This was a wrong assumption. The size of shmid_ds _has_ in fact changed.
I went back to check the alignment of the fields, and it is evident.
>
> Could you please read the thread "2.3.31 - shm broken on Alpha"? The
> current code fails on Alpha, ie we _must_ change it. There _is_ an ABI
> problem. After I changed shmid_ds, the problem was gone.
>
> - as I wrote Chris has prepared a patch for 32-bit uids. This patch adds
> new structures and conversion functions. We will extend that field as
> soon as we add that patch to the standard kernel.
>
Okay.
If you find it useful, here is what I was thinking about. This does
not include preserving the old shmget, which as you point out, we
probably should. This could be changed to use Chris' new code later.
(Code has not even been compiled).
> - I added a new shmget64 because I don't know if we can assume that the
> high bits are always zero. What if an optimizing compiler didn't
> initialize them? Note that the new sysctl is not required for Sparc64:
> the size variable is type size_t, and it's downcasted in
> arch/sparc64/kernel/sys?.c
>
Thanks.
Kanoj
--- arch/alpha/kernel/entry.S Mon Dec 13 15:25:04 1999
+++ arch/alpha/kernel/entry.S Tue Dec 14 14:09:45 1999
@@ -985,7 +985,7 @@
.quad osf_utsname
.quad sys_lchown
.quad osf_shmat
- .quad sys_shmctl /* 210 */
+ .quad sys_shmctlold /* 210 */
.quad sys_shmdt
.quad sys_shmget
.quad alpha_ni_syscall
@@ -1149,3 +1149,4 @@
.quad sys_sendfile /* 370 */
.quad sys_setresgid
.quad sys_getresgid
+ .quad sys_shmctl
--- arch/alpha/kernel/osf_sys.c Mon Dec 13 15:25:04 1999
+++ arch/alpha/kernel/osf_sys.c Tue Dec 14 14:45:25 1999
@@ -31,6 +31,9 @@
#include <linux/shm.h>
#include <linux/poll.h>
#include <linux/file.h>
+#include <linux/types.h>
+#include <linux/ipc.h>
+#include <linux/shm.h>
#include <asm/fpu.h>
#include <asm/io.h>
@@ -38,6 +41,7 @@
#include <asm/system.h>
#include <asm/sysinfo.h>
#include <asm/hwrpb.h>
+#include <asm/processor.h>
extern int do_mount(kdev_t, const char *, const char *, char *, int, void *);
extern int do_pipe(int *);
@@ -1441,4 +1445,104 @@
return -EFAULT;
return ret;
+}
+
+struct shmid_ds_old {
+ struct ipc_perm shm_perm; /* operation perms */
+ int shm_segsz; /* size of segment (bytes) */
+ __kernel_time_t shm_atime; /* last attach time */
+ __kernel_time_t shm_dtime; /* last detach time */
+ __kernel_time_t shm_ctime; /* last change time */
+ __kernel_ipc_pid_t shm_cpid; /* pid of creator */
+ __kernel_ipc_pid_t shm_lpid; /* pid of last operator */
+ unsigned short shm_nattch; /* no. of current attaches */
+ unsigned short shm_unused; /* compatibility */
+ void *shm_unused2; /* ditto - used by DIPC */
+ void *shm_unused3; /* unused */
+};
+
+struct shminfo_old {
+ int shmmax;
+ int shmmin;
+ int shmmni;
+ int shmseg;
+ int shmall;
+}
+
+asmlinkage long sys_shmctlold(int shmid, int cmd, struct shmid_ds_old *buf)
+{
+ struct shmid_ds arg;
+ long ret;
+ mm_segment_t old_fs;
+
+ if (cmd == IPC_SET) {
+ struct shmid_ds_old tbuf;
+
+ if(copy_from_user (&tbuf, buf, sizeof(*buf)))
+ return -EFAULT;
+ arg.shm_perm = tbuf.shm_perm;
+ arg.shm_segsz = tbuf.shm_segsz;
+ arg.shm_atime = tbuf.shm_atime;
+ arg.shm_dtime = tbuf.shm_dtime;
+ arg.shm_ctime = tbuf.shm_ctime;
+ arg.shm_cpid = tbuf.shm_cpid;
+ arg.shm_lpid = tbuf.shm_lpid;
+ arg.shm_nattch = tbuf.shm_nattch;
+ arg.shm_unused = tbuf.shm_unused;
+ arg.shm_unused2 = tbuf.shm_unused2;
+ arg.shm_unused3 = tbuf.shm_unused3;
+ }
+ old_fs = get_fs ();
+ set_fs (KERNEL_DS);
+ ret = sys_shmctl(shmid, cmd, &arg);
+ set_fs (old_fs);
+ if (ret < 0)
+ return(ret);
+ switch(cmd) {
+ case IPC_INFO:
+ {
+ struct shminfo *tbuf = (struct shminfo *)arg;
+ struct shminfo_old shminfo_oldst;
+
+ shminfo_oldst.shmmax = (tbuf->shmmax > INT_MAX ?
+ INT_MAX : tbuf->shmmax);
+ shminfo_oldst.shmmin = tbuf->shmmin;
+ shminfo_oldst.shmmni = tbuf->shmmni;
+ shminfo_oldst.shmseg = tbuf->shmseg;
+ shminfo_oldst.shmall = tbuf->shmall;
+ if (copy_to_user(buf, &shminfo_oldst,
+ sizeof(struct shminfo_old)))
+ return -EFAULT;
+ return(ret);
+ }
+ case SHM_INFO:
+ {
+ struct shm_info *tbuf = (struct shm_info *)arg;
+
+ if (copy_to_user (buf, tbuf, sizeof(shm_info)))
+ return -EFAULT;
+ return(ret);
+ }
+ case SHM_STAT:
+ case IPC_STAT:
+ {
+ struct shmid_ds_old tbuf;
+
+ tbuf.shm_perm = arg.shm_perm;
+ tbuf.shm_segsz = arg.shm_segsz;
+ tbuf.shm_atime = arg.shm_atime;
+ tbuf.shm_dtime = arg.shm_dtime;
+ tbuf.shm_ctime = arg.shm_ctime;
+ tbuf.shm_cpid = arg.shm_cpid;
+ tbuf.shm_lpid = arg.shm_lpid;
+ tbuf.shm_nattch = arg.shm_nattch;
+ tbuf.shm_unused = arg.shm_unused;
+ tbuf.shm_unused2 = arg.shm_unused2;
+ tbuf.shm_unused3 = arg.shm_unused3;
+ if (copy_to_user (buf, &tbuf, sizeof(tbuf)))
+ return -EFAULT;
+ return(ret);
+ }
+ }
+ return(ret);
}
-
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