vmw_find_first_diff(9)

💅 vmw_find_first_diff — find the first difference between dst and src

okay so bestie, welcome to the Kernel API Manual 🫶 — yes, that Kernel API Manual, the one that lives in vmw_find_first_diff(9). today's main character is a little function that literally just tells you where two blobs of memory stop matching. it's giving "spot the difference" but make it kernel. 🔥

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✨ SYNOPSIS ✨

size_t vmw_find_first_diff (const u8 *dst , const u8 *src , size_t size
, size_t granularity );

that's it. that's the whole vibe check. four args, one size_t back out. no cap. 💅

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🌸 ARGUMENTS 🌸

• dst — the destination address 💖 like, the place we're comparing to, bestie.
• src — the source address ✨ the other one in the comparison. the original. the blueprint.
• size — number of bytes to compare 🎀 so how much of this we're actually staring at.
• granularity — the granularity needed for the return value in bytes 🦋 iykyk — it's the unit the answer comes back in.

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👑 RETURN 👑

the offset from find start where the first difference was encountered, in bytes ⭐ like, "hey bestie, they stopped matching right here."

and if no difference was found? the function returns a value >= size 💀 yep, greater than or equal to size — that's your signal that everything matched, no notes, periodt.

ngl, that's the whole trick: a real hit is always < size, and "nothing to report" is >= size. so don't go treating a "no diff" return like an actual index, okay? 🙈

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/vmwgfx/vmwgfx_blit.c 📁
• vmw_find_last_diff(9)
• vmw_memcpy(9)
• vmw_adjust_rect(9)
• vmw_diff_memcpy(9)
• struct vmw_bo_blit_line_data(9)
• vmw_bo_cpu_blit_line(9)
• vmw_bo_cpu_blit(9)

the whole friend group fr fr 🧚 go read their pages too, they're iconic.

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mwah 💜 that's a wrap! this little beauty comes to you from ./drivers/gpu/drm/vmwgfx, dated October 2026, and it goes by vmw_find_first_diff(9) — same as always, no rebranding, slay. 🎀✨