From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
dja@axtens.net, Spoorthy S <spoorts2@in.ibm.com>,
Russell Currey <ruscur@russell.cc>
Subject: [PATCH 5.4 01/17] selftests/powerpc: rfi_flush: disable entry flush if present
Date: Fri, 20 Nov 2020 12:03:28 +0100 [thread overview]
Message-ID: <20201120104541.136752834@linuxfoundation.org> (raw)
In-Reply-To: <20201120104541.058449969@linuxfoundation.org>
From: Russell Currey <ruscur@russell.cc>
commit fcb48454c23c5679d1a2e252f127642e91b05cbe upstream.
We are about to add an entry flush. The rfi (exit) flush test measures
the number of L1D flushes over a syscall with the RFI flush enabled and
disabled. But if the entry flush is also enabled, the effect of enabling
and disabling the RFI flush is masked.
If there is a debugfs entry for the entry flush, disable it during the RFI
flush and restore it later.
Reported-by: Spoorthy S <spoorts2@in.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/testing/selftests/powerpc/security/rfi_flush.c | 35 +++++++++++++++----
1 file changed, 29 insertions(+), 6 deletions(-)
--- a/tools/testing/selftests/powerpc/security/rfi_flush.c
+++ b/tools/testing/selftests/powerpc/security/rfi_flush.c
@@ -50,16 +50,30 @@ int rfi_flush_test(void)
__u64 l1d_misses_total = 0;
unsigned long iterations = 100000, zero_size = 24 * 1024;
unsigned long l1d_misses_expected;
- int rfi_flush_org, rfi_flush;
+ int rfi_flush_orig, rfi_flush;
+ int have_entry_flush, entry_flush_orig;
SKIP_IF(geteuid() != 0);
- if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_org)) {
+ if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
perror("Unable to read powerpc/rfi_flush debugfs file");
SKIP_IF(1);
}
- rfi_flush = rfi_flush_org;
+ if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
+ have_entry_flush = 0;
+ } else {
+ have_entry_flush = 1;
+
+ if (entry_flush_orig != 0) {
+ if (write_debugfs_file("powerpc/entry_flush", 0) < 0) {
+ perror("error writing to powerpc/entry_flush debugfs file");
+ return 1;
+ }
+ }
+ }
+
+ rfi_flush = rfi_flush_orig;
fd = perf_event_open_counter(PERF_TYPE_RAW, /* L1d miss */ 0x400f0, -1);
FAIL_IF(fd < 0);
@@ -68,6 +82,7 @@ int rfi_flush_test(void)
FAIL_IF(perf_event_enable(fd));
+ // disable L1 prefetching
set_dscr(1);
iter = repetitions;
@@ -109,8 +124,8 @@ again:
repetitions * l1d_misses_expected / 2,
passes, repetitions);
- if (rfi_flush == rfi_flush_org) {
- rfi_flush = !rfi_flush_org;
+ if (rfi_flush == rfi_flush_orig) {
+ rfi_flush = !rfi_flush_orig;
if (write_debugfs_file("powerpc/rfi_flush", rfi_flush) < 0) {
perror("error writing to powerpc/rfi_flush debugfs file");
return 1;
@@ -126,11 +141,19 @@ again:
set_dscr(0);
- if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_org) < 0) {
+ if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
perror("unable to restore original value of powerpc/rfi_flush debugfs file");
return 1;
}
+ if (have_entry_flush) {
+ if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
+ perror("unable to restore original value of powerpc/entry_flush "
+ "debugfs file");
+ return 1;
+ }
+ }
+
return rc;
}
next prev parent reply other threads:[~2020-11-20 11:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 11:03 [PATCH 5.4 00/17] 5.4.79-rc1 review Greg Kroah-Hartman
2020-11-20 11:03 ` Greg Kroah-Hartman [this message]
2020-11-20 11:03 ` [PATCH 5.4 02/17] powerpc/64s: flush L1D on kernel entry Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 03/17] powerpc/64s: flush L1D after user accesses Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 04/17] powerpc: Only include kup-radix.h for 64-bit Book3S Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 05/17] selftests/powerpc: entry flush test Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 06/17] MIPS: PCI: Fix MIPS build Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 07/17] net/mlx5: Use async EQ setup cleanup helpers for multiple EQs Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 08/17] net/mlx5: poll cmd EQ in case of command timeout Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 09/17] net/mlx5: Fix a race when moving command interface to events mode Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 10/17] net/mlx5: Add retry mechanism to the command entry index allocation Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 11/17] powerpc/8xx: Always fault when _PAGE_ACCESSED is not set Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 12/17] net: lantiq: Add locking for TX DMA channel Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 13/17] Input: sunkbd - avoid use-after-free in teardown paths Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 14/17] mac80211: always wind down STA state Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 15/17] can: proc: can_remove_proc(): silence remove_proc_entry warning Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 16/17] KVM: x86: clflushopt should be treated as a no-op by emulation Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 5.4 17/17] ACPI: GED: fix -Wformat Greg Kroah-Hartman
2020-11-20 16:56 ` [PATCH 5.4 00/17] 5.4.79-rc1 review Jon Hunter
2020-11-20 22:28 ` Shuah Khan
2020-11-21 11:48 ` Naresh Kamboju
2020-11-21 18:37 ` Guenter Roeck
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