vma_assert_stabilised(9)

NAME 💅

vma_assert_stabilised — bestie, this is the assertion that says your VMA can’t just get changed out from underneath you, whether that’s because a VMA lock or an mmap lock is being held. No cap.

This is from the Kernel API Manual, and the star of the show is literally vma_assert_stabilised(9).

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SYNOPSIS ✨

void vma_assert_stabilised (struct vm_area_struct *vma );

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ARGUMENTS 🎀

• vma — the VMA whose stability we want to assess. That’s the whole vibe check right there.

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DESCRIPTION 🦋

Okay so, if lockdep is enabled, we can precisely ensure stability via either an mmap lock owned by us or a specific VMA lock. Slay. That’s the precise, locked-down scenario.

With lockdep disabled, though? We may sometimes race with other threads acquiring the mmap read lock at the same time as our VMA read lock. So yeah, that’s the little caveat, and it’s giving “we’re not fully protected in this mode” energy. Not me pretending that race doesn’t exist — it’s right there. 🙈

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SEE ALSO 🌸

• Kernel file ./include/linux/mmap_lock.h
• vma_refcount_put(9)
• vma_start_write_killable(9)
• vma_assert_write_locked(9)
• vma_assert_locked(9)

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Go check the kernel file and those related functions if you want the full lore. Iykyk. 💜

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Later, bestie — this page is from ./include/linux, dated October 2026, and it’s serving Kernel API Manual realness. Periodt. 👑💖