@@ -1,9 +1,9 @@
// SPDX-License-Identifier: GPL-2.0+
-#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
+#include <sys/prctl.h>
#include "dexcr.h"
#include "utils.h"
@@ -16,6 +16,8 @@ struct dexcr_aspect {
const char *name;
const char *desc;
unsigned int index;
+ unsigned long prctl;
+ const char *sysctl;
};
static const struct dexcr_aspect aspects[] = {
@@ -23,26 +25,36 @@ static const struct dexcr_aspect aspects[] = {
.name = "SBHE",
.desc = "Speculative branch hint enable",
.index = 0,
+ .prctl = PR_PPC_DEXCR_SBHE,
+ .sysctl = "speculative_branch_hint_enable",
},
{
.name = "IBRTPD",
.desc = "Indirect branch recurrent target prediction disable",
.index = 3,
+ .prctl = PR_PPC_DEXCR_IBRTPD,
+ .sysctl = "indirect_branch_recurrent_target_prediction_disable",
},
{
.name = "SRAPD",
.desc = "Subroutine return address prediction disable",
.index = 4,
+ .prctl = PR_PPC_DEXCR_SRAPD,
+ .sysctl = "subroutine_return_address_prediction_disable",
},
{
.name = "NPHIE",
.desc = "Non-privileged hash instruction enable",
.index = 5,
+ .prctl = PR_PPC_DEXCR_NPHIE,
+ .sysctl = "nonprivileged_hash_instruction_enable",
},
{
.name = "PHIE",
.desc = "Privileged hash instruction enable",
.index = 6,
+ .prctl = -1,
+ .sysctl = NULL,
},
};
@@ -60,7 +72,7 @@ static void print_dexcr(char *name, unsigned int bits)
const char *enabled_aspects[ARRAY_SIZE(aspects) + 1] = {NULL};
size_t j = 0;
- printf("%s: %08x", name, bits);
+ printf("%s: 0x%08x", name, bits);
if (bits == 0) {
printf("\n");
@@ -103,6 +115,95 @@ static void print_aspect(const struct dexcr_aspect *aspect)
printf(" \t(%s)\n", aspect->desc);
}
+static void print_aspect_config(const struct dexcr_aspect *aspect)
+{
+ char sysctl_path[128] = "/proc/sys/kernel/dexcr/";
+ const char *reason = "unknown";
+ const char *reason_hyp = NULL;
+ const char *reason_sysctl = "no sysctl";
+ const char *reason_prctl = "no prctl";
+ bool actual = effective & DEXCR_PR_BIT(aspect->index);
+ bool expected = false;
+
+ long sysctl_ctrl = 0;
+ int prctl_ctrl = 0;
+ int err;
+
+ if (aspect->prctl >= 0) {
+ prctl_ctrl = pr_get_dexcr(aspect->prctl);
+ if (prctl_ctrl < 0)
+ reason_prctl = "(failed to read prctl)";
+ else {
+ if (prctl_ctrl & PR_PPC_DEXCR_CTRL_SET) {
+ reason_prctl = "set by prctl";
+ expected = true;
+ } else if (prctl_ctrl & PR_PPC_DEXCR_CTRL_CLEAR) {
+ reason_prctl = "cleared by prctl";
+ expected = false;
+ } else
+ reason_prctl = "unknown prctl";
+
+ reason = reason_prctl;
+ }
+ }
+
+ if (aspect->sysctl) {
+ strcat(sysctl_path, aspect->sysctl);
+ err = read_long(sysctl_path, &sysctl_ctrl, 10);
+ if (err)
+ reason_sysctl = "(failed to read sysctl)";
+ else {
+ switch (sysctl_ctrl) {
+ case 0:
+ reason_sysctl = "cleared by sysctl";
+ reason = reason_sysctl;
+ expected = false;
+ break;
+ case 1:
+ reason_sysctl = "set by sysctl";
+ reason = reason_sysctl;
+ expected = true;
+ break;
+ case 2:
+ reason_sysctl = "not modified by sysctl";
+ break;
+ case 3:
+ reason_sysctl = "cleared by sysctl (permanent)";
+ reason = reason_sysctl;
+ expected = false;
+ break;
+ case 4:
+ reason_sysctl = "set by sysctl (permanent)";
+ reason = reason_sysctl;
+ expected = true;
+ break;
+ default:
+ reason_sysctl = "unknown sysctl";
+ break;
+ }
+ }
+ }
+
+
+ if (hdexcr & DEXCR_PR_BIT(aspect->index)) {
+ reason_hyp = "set by hypervisor";
+ reason = reason_hyp;
+ expected = true;
+ } else
+ reason_hyp = "not modified by hypervisor";
+
+ printf("%12s (%d): %-28s (%s, %s, %s)\n",
+ aspect->name,
+ aspect->index,
+ reason,
+ reason_hyp,
+ reason_sysctl,
+ reason_prctl);
+
+ if (actual != expected)
+ printf(" : ! actual %s does not match config\n", aspect->name);
+}
+
int main(int argc, char *argv[])
{
if (!dexcr_exists()) {
@@ -114,6 +215,8 @@ int main(int argc, char *argv[])
hdexcr = get_dexcr(HDEXCR);
effective = dexcr | hdexcr;
+ printf("current status:\n");
+
print_dexcr(" DEXCR", dexcr);
print_dexcr(" HDEXCR", hdexcr);
print_dexcr("Effective", effective);
@@ -136,6 +239,12 @@ int main(int argc, char *argv[])
else
printf("ignored\n");
}
+ printf("\n");
+
+ printf("configuration:\n");
+ for (size_t i = 0; i < ARRAY_SIZE(aspects); i++)
+ print_aspect_config(&aspects[i]);
+ printf("\n");
return 0;
}
Now that the DEXCR can be configured with prctl, add a section in lsdexcr that explains why each aspect is set the way it is. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> --- .../testing/selftests/powerpc/dexcr/lsdexcr.c | 113 +++++++++++++++++- 1 file changed, 111 insertions(+), 2 deletions(-)