From 8f1134366489055ac294a3d77b8eb84ff950c055 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexander=20Mei=C3=9Fner?= <AlexanderMeissner@gmx.net>
Date: Tue, 21 Dec 2021 12:53:22 +0100
Subject: [PATCH] Fix #21986 (#22035)

* Partial revert "Updates documentation around what needs to be passed in CPI. (#21633)"

* Enforces the program_id being passed explicitly by removing it from get_instruction_keyed_accounts().

* instruction_accounts => instructions_account

(cherry picked from commit ba8e15848e5b7d52cce133e541e92c5aec361a6a)

# Conflicts:
#	program-runtime/src/invoke_context.rs
---
 program-runtime/src/invoke_context.rs         | 24 ++++++++++++-------
 .../rust/instruction_introspection/src/lib.rs | 14 +++++------
 programs/bpf/tests/programs.rs                |  5 +++-
 3 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/program-runtime/src/invoke_context.rs b/program-runtime/src/invoke_context.rs
index 1da706a70f0059..a8113d2e765c88 100644
--- a/program-runtime/src/invoke_context.rs
+++ b/program-runtime/src/invoke_context.rs
@@ -724,9 +724,15 @@ impl<'a> InvokeContext<'a> {
 
     /// Get the owner of the currently executing program
     pub fn get_loader(&self) -> Result<Pubkey, InstructionError> {
-        self.get_instruction_keyed_accounts()
-            .and_then(|keyed_accounts| keyed_accounts.first().ok_or(InstructionError::CallDepth))
-            .and_then(|keyed_account| keyed_account.owner())
+        let frame = self
+            .invoke_stack
+            .last()
+            .ok_or(InstructionError::CallDepth)?;
+        let first_instruction_account = frame
+            .number_of_program_accounts
+            .checked_sub(1)
+            .ok_or(InstructionError::CallDepth)?;
+        frame.keyed_accounts[first_instruction_account].owner()
     }
 
     /// Removes the first keyed account
@@ -754,17 +760,19 @@ impl<'a> InvokeContext<'a> {
             .ok_or(InstructionError::CallDepth)
     }
 
+<<<<<<< HEAD
     /// Get the list of keyed accounts skipping `first_instruction_account` many entries
+=======
+    /// Get the list of keyed accounts without the chain of program accounts
+    ///
+    /// Note: This only contains the `KeyedAccount`s passed by the caller.
+>>>>>>> ba8e15848 (Fix #21986 (#22035))
     pub fn get_instruction_keyed_accounts(&self) -> Result<&[KeyedAccount], InstructionError> {
         let frame = self
             .invoke_stack
             .last()
             .ok_or(InstructionError::CallDepth)?;
-        let first_instruction_account = frame
-            .number_of_program_accounts
-            .checked_sub(1)
-            .ok_or(InstructionError::CallDepth)?;
-        Ok(&frame.keyed_accounts[first_instruction_account..])
+        Ok(&frame.keyed_accounts[frame.number_of_program_accounts..])
     }
 
     /// Get this invocation's LogCollector
diff --git a/programs/bpf/rust/instruction_introspection/src/lib.rs b/programs/bpf/rust/instruction_introspection/src/lib.rs
index f39c811f42057f..726ff265f872bb 100644
--- a/programs/bpf/rust/instruction_introspection/src/lib.rs
+++ b/programs/bpf/rust/instruction_introspection/src/lib.rs
@@ -2,7 +2,6 @@
 
 extern crate solana_program;
 use solana_program::{
-    account_info::next_account_info,
     account_info::AccountInfo,
     entrypoint,
     entrypoint::ProgramResult,
@@ -25,20 +24,19 @@ fn process_instruction(
     }
 
     let secp_instruction_index = instruction_data[0];
-    let account_info_iter = &mut accounts.iter();
-    let instruction_accounts = next_account_info(account_info_iter)?;
-    assert_eq!(*instruction_accounts.key, instructions::id());
-    let data_len = instruction_accounts.try_borrow_data()?.len();
+    let instructions_account = accounts.last().ok_or(ProgramError::NotEnoughAccountKeys)?;
+    assert_eq!(*instructions_account.key, instructions::id());
+    let data_len = instructions_account.try_borrow_data()?.len();
     if data_len < 2 {
         return Err(ProgramError::InvalidAccountData);
     }
 
     let instruction = instructions::load_instruction_at_checked(
         secp_instruction_index as usize,
-        instruction_accounts,
+        instructions_account,
     )?;
 
-    let current_instruction = instructions::load_current_index_checked(instruction_accounts)?;
+    let current_instruction = instructions::load_current_index_checked(instructions_account)?;
     let my_index = instruction_data[1] as u16;
     assert_eq!(current_instruction, my_index);
 
@@ -56,7 +54,7 @@ fn process_instruction(
                 &[instruction_data[0], instruction_data[1], 1],
                 vec![AccountMeta::new_readonly(instructions::id(), false)],
             ),
-            &[instruction_accounts.clone()],
+            accounts,
         )?;
     }
 
diff --git a/programs/bpf/tests/programs.rs b/programs/bpf/tests/programs.rs
index 0c0021bd051e03..7a41fec56cd976 100644
--- a/programs/bpf/tests/programs.rs
+++ b/programs/bpf/tests/programs.rs
@@ -1449,7 +1449,10 @@ fn test_program_bpf_instruction_introspection() {
     );
 
     // Passing transaction
-    let account_metas = vec![AccountMeta::new_readonly(sysvar::instructions::id(), false)];
+    let account_metas = vec![
+        AccountMeta::new(program_id, false),
+        AccountMeta::new(sysvar::instructions::id(), false),
+    ];
     let instruction0 = Instruction::new_with_bytes(program_id, &[0u8, 0u8], account_metas.clone());
     let instruction1 = Instruction::new_with_bytes(program_id, &[0u8, 1u8], account_metas.clone());
     let instruction2 = Instruction::new_with_bytes(program_id, &[0u8, 2u8], account_metas);