[PATCH] man/man2const/F_{ADD,GET}_SEALS.2const: document F_SEAL_EXEC

[Pratyush Yadav <pratyush@kernel.org>]

From: "Pratyush Yadav (Google)" <pratyush@kernel.org>

F_SEAL_EXEC was added in Linux v6.3. It seals the exec bits of the
memfd. Document it.

Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
---

Notes:
    I discovered this was missing when working on [0]. I had to look at the
    code to figure out how it was supposed to behave.
    
    Disclaimer: I used help from Gemini to write this patch, mainly because
    I don't know the man page syntax. If the man-pages project also uses the
    AI-assisted tags as Linux, feel free to add:
    
    Assisted-by: Gemini:gemini-3.1-pro
    
    [0] https://lore.kernel.org/linux-mm/20260505133922.797635-1-pratyush@kernel.org/

 man/man2const/F_GET_SEALS.2const | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/man/man2const/F_GET_SEALS.2const b/man/man2const/F_GET_SEALS.2const
index 175025c10..2de8009a8 100644
--- a/man/man2const/F_GET_SEALS.2const
+++ b/man/man2const/F_GET_SEALS.2const
@@ -176,6 +176,25 @@ will fail with
 Using this seal,
 one process can create a memory buffer that it can continue to modify
 while sharing that buffer on a "read-only" basis with other processes.
+.TP
+.BR F_SEAL_EXEC " (since Linux 6.3)"
+If this seal is set, the execute bits in the file mode cannot be modified.
+Any attempt to modify these bits via
+.BR chmod (2),
+.BR fchmod (2),
+or similar calls will fail with
+.BR EPERM .
+This preserves the execute bits as they were at the time of sealing,
+making the file either permanently executable or permanently unexecutable.
+.IP
+If this seal is applied to a file that is already executable,
+the kernel also implicitly applies
+.BR F_SEAL_SHRINK ,
+.BR F_SEAL_GROW ,
+.BR F_SEAL_WRITE ,
+and
+.BR F_SEAL_FUTURE_WRITE ,
+preventing any further modifications to the contents of the file.
 .SH RETURN VALUE
 .TP
 .B F_GET_SEALS

base-commit: 9db8ca91f920b9aba40ed68de6b8da0ca9dbefaa
-- 
2.54.0.1013.g208068f2d8-goog