, guest_code);
+ vcpu_run(vm, VCPU_ID);
+ run = vcpu_state(vm, VCPU_ID);
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
+ "DIAGNOSE 0x0318 instruction was not intercepted");
+ TEST_ASSERT(run->s390_sieic.icptcode == ICPT_INSTRUCTION,
+ "Unexpected intercept code: 0x%x", run->s390_sieic.icptcode);
+ TEST_ASSERT((run->s390_sieic.ipa & 0xff00) == IPA0_DIAG,
+ "Unexpected IPA0 code: 0x%x", (run->s390_sieic.ipa & 0xff00));
+
+ reg = (run->s390_sieic.ipa & 0x00f0) >> 4;
+ diag318_info = run->s.regs.gprs[reg];
+
+ TEST_ASSERT(diag318_info != 0, "DIAGNOSE 0x0318 info not set");
+
+ kvm_vm_free(vm);
+
+ return diag318_info;
+}
+
+uint64_t get_diag318_info(void)
+{
+ static uint64_t diag318_info;
+ static bool printed_skip;
+
+ /*
+ * If KVM does not support diag318, then return 0 to
+ * ensure tests do not break.
+ */
+ if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) {
+ if (!printed_skip) {
+ fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. "
+ "Skipping diag318 test.\n");
+ printed_skip = true;
+ }
+ return 0;
+ }
+
+ /*
+ * If a test has previously requested the diag318 info,
+ * then don't bother spinning up a temporary VM again.
+ */
+ if (!diag318_info)
+ diag318_info = diag318_handler();
+
+ return diag318_info;
+}
diff --git a/tools/testing/selftests/kvm/s390x/resets.c b/tools/testing/selftests/kvm/s390x/resets.c
index b143db6d8693..b3d7d4ac2d54 100644
--- a/tools/testing/selftests/kvm/s390x/resets.c
+++ b/tools/testing/selftests/kvm/s390x/resets.c
@@ -110,6 +110,7 @@ static void assert_clear(void)
TEST_ASSERT(!memcmp(sync_regs->vrs, regs_null, sizeof(sync_regs->vrs)),
"vrs0-15 == 0 (sync_regs)");
+
}
static void assert_initial_noclear(void)
diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
index 5731ccf34917..caf7b8859a94 100644
--- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
@@ -20,6 +20,7 @@
#include "test_util.h"
#include "kvm_util.h"
+#include "diag318_test_handler.h"
#define VCPU_ID 5
@@ -70,7 +71,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
#undef REG_COMPARE
-#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS)
+#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318)
#define INVALID_SYNC_FIELD 0x80000000
int main(int argc, char *argv[])
@@ -152,6 +153,12 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS;
run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS;
+
+ if (get_diag318_info() > 0) {
+ run->s.regs.diag318 = get_diag318_info();
+ run->kvm_dirty_regs |= KVM_SYNC_DIAG318;
+ }
+
rv = _vcpu_run(vm, VCPU_ID);
TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -164,6 +171,9 @@ int main(int argc, char *argv[])
TEST_ASSERT(run->s.regs.acrs[0] == 1 << 11,
"acr0 sync regs value incorrect 0x%x.",
run->s.regs.acrs[0]);
+ TEST_ASSERT(run->s.regs.diag318 == get_diag318_info(),
+ "diag318 sync regs value incorrect 0x%llx.",
+ run->s.regs.diag318);
vcpu_regs_get(vm, VCPU_ID, ®s);
compare_regs(®s, &run->s.regs);
@@ -177,6 +187,7 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS;
run->kvm_dirty_regs = 0;
run->s.regs.gprs[11] = 0xDEADBEEF;
+ run->s.regs.diag318 = 0x4B1D;
rv = _vcpu_run(vm, VCPU_ID);
TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -186,6 +197,9 @@ int main(int argc, char *argv[])
TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF,
"r11 sync regs value incorrect 0x%llx.",
run->s.regs.gprs[11]);
+ TEST_ASSERT(run->s.regs.diag318 != 0x4B1D,
+ "diag318 sync regs value incorrect 0x%llx.",
+ run->s.regs.diag318);
kvm_vm_free(vm);
--
2.26.2
This series adds support for transparent huge page migration to
migrate_vma_*() and adds nouveau SVM and HMM selftests as consumers.
Earlier versions were posted previously [1] and [2].
The patches apply cleanly to the linux-mm 5.10.0-rc2 tree. There are a
lot of other THP patches being posted. I don't think there are any
semantic conflicts but there may be some merge conflicts depending on
the order Andrew applies these.
Changes in v3:
Sent the patch ("mm/thp: fix __split_huge_pmd_locked() for migration PMD")
as a separate patch from this series.
Rebased to linux-mm 5.10.0-rc2.
Changes in v2:
Added splitting a THP midway in the migration process:
i.e., in migrate_vma_pages().
[1] https://lore.kernel.org/linux-mm/20200619215649.32297-1-rcampbell@nvidia.com
[2] https://lore.kernel.org/linux-mm/20200902165830.5367-1-rcampbell@nvidia.com
Ralph Campbell (6):
mm/thp: add prep_transhuge_device_private_page()
mm/migrate: move migrate_vma_collect_skip()
mm: support THP migration to device private memory
mm/thp: add THP allocation helper
mm/hmm/test: add self tests for THP migration
nouveau: support THP migration to private memory
drivers/gpu/drm/nouveau/nouveau_dmem.c | 289 +++++++++++-----
drivers/gpu/drm/nouveau/nouveau_svm.c | 11 +-
drivers/gpu/drm/nouveau/nouveau_svm.h | 3 +-
include/linux/gfp.h | 10 +
include/linux/huge_mm.h | 12 +
include/linux/memremap.h | 9 +
include/linux/migrate.h | 2 +
lib/test_hmm.c | 437 +++++++++++++++++++++----
lib/test_hmm_uapi.h | 3 +
mm/huge_memory.c | 147 +++++++--
mm/memcontrol.c | 25 +-
mm/memory.c | 10 +-
mm/memremap.c | 4 +-
mm/migrate.c | 429 +++++++++++++++++++-----
mm/rmap.c | 2 +-
tools/testing/selftests/vm/hmm-tests.c | 404 +++++++++++++++++++++++
16 files changed, 1522 insertions(+), 275 deletions(-)
--
2.20.1
This patchset provides support for the SRv6 End.DT4 and End.DT6 (VRF mode)
behaviors.
The SRv6 End.DT4 behavior is used to implement multi-tenant IPv4 L3 VPNs. It
decapsulates the received packets and performs IPv4 routing lookup in the
routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a
VRF device in order to force the routing lookup into the associated routing
table.
The SRv6 End.DT4 behavior is defined in the SRv6 Network Programming [1].
The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior
which allows us to set up IPv6 L3 VPNs over SRv6 networks. This new
implementation of DT6 is based on the same VRF infrastructure already exploited
for implementing the SRv6 End.DT4 behavior. The aim of the new SRv6 End.DT6 in
VRF mode consists in simplifying the construction of IPv6 L3 VPN services in
the multi-tenant environment.
Currently, the two SRv6 End.DT6 implementations (legacy and VRF mode)
coexist seamlessly and can be chosen according to the context and the user
preferences.
- Patch 1 is needed to solve a pre-existing issue with tunneled packets
when a sniffer is attached;
- Patch 2 improves the management of the seg6local attributes used by the
SRv6 behaviors;
- Patch 3 adds support for optional attributes in SRv6 behaviors;
- Patch 4 introduces two callbacks used for customizing the
creation/destruction of a SRv6 behavior;
- Patch 5 is the core patch that adds support for the SRv6 End.DT4
behavior;
- Patch 6 introduces the VRF support for SRv6 End.DT6 behavior;
- Patch 7 adds the selftest for SRv6 End.DT4 behavior;
- Patch 8 adds the selftest for SRv6 End.DT6 (VRF mode) behavior.
Regarding iproute2, the support for the new "vrftable" attribute, required by
both SRv6 End.DT4 and End.DT6 (VRF mode) behaviors, is provided in a different
patchset that will follow shortly.
I would like to thank David Ahern for his support during the development of
this patchset.
Comments, suggestions and improvements are very welcome!
Thanks,
Andrea Mayer
v4
seg6: add support for the SRv6 End.DT4 behavior
- remove IS_ERR() checks in cmp_nla_vrftable(), thanks to Jakub Kicinski.
remove patch for iproute2:
- mixing the iproute2 patch with this patchset confused patchwork.
v3
notes about the build bot:
- apparently the ',' (comma) in the subject prefix confused the build bot.
Removed the ',' in favor of ' ' (space).
Thanks to David Ahern and Konstantin Ryabitsev for shedding light on this
fact.
Thanks also to Nathan Chancellor for trying to build the patchset v2 by
simulating the bot issue.
add new patch for iproute2:
- [9/9] seg6: add support for vrftable attribute in End.DT4/DT6 behaviors
add new patch:
- [8/9] selftests: add selftest for the SRv6 End.DT6 (VRF) behavior
add new patch:
- [6/9] seg6: add VRF support for SRv6 End.DT6 behavior
add new patch:
- [3/9] seg6: add support for optional attributes in SRv6 behaviors
selftests: add selftest for the SRv6 End.DT4 behavior
- keep David Ahern's review tag since the code wasn't changed. Thanks to David
Ahern for his review.
seg6: add support for the SRv6 End.DT4 behavior
- remove useless error in seg6_end_dt4_build();
- remove #ifdef/#endif stubs for DT4 when CONFIG_NET_L3_MASTER_DEV is not
defined;
- fix coding style.
Thanks to Jakub Kicinski for his review and for all his suggestions.
seg6: add callbacks for customizing the creation/destruction of a behavior
- remove typedef(s) slwt_{build/destroy}_state_t;
- fix coding style: remove empty lines, trivial comments and rename labels in
the seg6_local_build_state() function.
Thanks to Jakub Kicinski for his review and for all his suggestions.
seg6: improve management of behavior attributes
- remove defensive programming approach in destroy_attr_srh(),
destroy_attr_bpf() and destroy_attrs();
- change the __destroy_attrs() function signature, renaming the 'end' argument
'parsed_max'. Now, the __destroy_attrs() keeps only the 'parsed_max' and
'slwt' arguments.
Thanks to Jakub Kicinski for his review and for all his suggestions.
vrf: add mac header for tunneled packets when sniffer is attached
- keep David Ahern's review tag since the code wasn't changed.
Thanks to Jakub Kicinski for pointing it out and David Ahern for his review.
v2
no changes made: resubmitted after false build report.
v1
improve comments;
add new patch 2/5 titled: seg6: improve management of behavior attributes
seg6: add support for the SRv6 End.DT4 behavior
- remove the inline keyword in the definition of fib6_config_get_net().
selftests: add selftest for the SRv6 End.DT4 behavior
- add check for the vrf sysctl
[1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming
Andrea Mayer (8):
vrf: add mac header for tunneled packets when sniffer is attached
seg6: improve management of behavior attributes
seg6: add support for optional attributes in SRv6 behaviors
seg6: add callbacks for customizing the creation/destruction of a
behavior
seg6: add support for the SRv6 End.DT4 behavior
seg6: add VRF support for SRv6 End.DT6 behavior
selftests: add selftest for the SRv6 End.DT4 behavior
selftests: add selftest for the SRv6 End.DT6 (VRF) behavior
drivers/net/vrf.c | 78 ++-
include/uapi/linux/seg6_local.h | 1 +
net/ipv6/seg6_local.c | 590 +++++++++++++++++-
.../selftests/net/srv6_end_dt4_l3vpn_test.sh | 494 +++++++++++++++
.../selftests/net/srv6_end_dt6_l3vpn_test.sh | 502 +++++++++++++++
5 files changed, 1646 insertions(+), 19 deletions(-)
create mode 100755 tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh
create mode 100755 tools/testing/selftests/net/srv6_end_dt6_l3vpn_test.sh
--
2.20.1
The error handling in hugetlb_allocate_area() was incorrect for the
hugetlb_shared test case.
Previously the behavior was:
- mmap a hugetlb area
- If this fails, set the pointer to NULL, and carry on
- mmap an alias of the same hugetlb fd
- If this fails, munmap the original area
If the original mmap failed, it's likely the second one did too. If
both failed, we'd blindly try to munmap a NULL pointer, causing a
SIGSEGV. Instead, "goto fail" so we return before trying to mmap the
alias.
This issue can be hit "in real life" by forgetting to set
/proc/sys/vm/nr_hugepages (leaving it at 0), and then trying to run the
hugetlb_shared test.
Another small improvement is, when the original mmap fails, don't just
print "it failed": perror(), so we can see *why*. :)
Signed-off-by: Axel Rasmussen <axelrasmussen(a)google.com>
---
tools/testing/selftests/vm/userfaultfd.c | 25 +++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 9b0912a01777..c4425597769a 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -206,19 +206,19 @@ static int hugetlb_release_pages(char *rel_area)
return ret;
}
-
static void hugetlb_allocate_area(void **alloc_area)
{
void *area_alias = NULL;
char **alloc_area_alias;
+
*alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
(map_shared ? MAP_SHARED : MAP_PRIVATE) |
MAP_HUGETLB,
huge_fd, *alloc_area == area_src ? 0 :
nr_pages * page_size);
if (*alloc_area == MAP_FAILED) {
- fprintf(stderr, "mmap of hugetlbfs file failed\n");
- *alloc_area = NULL;
+ perror("mmap of hugetlbfs file failed");
+ goto fail;
}
if (map_shared) {
@@ -227,14 +227,11 @@ static void hugetlb_allocate_area(void **alloc_area)
huge_fd, *alloc_area == area_src ? 0 :
nr_pages * page_size);
if (area_alias == MAP_FAILED) {
- if (munmap(*alloc_area, nr_pages * page_size) < 0) {
- perror("hugetlb munmap");
- exit(1);
- }
- *alloc_area = NULL;
- return;
+ perror("mmap of hugetlb file alias failed");
+ goto fail_munmap;
}
}
+
if (*alloc_area == area_src) {
huge_fd_off0 = *alloc_area;
alloc_area_alias = &area_src_alias;
@@ -243,6 +240,16 @@ static void hugetlb_allocate_area(void **alloc_area)
}
if (area_alias)
*alloc_area_alias = area_alias;
+
+ return;
+
+fail_munmap:
+ if (munmap(*alloc_area, nr_pages * page_size) < 0) {
+ perror("hugetlb munmap");
+ exit(1);
+ }
+fail:
+ *alloc_area = NULL;
}
static void hugetlb_alias_mapping(__u64 *start, size_t len, unsigned long offset)
--
2.29.2.576.ga3fc446d84-goog