# Fact Check Report

## Verified

- **SHA `c51f878379b1`**: resolves; subject "mac80211_hwsim: fix beacon timing" matches report verbatim ✓
- **SHA `e57f8a489c29`**: resolves; subject "wifi: mac80211_hwsim: send a beacon per link" matches report verbatim ✓
- **SHA `254f49634ee1`** (HEAD/PATCH_BASE): resolves; subject "Linux 7.1-rc1" matches report ✓
- **File paths** (all present in tree at `254f49634ee1`):
  - `drivers/net/wireless/virtual/mac80211_hwsim.c` ✓
  - `net/mac80211/driver-ops.c` ✓
  - `net/mac80211/offchannel.c` ✓
  - `net/mac80211/scan.c` ✓
  - `net/wireless/core.c` ✓
  - `kernel/workqueue.c` ✓
  - `kernel/kthread.c` ✓
  - `arch/x86/kernel/process.c` ✓
  - `arch/x86/entry/entry_64.S` ✓
- **`mac80211_hwsim_link_info_changed` block** (lines 2701–2739, 2779): code content verified against tree ✓
- **`mac80211_hwsim_link_data` struct** (lines 660–664): content verified ✓
- **`drv_link_info_changed` block** (lines 460–501): content verified ✓
- **`ieee80211_offchannel_return` block** (lines 133–169): content verified; crash/call site at line 160 correct ✓
- **`__ieee80211_scan_completed` block** (lines 516–520): content verified ✓
- **`mac80211_hwsim_config` comparison block** (lines 2630–2635): content verified ✓
- **Register values** (RCX=0, RSI=0, RAX=R12=`0x000650757bb12572`): consistent between CPU Registers table and analysis body ✓
- **RBX=`0x200`**: consistent with `BSS_CHANGED_BEACON_ENABLED = 1<<9 = 0x200` ✓

## Whitespace / cosmetic fixes applied

- **Marker normalisation (report.md)**: 5 markers converted from `→NNN<code>` to `→ NNN <code>` format:
  - Line 110: `→2734until_tbtt` → `→ 2734 \t\t\tuntil_tbtt`
  - Line 176: `→497else if` → `→ 497 \telse if`
  - Line 197: `→160ieee80211_link_info_change_notify` → `→ 160 \t\tieee80211_link_info_change_notify`
  - Line 213: `→519ieee80211_offchannel_return` → `→ 519 \t\tieee80211_offchannel_return`
  - Line 298: `→2734 until_tbtt` → `→ 2734 \t\t\tuntil_tbtt`
- **Marker normalisation (analysis-email.txt)**: 4 markers converted from `->NNN<code>` to `-> NNN <code>`:
  - `->2734 until_tbtt` → `-> 2734 \t\t\tuntil_tbtt`
  - `->497 else if` → `-> 497 \telse if`
  - `->156 ieee80211_link_info_change_notify` → `-> 160 \t\tieee80211_link_info_change_notify` (line number corrected too)
  - `->519 ieee80211_offchannel_return` → `-> 519 \t\tieee80211_offchannel_return`
- **Indentation/whitespace (report.md)**: all seven code blocks updated to match tree verbatim (source tab indentation restored; missing space between line-number prefix and code added):
  - `mac80211_hwsim_link_info_changed` block (section 1)
  - `mac80211_hwsim_link_data` struct block
  - `drv_link_info_changed` block
  - `ieee80211_offchannel_return` block
  - `__ieee80211_scan_completed` block
  - `mac80211_hwsim_config` comparison block
  - Analysis "What" duplicate of `mac80211_hwsim_link_info_changed`
- **Line numbers corrected (analysis-email.txt)**: `ieee80211_offchannel_return` block had numbers off by 4 and off by 2 (both within ±10):
  - Lines 153–158 → corrected to 157–162
  - Lines 165–166 → corrected to 163–164
- **No `⛔` checkpoint markers found** in report.md.

## Doubts flagged

*(none)*

## Email discrepancies (analysis-email.txt)

- Line numbers in `ieee80211_offchannel_return` block were off by 4 (153–158 instead of 157–162) and by 2 (165–166 instead of 163–164). Corrected as cosmetic fix (within ±10 rule).

## Not checked

- Sections 6–11 of the backtrace (workqueue, kthread, ret_from_fork, ret_from_fork_asm): only prose descriptions, no checkable code blocks.
- `cfg80211_wiphy_work` (section 5): marked as "source at line 513 calls scan completion work handler" with no code block to verify.
- Disassembly block: not verifiable from source tree (binary-only).
- git blame table: not independently re-run (would exceed git call budget).

## Source of truth used

- Git tree: `/sdb1/arjan/git/oops-skill/oops-workdir/linux` at `254f49634ee1` (v7.1-rc1)
- Key Elements table in report.md
- backtrace.json (present; used for context only, not for code verification per instructions)