5.4-stable patches

added patches:
	revert-ia64-kprobes-use-generic-kretprobe-trampoline-handler.patch

diff --git a/queue-5.4/revert-ia64-kprobes-use-generic-kretprobe-trampoline-handler.patch b/queue-5.4/revert-ia64-kprobes-use-generic-kretprobe-trampoline-handler.patch
new file mode 100644 (file)
index 0000000..0024350
--- /dev/null
+++ b/queue-5.4/revert-ia64-kprobes-use-generic-kretprobe-trampoline-handler.patch
@@ -0,0 +1,129 @@
+From mhiramat@kernel.org  Mon Jan 24 16:08:19 2022
+From: Masami Hiramatsu <mhiramat@kernel.org>
+Date: Sat, 15 Jan 2022 21:59:16 +0900
+Subject: Revert "ia64: kprobes: Use generic kretprobe trampoline handler"
+To: stable@vger.kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>, Sasha Levin <sashal@kernel.org>
+Message-ID: <164225155571.1964629.11131335649262508943.stgit@devnote2>
+
+From: Masami Hiramatsu <mhiramat@kernel.org>
+
+This reverts commit 77fa5e15c933a1ec812de61ad709c00aa51e96ae.
+
+Since the upstream commit e792ff804f49720ce003b3e4c618b5d996256a18
+depends on the generic kretprobe trampoline handler, which was
+introduced by commit 66ada2ccae4e ("kprobes: Add generic kretprobe
+trampoline handler") but that is not ported to the stable kernel
+because it is not a bugfix series.
+So revert this commit to fix a build error.
+
+NOTE: I keep commit a7fe2378454c ("ia64: kprobes: Fix to pass
+correct trampoline address to the handler") on the tree, that seems
+just a cleanup without the original reverted commit, but it would
+be better to use dereference_function_descriptor() macro instead
+of accessing descriptor's field directly.
+
+Fixes: 77fa5e15c933 ("ia64: kprobes: Use generic kretprobe trampoline handler")
+Reported-by: kernel test robot <lkp@intel.com>
+Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/ia64/kernel/kprobes.c |   78 +++++++++++++++++++++++++++++++++++++++++++--
+ 1 file changed, 75 insertions(+), 3 deletions(-)
+
+--- a/arch/ia64/kernel/kprobes.c
++++ b/arch/ia64/kernel/kprobes.c
+@@ -396,10 +396,83 @@ static void kretprobe_trampoline(void)
+ {
+ }
+ 
++/*
++ * At this point the target function has been tricked into
++ * returning into our trampoline.  Lookup the associated instance
++ * and then:
++ *    - call the handler function
++ *    - cleanup by marking the instance as unused
++ *    - long jump back to the original return address
++ */
+ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+ {
+-      regs->cr_iip = __kretprobe_trampoline_handler(regs,
+-              dereference_function_descriptor(kretprobe_trampoline), NULL);
++      struct kretprobe_instance *ri = NULL;
++      struct hlist_head *head, empty_rp;
++      struct hlist_node *tmp;
++      unsigned long flags, orig_ret_address = 0;
++      unsigned long trampoline_address =
++              (unsigned long)dereference_function_descriptor(kretprobe_trampoline);
++
++      INIT_HLIST_HEAD(&empty_rp);
++      kretprobe_hash_lock(current, &head, &flags);
++
++      /*
++       * It is possible to have multiple instances associated with a given
++       * task either because an multiple functions in the call path
++       * have a return probe installed on them, and/or more than one return
++       * return probe was registered for a target function.
++       *
++       * We can handle this because:
++       *     - instances are always inserted at the head of the list
++       *     - when multiple return probes are registered for the same
++       *       function, the first instance's ret_addr will point to the
++       *       real return address, and all the rest will point to
++       *       kretprobe_trampoline
++       */
++      hlist_for_each_entry_safe(ri, tmp, head, hlist) {
++              if (ri->task != current)
++                      /* another task is sharing our hash bucket */
++                      continue;
++
++              orig_ret_address = (unsigned long)ri->ret_addr;
++              if (orig_ret_address != trampoline_address)
++                      /*
++                       * This is the real return address. Any other
++                       * instances associated with this task are for
++                       * other calls deeper on the call stack
++                       */
++                      break;
++      }
++
++      regs->cr_iip = orig_ret_address;
++
++      hlist_for_each_entry_safe(ri, tmp, head, hlist) {
++              if (ri->task != current)
++                      /* another task is sharing our hash bucket */
++                      continue;
++
++              if (ri->rp && ri->rp->handler)
++                      ri->rp->handler(ri, regs);
++
++              orig_ret_address = (unsigned long)ri->ret_addr;
++              recycle_rp_inst(ri, &empty_rp);
++
++              if (orig_ret_address != trampoline_address)
++                      /*
++                       * This is the real return address. Any other
++                       * instances associated with this task are for
++                       * other calls deeper on the call stack
++                       */
++                      break;
++      }
++      kretprobe_assert(ri, orig_ret_address, trampoline_address);
++
++      kretprobe_hash_unlock(current, &flags);
++
++      hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
++              hlist_del(&ri->hlist);
++              kfree(ri);
++      }
+       /*
+        * By returning a non-zero value, we are telling
+        * kprobe_handler() that we don't want the post_handler
+@@ -412,7 +485,6 @@ void __kprobes arch_prepare_kretprobe(st
+                                     struct pt_regs *regs)
+ {
+       ri->ret_addr = (kprobe_opcode_t *)regs->b0;
+-      ri->fp = NULL;
+ 
+       /* Replace the return addr with trampoline addr */
+       regs->b0 = (unsigned long)dereference_function_descriptor(kretprobe_trampoline);

diff --git a/queue-5.4/series b/queue-5.4/series
index dd3c170190eb2ee4303605f365a5213d5023a91d..57617470447c1b6d94b3c2d6251bfdef6ed82faa 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -318,3 +318,4 @@ scripts-dtc-dtx_diff-remove-broken-example-from-help-text.patch
 lib82596-fix-irq-check-in-sni_82596_probe.patch
 lib-test_meminit-destroy-cache-in-kmem_cache_alloc_bulk-test.patch
 mtd-nand-bbt-fix-corner-case-in-bad-block-table-handling.patch
+revert-ia64-kprobes-use-generic-kretprobe-trampoline-handler.patch