Re: [PATCH] sh: remove CONFIG_VSYSCALL reference from UAPI
John Paul Adrian Glaubitz <[email protected]>
| Newsgroups | gmane.linux.ports.sh.devel,gmane.linux.kernel |
|---|---|
| Message-ID | <9dfb01dced05b0efe0dbde22b8470e0b0bbc5b38.camel@physik.fu-berlin.de> |
Hi, On Mon, 2026-01-12 at 12:58 +0100, Thomas Weißschuh wrote: > > Thanks for your patch! > > > > I don't really know what AT_SYSINFO_EHDR is about. Could you explain the background > > a little so that I have a better understanding of what I am reviewing? > > It is the entrypoint to the vDSO. From getauxval(3): > > AT_SYSINFO_EHDR > The address of a page containing the virtual Dynamic Shared Object (vDSO) that the kernel creates > in order to provide fast implementations of certain system calls. > > > That UAPI constant needs to be exposed to userspace even if the specific > kernel does not have a vDSO. This is the current behavior which is preserved. > Userspace will detect the presence or absence of the vDSO based in the > auxiliary vector. Thanks, this explains a lot. I will review the patch later this week. Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer `. `' Physicist `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913