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| | 22 | .Dd May 1, 2020 |
| | 23 | .Dt PTHREAD_JIT_WRITE_PROTECT_NP 3 |
| | 24 | .Os |
| | 25 | .Sh NAME |
| | 26 | .Nm pthread_jit_write_protect_supported_np , |
| | 27 | .Nm pthread_jit_write_protect_np |
| | 28 | .Nd thread JIT region write protection settings |
| | 29 | .Sh SYNOPSIS |
| | 30 | .In pthread.h |
| | 31 | .Ft int |
| | 32 | .Fn pthread_jit_write_protect_supported_np "void" |
| | 33 | .Ft void |
| | 34 | .Fn pthread_jit_write_protect_np "int enabled" |
| | 35 | .Sh DESCRIPTION |
| | 36 | The |
| | 37 | .Fn pthread_jit_write_protect_supported_np |
| | 38 | function returns whether the |
| | 39 | .Fn pthread_jit_write_protect_np |
| | 40 | API is supported on this platform. If |
| | 41 | .Fn pthread_jit_write_protect_np |
| | 42 | API is supported on this platform, |
| | 43 | .Fn pthread_jit_write_protect_np |
| | 44 | must be called to toggle per-thread write protection on the MAP_JIT region before the thread writes to or executes from the MAP_JIT region. |
| | 45 | .Pp |
| | 46 | The |
| | 47 | .Fn pthread_jit_write_protect_np |
| | 48 | function sets whether MAP_JIT region write protection is enabled for this thread. |
| | 49 | .Pp |
| | 50 | On platforms where |
| | 51 | .Fn pthread_jit_write_protect_supported_np |
| | 52 | is true, MAP_JIT regions are never writeable and executable simultaneously. |
| | 53 | When write protection is enabled for the thread, writes by the thread to the MAP_JIT region are denied and the MAP_JIT region is executable. |
| | 54 | When write protection is disabled for the thread, writes by the thread to the MAP_JIT region are allowed and the MAP_JIT region is not executable. |
| | 55 | Pass a non-zero value for the |
| | 56 | .Fa enabled |
| | 57 | parameter to enable thread JIT region write protection and allow execution. Pass a zero value for the |
| | 58 | .Fa enabled |
| | 59 | parameter to disable thread JIT write protection and deny execution. |
| | 60 | .Pp |
| | 61 | On platforms where |
| | 62 | .Fn pthread_jit_write_protect_supported_np |
| | 63 | is not supported, MAP_JIT regions are both simultaenously writeable and executable. Calls to |
| | 64 | .Fn pthread_jit_write_protect_np |
| | 65 | are no-ops on unsupported platforms. |
| | 66 | .Sh RETURN VALUES |
| | 67 | If supported, the |
| | 68 | .Fn pthread_jit_write_protect_supported_np |
| | 69 | function will return one. Otherwise the function will return zero. |
| | 70 | .Sh SEE ALSO |
| | 71 | .Xr mmap 2 |
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