From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
Both $comm and $COMM can be used to get current->comm in eprobes and the
filtering and histogram logic. Make kprobes and uprobes consistent in this
regard and allow both $comm and $COMM as well. Currently kprobes and
uprobes only handle $comm, which is inconsistent with the other utilities,
and can be confusing to users.
Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.…
Cc: stable(a)vger.kernel.org
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Suggested-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/trace_probe.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 4daabbb8b772..36dff277de46 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -314,7 +314,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
}
} else
goto inval_var;
- } else if (strcmp(arg, "comm") == 0) {
+ } else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
code->op = FETCH_OP_COMM;
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
} else if (((flags & TPARG_FL_MASK) ==
@@ -625,7 +625,8 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
* we can find those by strcmp. But ignore for eprobes.
*/
if (!(flags & TPARG_FL_TPOINT) &&
- (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0)) {
+ (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
+ strncmp(arg, "\\\"", 2) == 0)) {
/* The type of $comm must be "string", and not an array. */
if (parg->count || (t && strcmp(t, "string")))
goto out;
--
2.35.1
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
Currently, if a symbol "@" is attempted to be used with an event probe
(eprobes), it will cause a NULL pointer dereference crash.
Both kprobes and uprobes can reference data other than the main registers.
Such as immediate address, symbols and the current task name. Have eprobes
do the same thing.
For "comm", if "comm" is used and the event being attached to does not
have the "comm" field, then make it the "$comm" that kprobes has. This is
consistent to the way histograms and filters work.
Cc: stable(a)vger.kernel.org
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/trace_eprobe.c | 70 +++++++++++++++++++++++++++++++++----
1 file changed, 64 insertions(+), 6 deletions(-)
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index a1d3423ab74f..1783e3478912 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -227,6 +227,7 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i)
struct probe_arg *parg = &ep->tp.args[i];
struct ftrace_event_field *field;
struct list_head *head;
+ int ret = -ENOENT;
head = trace_get_fields(ep->event);
list_for_each_entry(field, head, link) {
@@ -236,9 +237,20 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i)
return 0;
}
}
+
+ /*
+ * Argument not found on event. But allow for comm and COMM
+ * to be used to get the current->comm.
+ */
+ if (strcmp(parg->code->data, "COMM") == 0 ||
+ strcmp(parg->code->data, "comm") == 0) {
+ parg->code->op = FETCH_OP_COMM;
+ ret = 0;
+ }
+
kfree(parg->code->data);
parg->code->data = NULL;
- return -ENOENT;
+ return ret;
}
static int eprobe_event_define_fields(struct trace_event_call *event_call)
@@ -363,16 +375,38 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec)
static int get_eprobe_size(struct trace_probe *tp, void *rec)
{
+ struct fetch_insn *code;
struct probe_arg *arg;
int i, len, ret = 0;
for (i = 0; i < tp->nr_args; i++) {
arg = tp->args + i;
- if (unlikely(arg->dynamic)) {
+ if (arg->dynamic) {
unsigned long val;
- val = get_event_field(arg->code, rec);
- len = process_fetch_insn_bottom(arg->code + 1, val, NULL, NULL);
+ code = arg->code;
+ retry:
+ switch (code->op) {
+ case FETCH_OP_TP_ARG:
+ val = get_event_field(code, rec);
+ break;
+ case FETCH_OP_IMM:
+ val = code->immediate;
+ break;
+ case FETCH_OP_COMM:
+ val = (unsigned long)current->comm;
+ break;
+ case FETCH_OP_DATA:
+ val = (unsigned long)code->data;
+ break;
+ case FETCH_NOP_SYMBOL: /* Ignore a place holder */
+ code++;
+ goto retry;
+ default:
+ continue;
+ }
+ code++;
+ len = process_fetch_insn_bottom(code, val, NULL, NULL);
if (len > 0)
ret += len;
}
@@ -390,8 +424,28 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
{
unsigned long val;
- val = get_event_field(code, rec);
- return process_fetch_insn_bottom(code + 1, val, dest, base);
+ retry:
+ switch (code->op) {
+ case FETCH_OP_TP_ARG:
+ val = get_event_field(code, rec);
+ break;
+ case FETCH_OP_IMM:
+ val = code->immediate;
+ break;
+ case FETCH_OP_COMM:
+ val = (unsigned long)current->comm;
+ break;
+ case FETCH_OP_DATA:
+ val = (unsigned long)code->data;
+ break;
+ case FETCH_NOP_SYMBOL: /* Ignore a place holder */
+ code++;
+ goto retry;
+ default:
+ return -EILSEQ;
+ }
+ code++;
+ return process_fetch_insn_bottom(code, val, dest, base);
}
NOKPROBE_SYMBOL(process_fetch_insn)
@@ -866,6 +920,10 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[
trace_probe_log_err(0, BAD_ATTACH_ARG);
}
+ /* Handle symbols "@" */
+ if (!ret)
+ ret = traceprobe_update_arg(&ep->tp.args[i]);
+
return ret;
}
--
2.35.1
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
Currently when an event probe (eprobe) hooks to a string field, it does
not display it as a string, but instead as a number. This makes the field
rather useless. Handle the different kinds of strings, dynamic, static,
relational/dynamic etc.
Now when a string field is used, the ":string" type can be used to display
it:
echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events
Cc: stable(a)vger.kernel.org
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/trace_eprobe.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 550671985fd1..a1d3423ab74f 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -311,6 +311,27 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec)
addr = rec + field->offset;
+ if (is_string_field(field)) {
+ switch (field->filter_type) {
+ case FILTER_DYN_STRING:
+ val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff));
+ break;
+ case FILTER_RDYN_STRING:
+ val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff));
+ break;
+ case FILTER_STATIC_STRING:
+ val = (unsigned long)addr;
+ break;
+ case FILTER_PTR_STRING:
+ val = (unsigned long)(*(char *)addr);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+ return val;
+ }
+
switch (field->size) {
case 1:
if (field->is_signed)
--
2.35.1
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
The variable $comm is hard coded as a string, which is true for both
kprobes and uprobes, but for event probes (eprobes) it is a field name. In
most cases the "comm" field would be a string, but there's no guarantee of
that fact.
Do not assume that comm is a string. Not to mention, it currently forces
comm fields to fault, as string processing for event probes is currently
broken.
Cc: stable(a)vger.kernel.org
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/trace_probe.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index dec657af363c..4daabbb8b772 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -622,9 +622,10 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
/*
* Since $comm and immediate string can not be dereferenced,
- * we can find those by strcmp.
+ * we can find those by strcmp. But ignore for eprobes.
*/
- if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) {
+ if (!(flags & TPARG_FL_TPOINT) &&
+ (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0)) {
/* The type of $comm must be "string", and not an array. */
if (parg->count || (t && strcmp(t, "string")))
goto out;
--
2.35.1
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
If in perf_trace_event_init(), the perf_trace_event_open() fails, then it
will call perf_trace_event_unreg() which will not only unregister the perf
trace event, but will also call the put() function of the tp_event.
The problem here is that the trace_event_try_get_ref() is called by the
caller of perf_trace_event_init() and if perf_trace_event_init() returns a
failure, it will then call trace_event_put(). But since the
perf_trace_event_unreg() already called the trace_event_put() function, it
triggers a WARN_ON().
WARNING: CPU: 1 PID: 30309 at kernel/trace/trace_dynevent.c:46 trace_event_dyn_put_ref+0x15/0x20
If perf_trace_event_reg() does not call the trace_event_try_get_ref() then
the perf_trace_event_unreg() should not be calling trace_event_put(). This
breaks symmetry and causes bugs like these.
Pull out the trace_event_put() from perf_trace_event_unreg() and call it
in the locations that perf_trace_event_unreg() is called. This not only
fixes this bug, but also brings back the proper symmetry of the reg/unreg
vs get/put logic.
Link: https://lore.kernel.org/all/cover.1660347763.git.kjlx@templeofstupid.com/
Link: https://lkml.kernel.org/r/20220816192817.43d5e17f@gandalf.local.home
Cc: stable(a)vger.kernel.org
Fixes: 1d18538e6a092 ("tracing: Have dynamic events have a ref counter")
Reported-by: Krister Johansen <kjlx(a)templeofstupid.com>
Reviewed-by: Krister Johansen <kjlx(a)templeofstupid.com>
Tested-by: Krister Johansen <kjlx(a)templeofstupid.com>
Acked-by: Jiri Olsa <jolsa(a)kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
kernel/trace/trace_event_perf.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index a114549720d6..61e3a2620fa3 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -157,7 +157,7 @@ static void perf_trace_event_unreg(struct perf_event *p_event)
int i;
if (--tp_event->perf_refcount > 0)
- goto out;
+ return;
tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER, NULL);
@@ -176,8 +176,6 @@ static void perf_trace_event_unreg(struct perf_event *p_event)
perf_trace_buf[i] = NULL;
}
}
-out:
- trace_event_put_ref(tp_event);
}
static int perf_trace_event_open(struct perf_event *p_event)
@@ -241,6 +239,7 @@ void perf_trace_destroy(struct perf_event *p_event)
mutex_lock(&event_mutex);
perf_trace_event_close(p_event);
perf_trace_event_unreg(p_event);
+ trace_event_put_ref(p_event->tp_event);
mutex_unlock(&event_mutex);
}
@@ -292,6 +291,7 @@ void perf_kprobe_destroy(struct perf_event *p_event)
mutex_lock(&event_mutex);
perf_trace_event_close(p_event);
perf_trace_event_unreg(p_event);
+ trace_event_put_ref(p_event->tp_event);
mutex_unlock(&event_mutex);
destroy_local_trace_kprobe(p_event->tp_event);
@@ -347,6 +347,7 @@ void perf_uprobe_destroy(struct perf_event *p_event)
mutex_lock(&event_mutex);
perf_trace_event_close(p_event);
perf_trace_event_unreg(p_event);
+ trace_event_put_ref(p_event->tp_event);
mutex_unlock(&event_mutex);
destroy_local_trace_uprobe(p_event->tp_event);
}
--
2.35.1
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7ef3d06f1bc4a5e62273726f3dc2bd258ae1c71f Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason(a)zx2c4.com>
Date: Thu, 28 Jul 2022 00:32:18 +1000
Subject: [PATCH] powerpc/powernv/kvm: Use darn for H_RANDOM on Power9
The existing logic in KVM to support guests calling H_RANDOM only works
on Power8, because it looks for an RNG in the device tree, but on Power9
we just use darn.
In addition the existing code needs to work in real mode, so we have the
special cased powernv_get_random_real_mode() to deal with that.
Instead just have KVM call ppc_md.get_random_seed(), and do the real
mode check inside of there, that way we use whatever RNG is available,
including darn on Power9.
Fixes: e928e9cb3601 ("KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.")
Cc: stable(a)vger.kernel.org # v4.1+
Signed-off-by: Jason A. Donenfeld <Jason(a)zx2c4.com>
Tested-by: Sachin Sant <sachinp(a)linux.ibm.com>
[mpe: Rebase on previous commit, update change log appropriately]
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/20220727143219.2684192-2-mpe@ellerman.id.au
diff --git a/arch/powerpc/include/asm/archrandom.h b/arch/powerpc/include/asm/archrandom.h
index 9a53e29680f4..258174304904 100644
--- a/arch/powerpc/include/asm/archrandom.h
+++ b/arch/powerpc/include/asm/archrandom.h
@@ -38,12 +38,7 @@ static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
#endif /* CONFIG_ARCH_RANDOM */
#ifdef CONFIG_PPC_POWERNV
-int powernv_hwrng_present(void);
int powernv_get_random_long(unsigned long *v);
-int powernv_get_random_real_mode(unsigned long *v);
-#else
-static inline int powernv_hwrng_present(void) { return 0; }
-static inline int powernv_get_random_real_mode(unsigned long *v) { return 0; }
#endif
#endif /* _ASM_POWERPC_ARCHRANDOM_H */
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 88a8f6473c4e..3abaef5f9ac2 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -19,7 +19,7 @@
#include <asm/interrupt.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
-#include <asm/archrandom.h>
+#include <asm/machdep.h>
#include <asm/xics.h>
#include <asm/xive.h>
#include <asm/dbell.h>
@@ -176,13 +176,14 @@ EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode);
int kvmppc_hwrng_present(void)
{
- return powernv_hwrng_present();
+ return ppc_md.get_random_seed != NULL;
}
EXPORT_SYMBOL_GPL(kvmppc_hwrng_present);
long kvmppc_rm_h_random(struct kvm_vcpu *vcpu)
{
- if (powernv_get_random_real_mode(&vcpu->arch.regs.gpr[4]))
+ if (ppc_md.get_random_seed &&
+ ppc_md.get_random_seed(&vcpu->arch.regs.gpr[4]))
return H_SUCCESS;
return H_HARDWARE;
diff --git a/arch/powerpc/platforms/powernv/rng.c b/arch/powerpc/platforms/powernv/rng.c
index 2287c9cd0cd5..d19305292e1e 100644
--- a/arch/powerpc/platforms/powernv/rng.c
+++ b/arch/powerpc/platforms/powernv/rng.c
@@ -29,15 +29,6 @@ struct powernv_rng {
static DEFINE_PER_CPU(struct powernv_rng *, powernv_rng);
-int powernv_hwrng_present(void)
-{
- struct powernv_rng *rng;
-
- rng = get_cpu_var(powernv_rng);
- put_cpu_var(rng);
- return rng != NULL;
-}
-
static unsigned long rng_whiten(struct powernv_rng *rng, unsigned long val)
{
unsigned long parity;
@@ -58,19 +49,6 @@ static unsigned long rng_whiten(struct powernv_rng *rng, unsigned long val)
return val;
}
-int powernv_get_random_real_mode(unsigned long *v)
-{
- struct powernv_rng *rng;
-
- rng = raw_cpu_read(powernv_rng);
- if (!rng)
- return 0;
-
- *v = rng_whiten(rng, __raw_rm_readq(rng->regs_real));
-
- return 1;
-}
-
static int powernv_get_random_darn(unsigned long *v)
{
unsigned long val;
@@ -107,12 +85,14 @@ int powernv_get_random_long(unsigned long *v)
{
struct powernv_rng *rng;
- rng = get_cpu_var(powernv_rng);
-
- *v = rng_whiten(rng, in_be64(rng->regs));
-
- put_cpu_var(rng);
-
+ if (mfmsr() & MSR_DR) {
+ rng = get_cpu_var(powernv_rng);
+ *v = rng_whiten(rng, in_be64(rng->regs));
+ put_cpu_var(rng);
+ } else {
+ rng = raw_cpu_read(powernv_rng);
+ *v = rng_whiten(rng, __raw_rm_readq(rng->regs_real));
+ }
return 1;
}
EXPORT_SYMBOL_GPL(powernv_get_random_long);
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0d519cadf75184a24313568e7f489a7fc9b1be3b Mon Sep 17 00:00:00 2001
From: Coiby Xu <coxu(a)redhat.com>
Date: Thu, 14 Jul 2022 21:40:26 +0800
Subject: [PATCH] arm64: kexec_file: use more system keyrings to verify kernel
image signature
Currently, when loading a kernel image via the kexec_file_load() system
call, arm64 can only use the .builtin_trusted_keys keyring to verify
a signature whereas x86 can use three more keyrings i.e.
.secondary_trusted_keys, .machine and .platform keyrings. For example,
one resulting problem is kexec'ing a kernel image would be rejected
with the error "Lockdown: kexec: kexec of unsigned images is restricted;
see man kernel_lockdown.7".
This patch set enables arm64 to make use of the same keyrings as x86 to
verify the signature kexec'ed kernel image.
Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support")
Cc: stable(a)vger.kernel.org # 105e10e2cf1c: kexec_file: drop weak attribute from functions
Cc: stable(a)vger.kernel.org # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig
Cc: stable(a)vger.kernel.org # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic
Acked-by: Baoquan He <bhe(a)redhat.com>
Cc: kexec(a)lists.infradead.org
Cc: keyrings(a)vger.kernel.org
Cc: linux-security-module(a)vger.kernel.org
Co-developed-by: Michal Suchanek <msuchanek(a)suse.de>
Signed-off-by: Michal Suchanek <msuchanek(a)suse.de>
Acked-by: Will Deacon <will(a)kernel.org>
Signed-off-by: Coiby Xu <coxu(a)redhat.com>
Signed-off-by: Mimi Zohar <zohar(a)linux.ibm.com>
diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
index 9ec34690e255..5ed6a585f21f 100644
--- a/arch/arm64/kernel/kexec_image.c
+++ b/arch/arm64/kernel/kexec_image.c
@@ -14,7 +14,6 @@
#include <linux/kexec.h>
#include <linux/pe.h>
#include <linux/string.h>
-#include <linux/verification.h>
#include <asm/byteorder.h>
#include <asm/cpufeature.h>
#include <asm/image.h>
@@ -130,18 +129,10 @@ static void *image_load(struct kimage *image,
return NULL;
}
-#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
-static int image_verify_sig(const char *kernel, unsigned long kernel_len)
-{
- return verify_pefile_signature(kernel, kernel_len, NULL,
- VERIFYING_KEXEC_PE_SIGNATURE);
-}
-#endif
-
const struct kexec_file_ops kexec_image_ops = {
.probe = image_probe,
.load = image_load,
#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
- .verify_sig = image_verify_sig,
+ .verify_sig = kexec_kernel_verify_pe_sig,
#endif
};