Parameter O_NONBLOCK described in man doesn't exist anymore in kernel versions 3.13+ (particularly in commit 3f2b9c9cdf389e303b2273679af08aab5f153517 aka v3.13-rc1~83^2~5), which is quite old, only O_TRUNC parameter present for current kernel version, O_NONBLOCK does nothing. v1 -> v2: added behaviour of syscall for kernel 3.12 and earlier in history section added commit hash to commit message changed word 'actual' to 'current' due to ambigious meaning --- man2/delete_module.2 | 95 +++++++++++++++++++++++++------------------- 1 file changed, 55 insertions(+), 40 deletions(-) diff --git a/man2/delete_module.2 b/man2/delete_module.2 index e9c432e84..d6e7a4bdb 100644 --- a/man2/delete_module.2 +++ b/man2/delete_module.2 @@ -50,42 +50,20 @@ is zero, then the module is immediately unloaded. If a module has a nonzero reference count, then the behavior depends on the bits set in .IR flags . -In normal usage (see NOTES), the -.B O_NONBLOCK -flag is always specified, and the +The .B O_TRUNC flag may additionally be specified. .\" O_TRUNC == KMOD_REMOVE_FORCE in kmod library -.\" O_NONBLOCK == KMOD_REMOVE_NOWAIT in kmod library .IP The various combinations for .I flags have the following effect: .RS .TP -.B flags == O_NONBLOCK -The call returns immediately, with an error. -.TP -.B flags == (O_NONBLOCK | O_TRUNC) +.B flags == O_TRUNC The module is unloaded immediately, regardless of whether it has a nonzero reference count. -.TP -.B (flags & O_NONBLOCK) == 0 -If -.I flags -does not specify -.BR O_NONBLOCK , -the following steps occur: .RS -.IP \[bu] 3 -The module is marked so that no new references are permitted. -.IP \[bu] -If the module's reference count is nonzero, -the caller is placed in an uninterruptible sleep state -.RB ( TASK_UNINTERRUPTIBLE ) -until the reference count is zero, at which point the call unblocks. -.IP \[bu] -The module is unloaded in the usual way. .RE .RE .P @@ -151,11 +129,7 @@ in .TP .B EWOULDBLOCK Other modules depend on this module; -or, -.B O_NONBLOCK -was specified in -.IR flags , -but the reference count of this module is nonzero and +or, the reference count of this module is nonzero and .B O_TRUNC was not specified in .IR flags . @@ -172,6 +146,57 @@ it is (before glibc 2.23) sufficient to manually declare the interface in your code; alternatively, you can invoke the system call using .BR syscall (2). +.SS Linux 3.12 and earlier +In Linux 3.12 and earlier, the system call took two arguments: +.P +.BI " int delete_module(const char *" name ", unsigned int " flags ); +.P +Parameter +.I flags +also can contain +.B O_NONBLOCK +flag in addition to +.B O_TRUNC +flag. Behavior depends on the bits set in +.IR flags . +In normal usage (see NOTES), the +.B O_NONBLOCK +flag is always specified, and the +.B O_TRUNC +flag may additionally be specified. +.\" O_TRUNC == KMOD_REMOVE_FORCE in kmod library +.\" O_NONBLOCK == KMOD_REMOVE_NOWAIT in kmod library +.IP +The various combinations for +.I flags +have the following effect: +.RS +.TP +.B flags == O_NONBLOCK +The call returns immediately, with an error. +.TP +.B flags == (O_NONBLOCK | O_TRUNC) +The module is unloaded immediately, +regardless of whether it has a nonzero reference count. +.TP +.B (flags & O_NONBLOCK) == 0 +If +.I flags +does not specify +.BR O_NONBLOCK , +the following steps occur: +.RS +.IP \[bu] 3 +The module is marked so that no new references are permitted. +.IP \[bu] +If the module's reference count is nonzero, +the caller is placed in an uninterruptible sleep state +.RB ( TASK_UNINTERRUPTIBLE ) +until the reference count is zero, at which point the call unblocks. +.IP \[bu] +The module is unloaded in the usual way. +.RE +.RE .SS Linux 2.4 and earlier In Linux 2.4 and earlier, the system call took only one argument: .P @@ -183,19 +208,9 @@ is NULL, all unused modules marked auto-clean are removed. .P Some further details of differences in the behavior of .BR delete_module () -in Linux 2.4 and earlier are +in Linux 3.12 and earlier are .I not currently explained in this manual page. -.SH NOTES -The uninterruptible sleep that may occur if -.B O_NONBLOCK -is omitted from -.I flags -is considered undesirable, because the sleeping process is left -in an unkillable state. -As at Linux 3.7, specifying -.B O_NONBLOCK -is optional, but in future kernels it is likely to become mandatory. .SH SEE ALSO .BR create_module (2), .BR init_module (2), -- 2.33.8
