TLSF and the Temple of Corrupted Memory

[DrZlo13]

What's new

• [ Describe changes here ]

Verification

• [ Describe how to verify changes ]

Checklist (For Reviewer)

• [ ] PR has description of feature/bug or link to Confluence/Jira task
• [ ] Description contains actions to verify feature/bugfix
• [ ] I've built this code, uploaded it to the device and verified feature/bugfix

[github-actions[bot]]

Compiled f7 firmware for commit d4b70a6a:

• 📦 Update package
• 📥 DFU file
• ☁️ Web/App updater
• 📊 Size report

[CookiePLMonster]

Regarding the 8-byte alignment, GCC indeed appears to make that assumption, with or without -Os.

This code:

int32_t align_test_app(void* p) {
    UNUSED(p);
    FURI_LOG_I("TEST", "Hello world");
    FURI_LOG_I("TEST", "I'm align_test!");

    void* b = malloc(4);

    uintptr_t valB = (uintptr_t)b;
    return (valB & 7) == 0;
}

compiled into:

So it's a very good idea to guarantee proper alignment, at least for malloc and realloc.

[github-actions[bot]]

PVS-Studio report for commit 7d50f4b5:

• Report

[DrZlo13]

I disabled all dolphin animations and ran some tests:

tlsf

: free Free heap size: 141416 Total heap size: 185560 Minimum heap size: 137696 Maximum heap block: 140328 Aux pool total free: 2752 Aux pool max free block: 2644

: free Free heap size: 141304 Total heap size: 185560 Minimum heap size: 125768 Maximum heap block: 132512 Aux pool total free: 2752 Aux pool max free block: 2644

heap4

: free Free heap size: 146200 Total heap size: 185544 Minimum heap size: 142512 Maximum heap block: 145136 Pool free: 1464 Maximum pool block: 1348

: free Free heap size: 146136 Total heap size: 185544 Minimum heap size: 142440 Maximum heap block: 145296 Pool free: 1464 Maximum pool block: 1348

It looks like in the current version tlsf has no meaning except for the correct implementation of realloc.