Allow programs to realloc their accounts within limits

program-runtime/src/instruction_processor.rs

@@ -11,7 +11,7 @@ use solana_sdk::{
     process_instruction::{Executor, InvokeContext, Logger, ProcessInstructionWithContext},
     pubkey::Pubkey,
     rent::Rent,
-    system_program,
+    system_instruction::MAX_PERMITTED_DATA_LENGTH,
 };
 use std::{
     cell::{Ref, RefCell},
@@ -151,13 +151,14 @@ impl PreAccount {
             }
         }
 
-        // Only the system program can change the size of the data
-        //  and only if the system program owns the account
+        // Account data size cannot exceed a maxumum length
+        if post.data().len() > MAX_PERMITTED_DATA_LENGTH as usize {
+            return Err(InstructionError::InvalidRealloc);
+        }
+
+        // The owner of the account can change the size of the data
         let data_len_changed = pre.data().len() != post.data().len();
-        if data_len_changed
-            && (!system_program::check_id(program_id) // line coverage used to get branch coverage
-                || !system_program::check_id(pre.owner()))
-        {
+        if data_len_changed && program_id != pre.owner() {
             return Err(InstructionError::AccountDataSizeChanged);
         }
 
@@ -774,7 +775,7 @@ impl InstructionProcessor {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use solana_sdk::{account::Account, instruction::InstructionError};
+    use solana_sdk::{account::Account, instruction::InstructionError, system_program};
 
     #[test]
     fn test_is_zeroed() {
@@ -1171,11 +1172,18 @@ mod tests {
             "system program should not be able to change another program's account data size"
         );
         assert_eq!(
-            Change::new(&alice_program_id, &alice_program_id)
+            Change::new(&alice_program_id, &solana_sdk::pubkey::new_rand())
                 .data(vec![0], vec![0, 0])
                 .verify(),
             Err(InstructionError::AccountDataSizeChanged),
-            "non-system programs cannot change their data size"
+            "one program should not be able to change another program's account data size"
+        );
+        assert_eq!(
+            Change::new(&alice_program_id, &alice_program_id)
+                .data(vec![0], vec![0, 0])
+                .verify(),
+            Ok(()),
+            "programs can change their own data size"
         );
         assert_eq!(
             Change::new(&system_program::id(), &system_program::id())
@@ -1197,7 +1205,7 @@ mod tests {
                 .executable(false, true)
                 .verify(),
             Err(InstructionError::ExecutableModified),
-            "Program should not be able to change owner and executable at the same time"
+            "program should not be able to change owner and executable at the same time"
         );
     }
 

programs/bpf/Cargo.toml

@@ -26,7 +26,9 @@ itertools = "0.10.1"
 log = "0.4.11"
 miow = "0.3.6"
 net2 = "0.2.37"
-solana-bpf-loader-program = { path = "../bpf_loader", version = "=1.8.0" }
+solana-bpf-loader-program = { path = "../bpf_loader", version = "=1.8.0"}
+solana-bpf-rust-realloc = { path = "rust/realloc", version = "=1.8.0", features = ["custom-heap"]}
+solana-bpf-rust-realloc-invoke = { path = "rust/realloc_invoke", version = "=1.8.0", features = ["custom-heap"]}
 solana-cli-output = { path = "../../cli-output", version = "=1.8.0" }
 solana-logger = { path = "../../logger", version = "=1.8.0" }
 solana-measure = { path = "../../measure", version = "=1.8.0" }
@@ -36,7 +38,6 @@ solana-sdk = { path = "../../sdk", version = "=1.8.0" }
 solana-transaction-status = { path = "../../transaction-status", version = "=1.8.0" }
 solana-account-decoder = { path = "../../account-decoder", version = "=1.8.0" }
 
-
 [[bench]]
 name = "bpf_loader"
 
@@ -70,6 +71,8 @@ members = [
     "rust/param_passing",
     "rust/param_passing_dep",
     "rust/rand",
+    "rust/realloc",
+    "rust/realloc_invoke",
     "rust/ro_modify",
     "rust/ro_account_modify",
     "rust/sanity",

programs/bpf/build.rs

@@ -83,6 +83,8 @@ fn main() {
             "panic",
             "param_passing",
             "rand",
+            "realloc",
+            "realloc_invoke",
             "ro_modify",
             "ro_account_modify",
             "sanity",

programs/bpf/rust/realloc/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "solana-bpf-rust-realloc"
+version = "1.8.0"
+description = "Solana BPF test program written in Rust"
+authors = ["Solana Maintainers <[email protected]>"]
+repository = "https://github.com/solana-labs/solana"
+license = "Apache-2.0"
+homepage = "https://solana.com/"
+documentation = "https://docs.rs/solana-bpf-rust-realloc"
+edition = "2018"
+
+[features]
+custom-heap = []
+
+[dependencies]
+solana-program = { path = "../../../../sdk/program", version = "=1.8.0" }
+
+[lib]
+crate-type = ["lib", "cdylib"]
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

programs/bpf/rust/realloc/src/instructions.rs

@@ -0,0 +1,10 @@
+//! @brief Example Rust-based BPF realloc test program
+
+pub const REALLOC_ZERO: u8 = 0;
+pub const REALLOC_TO: u8 = 1;
+pub const REALLOC_MAX_PLUS_ONE: u8 = 2;
+pub const REALLOC_MAX: u8 = 3;
+pub const REALLOC_AND_ASSIGN: u8 = 4;
+pub const REALLOC_AND_ASSIGN_TO_SELF: u8 = 5;
+pub const ASSIGN_TO_SELF_AND_REALLOC: u8 = 6;
+pub const CHECK: u8 = 7;

programs/bpf/rust/realloc/src/lib.rs

@@ -0,0 +1,91 @@
+//! @brief Example Rust-based BPF realloc test program
+
+pub mod instructions;
+
+extern crate solana_program;
+use crate::instructions::*;
+use solana_program::{
+    account_info::AccountInfo, entrypoint, entrypoint::ProgramResult,
+    entrypoint::MAX_PERMITTED_DATA_INCREASE, msg, program::invoke, pubkey::Pubkey,
+    system_instruction, system_program,
+};
+use std::convert::TryInto;
+
+entrypoint!(process_instruction);
+#[allow(clippy::unnecessary_wraps)]
+fn process_instruction(
+    program_id: &Pubkey,
+    accounts: &[AccountInfo],
+    instruction_data: &[u8],
+) -> ProgramResult {
+    let account = &accounts[0];
+    let pre_len = account.data_len();
+
+    match instruction_data[0] {
+        REALLOC_ZERO => {
+            msg!("realloc to zero");
+            account.realloc(0)?;
+            assert_eq!(0, account.data_len());
+        }
+        REALLOC_TO => {
+            let (bytes, _) = instruction_data[2..].split_at(std::mem::size_of::<usize>());
+            let new_len = usize::from_le_bytes(bytes.try_into().unwrap());
+            msg!("realloc to {}", new_len);
+            account.realloc(new_len)?;
+            assert_eq!(new_len, account.data_len());
+        }
+        REALLOC_MAX_PLUS_ONE => {
+            msg!("realloc to max + 1");
+            account.realloc(pre_len + MAX_PERMITTED_DATA_INCREASE + 1)?;
+        }
+        REALLOC_MAX => {
+            msg!("realloc to max");
+            account.realloc(pre_len + MAX_PERMITTED_DATA_INCREASE)?;
+            assert_eq!(pre_len + MAX_PERMITTED_DATA_INCREASE, account.data_len());
+            account.try_borrow_mut_data()?[pre_len..].fill(instruction_data[1]);
+        }
+        REALLOC_AND_ASSIGN => {
+            msg!("realloc and assign");
+            account.realloc(pre_len + MAX_PERMITTED_DATA_INCREASE)?;
+            assert_eq!(pre_len + MAX_PERMITTED_DATA_INCREASE, account.data_len());
+            account.assign(&system_program::id());
+            assert_eq!(*account.owner, system_program::id());
+        }
+        REALLOC_AND_ASSIGN_TO_SELF => {
+            msg!("realloc and assign to self via cpi");
+            account.realloc(pre_len + MAX_PERMITTED_DATA_INCREASE)?;
+            assert_eq!(pre_len + MAX_PERMITTED_DATA_INCREASE, account.data_len());
+            invoke(
+                &system_instruction::assign(account.key, program_id),
+                accounts,
+            )?;
+            assert_eq!(pre_len + MAX_PERMITTED_DATA_INCREASE, account.data_len());
+        }
+        ASSIGN_TO_SELF_AND_REALLOC => {
+            msg!("assign to self via cpi and realloc");
+            invoke(
+                &system_instruction::assign(account.key, program_id),
+                accounts,
+            )?;
+            account.realloc(pre_len + MAX_PERMITTED_DATA_INCREASE)?;
+            assert_eq!(pre_len + MAX_PERMITTED_DATA_INCREASE, account.data_len());
+            assert_eq!(account.owner, program_id);
+        }
+        CHECK => {
+            msg!("check");
+            let (bytes, _) = instruction_data[2..].split_at(std::mem::size_of::<usize>());
+            let new_len = usize::from_le_bytes(bytes.try_into().unwrap());
+            assert_eq!(new_len, account.data_len());
+            let data = account.try_borrow_mut_data()?;
+            for x in data[0..5].iter() {
+                assert_eq!(0, *x);
+            }
+            for x in data[5..].iter() {
+                assert_eq!(instruction_data[1], *x);
+            }
+        }
+        _ => panic!(),
+    }
+
+    Ok(())
+}

programs/bpf/rust/realloc_invoke/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "solana-bpf-rust-realloc-invoke"
+version = "1.8.0"
+description = "Solana BPF test program written in Rust"
+authors = ["Solana Maintainers <[email protected]>"]
+repository = "https://github.com/solana-labs/solana"
+license = "Apache-2.0"
+homepage = "https://solana.com/"
+documentation = "https://docs.rs/solana-bpf-rust-realloc-invoke"
+edition = "2018"
+
+[features]
+custom-heap = []
+
+[dependencies]
+solana-program = { path = "../../../../sdk/program", version = "=1.8.0" }
+solana-bpf-rust-realloc = { path = "../realloc", version = "=1.8.0", features = ["custom-heap"]}
+
+[lib]
+crate-type = ["lib", "cdylib"]
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

programs/bpf/rust/realloc_invoke/src/instructions.rs

@@ -0,0 +1,14 @@
+//! @brief Example Rust-based BPF realloc test program
+
+pub const INVOKE_REALLOC_ZERO_RO: u8 = 0;
+pub const INVOKE_REALLOC_ZERO: u8 = 1;
+pub const INVOKE_REALLOC_MAX_PLUS_ONE: u8 = 2;
+pub const INVOKE_REALLOC_MAX: u8 = 3;
+pub const INVOKE_REALLOC_AND_ASSIGN: u8 = 4;
+pub const INVOKE_REALLOC_AND_ASSIGN_TO_SELF: u8 = 5;
+pub const INVOKE_ASSIGN_TO_SELF_AND_REALLOC: u8 = 6;
+pub const INVOKE_REALLOC_INVOKE_CHECK: u8 = 7;
+pub const INVOKE_OVERFLOW: u8 = 8;
+pub const INVOKE_REALLOC_TO: u8 = 9;
+pub const INVOKE_REALLOC_RECURSIVE: u8 = 10;
+pub const INVOKE_CREATE_ACCOUNT_CHECK: u8 = 11;