kcsan_nestable_atomic_begin(9)

💅 kcsan_nestable_atomic_begin(9) 💅

okay bestie, welcome to the Kernel API Manual ✨ this one's a tiny little function that lives in the kernel headers and honestly? iconic.

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🌸 NAME 🌸

kcsan_nestable_atomic_begin — begins a nestable atomic region 🫶

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✨ SYNOPSIS ✨

void kcsan_nestable_atomic_begin (void );

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🎀 ARGUMENTS 🎀

• void — literally no arguments, bestie. nothing. zero. she takes nothing and she gives everything 💅

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🔥 DESCRIPTION 🔥

okay so the whole vibe here is: accesses inside this atomic region may appear to race with other accesses — like, from the outside it looks messy 👀 — but they should be considered atomic. no cap. so don't @ her about the apparent racy behaviour, that's just how she is 🦋

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🦋 SEE ALSO 🦋

she runs with a whole squad, and they're all in the kernel file ./include/linux/kcsan-checks.h:

• __kcsan_check_access(9)
• __kcsan_mb(9)
• __kcsan_wmb(9)
• __kcsan_rmb(9)
• __kcsan_release(9)
• kcsan_disable_current(9)
• kcsan_enable_current(9)
• kcsan_nestable_atomic_end(9)
• kcsan_flat_atomic_begin(9)
• kcsan_flat_atomic_end(9)
• kcsan_atomic_next(9)
• kcsan_set_access_mask(9)
• kcsan_begin_scoped_access(9)
• kcsan_end_scoped_access(9)
• __kcsan_check_read(9)
• __kcsan_check_write(9)
• __kcsan_check_read_write(9)
• kcsan_check_read(9)
• kcsan_check_write(9)
• kcsan_check_read_write(9)
• ASSERT_EXCLUSIVE_WRITER(9)
• ASSERT_EXCLUSIVE_WRITER_SCOPED(9)
• ASSERT_EXCLUSIVE_ACCESS(9)
• ASSERT_EXCLUSIVE_ACCESS_SCOPED(9)
• ASSERT_EXCLUSIVE_BITS(9)

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open the whole crew, you'll never catch her lacking 💖

and that's the tea, bestie 🍓 this little page lives under ./include/linux and it's dated October 2026 — courtesy of the Kernel API Manual herself, signed, sealed, slayed 👑💅