From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] kanoj-mm21-2.3.23 alow larger sizes to shmget() References: <199910282204.PAA76687@google.engr.sgi.com> Mime-Version: 1.0 (generated by tm-edit 7.108) Content-Type: text/plain; charset=US-ASCII From: Christoph Rohland Date: 01 Nov 1999 10:41:25 +0100 In-Reply-To: kanoj@google.engr.sgi.com's message of "Thu, 28 Oct 1999 15:04:20 -0700 (PDT)" Message-ID: Sender: owner-linux-mm@kvack.org Return-Path: To: Kanoj Sarcar Cc: torvalds@transmeta.com, linux-mm@kvack.org List-ID: Hi Kanoj, This is probably breaking user space applications since shmid_ds is shared with user space in shmctl(2). On 32bit machines this does not matter, since sizeof(int) == sizeof(size_t), but on 64bit this will break. How do we handle this? Greetings Christoph kanoj@google.engr.sgi.com (Kanoj Sarcar) writes: > Linus, > > Per our previous discussion, this is the patch to change the shmget() > api to permit larger shm segments (now that larger user address spaces, > as well as large memory machines are possible). > > Note that I have defined shmget() as > shmget(key_t, size_t, int) > instead of as > shmget(key_t, unsigned int, int) > or as > shmget(key_t, unsigned long, int). > > This is because the single unix spec sets down the first definition > (http://www.opengroup.org/onlinepubs/007908799/xsh/shmget.html). > This becomes interesting, because size_t is of different sizes on > different architectures, so the shmfs code has to do careful formatting. > (This logic is also probably needed in the ipcs command). > > Let me know if the patch looks okay. > > Thanks. > > Kanoj -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/