On Fri, Nov 29, 2024 at 4:59 PM Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx> wrote: > Lightweight guard region support has been added to Linux 6.13, which adds > MADV_GUARD_INSTALL and MADV_GUARD_REMOVE flags to the madvise() system > call. Therefore, update the manpage for madvise() and describe these > operations. [...] > +.TP > +.BR MADV_GUARD_INSTALL " (since Linux 6.13)" > +Install a lightweight guard region into the range specified by > +.I addr > +and > +.IR size , > +causing any read or write in the range to result in a fatal > +.B SIGSEGV > +signal being raised. Single-word nitpick: Maybe remove the word "fatal"? I think the term "fatal signal" normally refers to a signal that is guaranteed to terminate the task (that's how the signal handling code uses the term, more or less); but a SIGSEGV caused by VM_FAULT_SIGSEGV can AFAIK be handled by a userspace signal handler. SIGKILL is the one signal that is always fatal; the kernel can also send other signals in an always-fatal way, like with force_fatal_sig() or force_exit_sig(), but those are not used for VM_FAULT_SIGSEGV. (Those functions are mostly for cases where we can't continue because something is in an unsafe state, like if a signal return failed and the register state might now be messed up.)
