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Fix ulock semantics
+12
-12
+11
-7
src/kernel/emulation/linux/psynch/ulock_wait.c
+11
-7
src/kernel/emulation/linux/psynch/ulock_wait.c
···
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#include "ulock_wait.h"
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#include "../base.h"
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#include "../errno.h"
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#include "../duct_errno.h"
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#include <linux-syscalls/linux.h>
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#include "../../../../../platform-include/sys/errno.h"
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#include <stdbool.h>
···
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}
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op = operation & UL_OPCODE_MASK;
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-
if (op == UL_COMPARE_AND_WAIT)
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if (op == UL_COMPARE_AND_WAIT || op == UL_UNFAIR_LOCK)
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{
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ret = LINUX_SYSCALL(__NR_futex, addr, FUTEX_WAIT | FUTEX_PRIVATE_FLAG,
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value, (timeout != 0) ? & ts : NULL);
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-
}
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else if (op == UL_UNFAIR_LOCK)
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{
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// FIXME: This is not correct. Linux sets addr to TID, while libplatform expects Mach thread port
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ret = LINUX_SYSCALL(__NR_futex, addr, FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG,
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value, (timeout != 0) ? & ts : NULL);
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// unlike ulock_wait(), futex(FUTEX_WAIT) does not return how many
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// other threads are now (still) waiting for the lock.
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//
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// This hack makes userspace believe that there are other pending threads
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// and always take the slow path, which is the safe thing to do if
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// we are unsure.
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if (ret == 0 || ret == -LINUX_EAGAIN)
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ret = 1;
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}
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else
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return no_errno ? -(EINVAL | 0x800) : -EINVAL;
+1
-5
src/kernel/emulation/linux/psynch/ulock_wake.c
+1
-5
src/kernel/emulation/linux/psynch/ulock_wake.c
···
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bool no_errno = operation & ULF_NO_ERRNO;
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op = operation & UL_OPCODE_MASK;
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if (op == UL_COMPARE_AND_WAIT)
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if (op == UL_COMPARE_AND_WAIT || op == UL_UNFAIR_LOCK)
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{
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int value;
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···
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ret = LINUX_SYSCALL(__NR_futex, addr, FUTEX_WAKE | FUTEX_PRIVATE_FLAG,
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value);
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-
}
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else if (op == UL_UNFAIR_LOCK)
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{
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ret = LINUX_SYSCALL(__NR_futex, addr, FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG);
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}
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else
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return no_errno ? -(EINVAL | 0x800) : -EINVAL;