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| author | Alejandro Colomar <alx.manpages@gmail.com> | 2021-05-10 19:55:32 +0200 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2021-05-11 17:28:45 +1200 |
| commit | 57d2facb7875b02b0b4d0bd1b5104ba14e1d378c (patch) | |
| tree | b8111977f71a048a0515975e9b3905af7593fcc2 | |
| parent | 0eefb56c953cfd23aea4a51da27f10f22c093461 (diff) | |
| download | man-pages-57d2facb7875b02b0b4d0bd1b5104ba14e1d378c.tar.gz | |
modify_ldt.2: Use syscall(SYS_...); for system calls without a wrapper
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
| -rw-r--r-- | man2/modify_ldt.2 | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/man2/modify_ldt.2 b/man2/modify_ldt.2 index 8ce9ed2526..b67a676906 100644 --- a/man2/modify_ldt.2 +++ b/man2/modify_ldt.2 @@ -27,11 +27,19 @@ modify_ldt \- get or set a per-process LDT entry .SH SYNOPSIS .nf -.BI "int modify_ldt(int " func ", void *" ptr ", unsigned long " bytecount ); +.BR "#include <asm/ldt.h>" " /* Definition of " "struct user_desc" " */" +.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */" +.B #include <unistd.h> +.PP +.BI "int syscall(SYS_modify_ldt, int " func ", void *" ptr , +.BI " unsigned long " bytecount ); .fi .PP .IR Note : -There is no glibc wrapper for this system call; see NOTES. +glibc provides no wrapper for +.BR modify_ldt (), +necessitating the use of +.BR syscall (2). .SH DESCRIPTION .BR modify_ldt () reads or writes the local descriptor table (LDT) for a process. @@ -168,9 +176,6 @@ is neither 0, 1, 2, nor 0x11. This call is Linux-specific and should not be used in programs intended to be portable. .SH NOTES -Glibc does not provide a wrapper for this system call; call it using -.BR syscall (2). -.PP .BR modify_ldt () should not be used for thread-local storage, as it slows down context switches and only supports a limited number of threads. |