56dc79cea0
- rewrite the semop(2) implementation so that it now conforms to the specification, including atomicity, support for blocking more than once, range checks, but also basic fairness support; - fix permissions checking; - fix missing time adjustments; - fix off-by-one errors and other bugs; - do not allocate dynamic memory for GETALL/SETALL; - add test88, which properly tests the semaphore functionality. Change-Id: I85f0d3408c0d6bba41cfb4c91a34c8b46b2a5959
33 lines
600 B
C
33 lines
600 B
C
#include "inc.h"
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int
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check_perm(struct ipc_perm * req, endpoint_t who, int mode)
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{
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int req_mode;
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uid_t uid;
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gid_t gid;
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uid = getnuid(who);
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gid = getngid(who);
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mode &= 0700;
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/* Root is allowed to do anything. */
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if (uid == 0)
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return TRUE;
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if (uid == req->uid || uid == req->cuid) {
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/* Same user. */
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req_mode = req->mode & 0700;
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} else if (gid == req->gid || gid == req->cgid) {
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/* Same group. */
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req_mode = req->mode & 0070;
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mode >>= 3;
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} else {
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/* Other user and group. */
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req_mode = req->mode & 0007;
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mode >>= 6;
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}
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return (mode && ((mode & req_mode) == mode));
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}
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