lookup_prev_stack_frame(9)

💖 lookup_prev_stack_frame(9) 💖

okay so bestie, welcome to the lookup_prev_stack_frame(9) page from the Kernel API Manual — this is the microblaze stack-unwinding lore and ngl it's kind of iconic once you get it. it's literally a little detective that goes "who called you, bestie? 👀" and hands you back the previous function's frame. let's get into it 🫶

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✨ NAME ✨

lookup_prev_stack_frame — find the stack frame of the previous function. that's it, that's the vibe ✨

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🎀 SYNOPSIS 🎀

int lookup_prev_stack_frame (unsigned long fp , unsigned long pc ,
unsigned long leaf_return , unsigned long *pprev_fp , unsigned long
*pprev_pc );

copy it exactly like that, no cap 🧚

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🌸 ARGUMENTS 🌸

• fp — the frame (stack) pointer for the current function 💅
• pc — the program counter, chillin' inside the current function
• leaf_return — the r15 value within the current function. and here's the tea: if the current function is a leaf, this is the caller's return address 👑
• pprev_fp — on exit, this gets set to the frame (stack) pointer for the previous function 🦋
• pprev_pc — on exit, this gets set to the current function's caller's return address ⭐

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🔥 DESCRIPTION 🔥

okay so the return value is giving very simple, very demure:

• 0 on success — slay 💖
• -EINVAL if the previous frame cannot be found — like, it's just not there bestie, and that's a -EINVAL 😭

that's the whole description, no extra plot twists, periodt.

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🌈 SEE ALSO 🌈

go check these out, iykyk 👑

• Kernel file ./arch/microblaze/kernel/unwind.c
• get_frame_size(9)
• find_frame_creation(9)
• unwind_trap(9)
• microblaze_unwind_inner(9)
• microblaze_unwind(9)

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and that's the whole page, bestie 🎀✨

this little masterpiece lives in ./arch/microblaze/kernel and the date on it is October 2026 — so yeah, mark your calendar and stan the unwinder 💜💅🦋