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authorLinus Torvalds <torvalds@linux-foundation.org>2026-07-05 05:34:43 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2026-07-05 05:34:43 -1000
commitc10dc5c03e17a9502325f3f49721a6058d162048 (patch)
treee393af5a43ba67fadb80dd24f900d9dd262cf528
parentfe5881ed7293813e492ad165292ae652b676ff6c (diff)
parent169328645663bae30e9abad4012d52441e085a71 (diff)
downloadlinux-2.6-c10dc5c03e17a9502325f3f49721a6058d162048.tar.gz
linux-2.6-c10dc5c03e17a9502325f3f49721a6058d162048.zip
Merge tag 'perf-urgent-2026-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events fixes from Ingo Molnar: - Fix a perf_event_attr::remove_on_exec bug for group events (Taeyang Lee) - Fix uprobes CALL emulation interaction with shadow stacks, and add a testcase for this (David Windsor) - Fix uprobes unregister bug (Jiri Olsa) * tag 'perf-urgent-2026-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: uprobes/x86: Use proper mm_struct in __in_uprobe_trampoline selftests/x86: Add shadow stack uprobe CALL test x86/uprobes: Keep shadow stack in sync for emulated CALLs perf/core: Detach event groups during remove_on_exec
-rw-r--r--arch/x86/kernel/uprobes.c26
-rw-r--r--kernel/events/core.c17
-rw-r--r--tools/testing/selftests/x86/test_shadow_stack.c86
3 files changed, 113 insertions, 16 deletions
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index ebb1baf1eb1d..3af979fb41d3 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -761,9 +761,9 @@ void arch_uprobe_clear_state(struct mm_struct *mm)
destroy_uprobe_trampoline(tramp);
}
-static bool __in_uprobe_trampoline(unsigned long ip)
+static bool __in_uprobe_trampoline(struct mm_struct *mm, unsigned long ip)
{
- struct vm_area_struct *vma = vma_lookup(current->mm, ip);
+ struct vm_area_struct *vma = vma_lookup(mm, ip);
return vma && vma_is_special_mapping(vma, &tramp_mapping);
}
@@ -776,14 +776,14 @@ static bool in_uprobe_trampoline(unsigned long ip)
rcu_read_lock();
if (mmap_lock_speculate_try_begin(mm, &seq)) {
- found = __in_uprobe_trampoline(ip);
+ found = __in_uprobe_trampoline(mm, ip);
retry = mmap_lock_speculate_retry(mm, seq);
}
rcu_read_unlock();
if (retry) {
mmap_read_lock(mm);
- found = __in_uprobe_trampoline(ip);
+ found = __in_uprobe_trampoline(mm, ip);
mmap_read_unlock(mm);
}
return found;
@@ -1044,7 +1044,7 @@ static int copy_from_vaddr(struct mm_struct *mm, unsigned long vaddr, void *dst,
return 0;
}
-static bool __is_optimized(uprobe_opcode_t *insn, unsigned long vaddr)
+static bool __is_optimized(struct mm_struct *mm, uprobe_opcode_t *insn, unsigned long vaddr)
{
struct __packed __arch_relative_insn {
u8 op;
@@ -1053,7 +1053,7 @@ static bool __is_optimized(uprobe_opcode_t *insn, unsigned long vaddr)
if (!is_call_insn(insn))
return false;
- return __in_uprobe_trampoline(vaddr + 5 + call->raddr);
+ return __in_uprobe_trampoline(mm, vaddr + 5 + call->raddr);
}
static int is_optimized(struct mm_struct *mm, unsigned long vaddr)
@@ -1064,7 +1064,7 @@ static int is_optimized(struct mm_struct *mm, unsigned long vaddr)
err = copy_from_vaddr(mm, vaddr, &insn, 5);
if (err)
return err;
- return __is_optimized((uprobe_opcode_t *)&insn, vaddr);
+ return __is_optimized(mm, (uprobe_opcode_t *)&insn, vaddr);
}
static bool should_optimize(struct arch_uprobe *auprobe)
@@ -1246,9 +1246,15 @@ static int default_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs
long correction = utask->vaddr - utask->xol_vaddr;
regs->ip += correction;
} else if (auprobe->defparam.fixups & UPROBE_FIX_CALL) {
+ unsigned long retaddr = utask->vaddr + auprobe->defparam.ilen;
+ int err;
+
regs->sp += sizeof_long(regs); /* Pop incorrect return address */
- if (emulate_push_stack(regs, utask->vaddr + auprobe->defparam.ilen))
+ if (emulate_push_stack(regs, retaddr))
return -ERESTART;
+ err = shstk_update_last_frame(retaddr);
+ if (err)
+ return err;
}
/* popf; tell the caller to not touch TF */
if (auprobe->defparam.fixups & UPROBE_FIX_SETF)
@@ -1338,6 +1344,10 @@ static bool branch_emulate_op(struct arch_uprobe *auprobe, struct pt_regs *regs)
*/
if (emulate_push_stack(regs, new_ip))
return false;
+ if (shstk_push(new_ip) == -EFAULT) {
+ regs->sp += sizeof_long(regs);
+ return false;
+ }
} else if (!check_jmp_cond(auprobe, regs)) {
offs = 0;
}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 954c36e28101..d7f3e2c2ecb1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4729,7 +4729,7 @@ static void perf_remove_from_owner(struct perf_event *event);
static void perf_event_exit_event(struct perf_event *event,
struct perf_event_context *ctx,
struct task_struct *task,
- bool revoke);
+ unsigned long detach_flags);
/*
* Removes all events from the current task that have been marked
@@ -4756,7 +4756,7 @@ static void perf_event_remove_on_exec(struct perf_event_context *ctx)
modified = true;
- perf_event_exit_event(event, ctx, ctx->task, false);
+ perf_event_exit_event(event, ctx, ctx->task, DETACH_GROUP);
}
raw_spin_lock_irqsave(&ctx->lock, flags);
@@ -12937,7 +12937,7 @@ static void __pmu_detach_event(struct pmu *pmu, struct perf_event *event,
/*
* De-schedule the event and mark it REVOKED.
*/
- perf_event_exit_event(event, ctx, ctx->task, true);
+ perf_event_exit_event(event, ctx, ctx->task, DETACH_REVOKE);
/*
* All _free_event() bits that rely on event->pmu:
@@ -14525,12 +14525,13 @@ static void
perf_event_exit_event(struct perf_event *event,
struct perf_event_context *ctx,
struct task_struct *task,
- bool revoke)
+ unsigned long detach_flags)
{
struct perf_event *parent_event = event->parent;
- unsigned long detach_flags = DETACH_EXIT;
unsigned int attach_state;
+ detach_flags |= DETACH_EXIT;
+
if (parent_event) {
/*
* Do not destroy the 'original' grouping; because of the
@@ -14553,8 +14554,8 @@ perf_event_exit_event(struct perf_event *event,
sync_child_event(event, task);
}
- if (revoke)
- detach_flags |= DETACH_GROUP | DETACH_REVOKE;
+ if (detach_flags & DETACH_REVOKE)
+ detach_flags |= DETACH_GROUP;
perf_remove_from_context(event, detach_flags);
/*
@@ -14642,7 +14643,7 @@ static void perf_event_exit_task_context(struct task_struct *task, bool exit)
perf_event_task(task, ctx, 0);
list_for_each_entry_safe(child_event, next, &ctx->event_list, event_entry)
- perf_event_exit_event(child_event, ctx, exit ? task : NULL, false);
+ perf_event_exit_event(child_event, ctx, exit ? task : NULL, 0);
mutex_unlock(&ctx->mutex);
diff --git a/tools/testing/selftests/x86/test_shadow_stack.c b/tools/testing/selftests/x86/test_shadow_stack.c
index 21af54d5f4ea..3d6ca33edba4 100644
--- a/tools/testing/selftests/x86/test_shadow_stack.c
+++ b/tools/testing/selftests/x86/test_shadow_stack.c
@@ -873,6 +873,86 @@ out:
return err;
}
+/* Keep the CALL first so the function address is exactly the probed CALL. */
+extern void uprobe_call_trigger(void);
+asm (".pushsection .text\n"
+ ".global uprobe_call_target\n"
+ ".type uprobe_call_target, @function\n"
+ "uprobe_call_target:\n"
+ " ret\n"
+ ".size uprobe_call_target, .-uprobe_call_target\n"
+
+ ".global uprobe_call_trigger\n"
+ ".type uprobe_call_trigger, @function\n"
+ "uprobe_call_trigger:\n"
+ " call uprobe_call_target\n"
+ " ret\n"
+ ".size uprobe_call_trigger, .-uprobe_call_trigger\n"
+ ".popsection\n"
+);
+
+/* If CALL emulation misses the shadow stack update, this exits via SIGSEGV. */
+static int test_uprobe_call(void)
+{
+ const size_t attr_sz = sizeof(struct perf_event_attr);
+ const char *file = "/proc/self/exe";
+ int fd = -1, type, err = 1;
+ struct perf_event_attr attr;
+ struct sigaction sa = {};
+ ssize_t offset;
+
+ type = determine_uprobe_perf_type();
+ if (type < 0) {
+ if (type == -ENOENT)
+ printf("[SKIP]\tUprobe on CALL test, uprobes are not available\n");
+ return 0;
+ }
+
+ offset = get_uprobe_offset(uprobe_call_trigger);
+ if (offset < 0)
+ return 1;
+
+ sa.sa_sigaction = segv_gp_handler;
+ sa.sa_flags = SA_SIGINFO;
+ if (sigaction(SIGSEGV, &sa, NULL))
+ return 1;
+
+ /* Setup entry uprobe through perf event interface. */
+ memset(&attr, 0, attr_sz);
+ attr.size = attr_sz;
+ attr.type = type;
+ attr.config = 0;
+ attr.config1 = (__u64)(unsigned long)file;
+ attr.config2 = offset;
+
+ fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */, -1 /* cpu */,
+ -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
+ if (fd < 0)
+ goto out;
+
+ if (sigsetjmp(jmp_buffer, 1))
+ goto out;
+
+ if (ARCH_PRCTL(ARCH_SHSTK_ENABLE, ARCH_SHSTK_SHSTK))
+ goto out;
+
+ /*
+ * This either segfaults and goes through sigsetjmp above
+ * or succeeds and we're good.
+ */
+ uprobe_call_trigger();
+
+ printf("[OK]\tUprobe on CALL test\n");
+ err = 0;
+
+out:
+ ARCH_PRCTL(ARCH_SHSTK_DISABLE, ARCH_SHSTK_SHSTK);
+ signal(SIGSEGV, SIG_DFL);
+ if (fd >= 0)
+ close(fd);
+ return err;
+}
+
void segv_handler_ptrace(int signum, siginfo_t *si, void *uc)
{
/* The SSP adjustment caused a segfault. */
@@ -1071,6 +1151,12 @@ int main(int argc, char *argv[])
goto out;
}
+ if (test_uprobe_call()) {
+ ret = 1;
+ printf("[FAIL]\tuprobe on CALL test\n");
+ goto out;
+ }
+
return ret;
out: