Re: svn commit: r346410 - in head: lib/libc/gen share/man/man9 sys/conf sys/libkern sys/sys
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA256
Am Fri, 19 Apr 2019 20:05:48 + (UTC)
Conrad Meyer schrieb:
> Author: cem
> Date: Fri Apr 19 20:05:47 2019
> New Revision: 346410
> URL: https://svnweb.freebsd.org/changeset/base/346410
>
> Log:
> libkern: Bring in arc4random_uniform(9) from libc
>
> It is a useful arc4random wrapper in the kernel for much the same reasons as
> in userspace. Move the source to libkern (because kernel build is
> restricted to sys/, but userspace can include any file it likes) and build
> kernel and libc versions from the same source file.
>
> Copy the documentation from arc4random_uniform(3) to the section 9 page.
>
> While here, add missing arc4random_buf(9) symlink.
>
> Sponsored by: Dell EMC Isilon
>
> Added:
> head/sys/libkern/arc4random_uniform.c
> - copied, changed from r346409, head/lib/libc/gen/arc4random_uniform.c
> Deleted:
> head/lib/libc/gen/arc4random_uniform.c
> Modified:
> head/lib/libc/gen/Makefile.inc
> head/share/man/man9/Makefile
> head/share/man/man9/random.9
> head/sys/conf/files
> head/sys/sys/libkern.h
>
> Modified: head/lib/libc/gen/Makefile.inc
> ==
> --- head/lib/libc/gen/Makefile.incFri Apr 19 19:45:19 2019
> (r346409)
> +++ head/lib/libc/gen/Makefile.incFri Apr 19 20:05:47 2019
> (r346410)
> @@ -3,6 +3,7 @@
>
> # machine-independent gen sources
> .PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/gen ${LIBC_SRCTOP}/gen
> +.PATH: ${SRCTOP}/sys/libkern
>
> CONFS= shells
>
>
> Modified: head/share/man/man9/Makefile
> ==
> --- head/share/man/man9/Makefile Fri Apr 19 19:45:19 2019
> (r346409)
> +++ head/share/man/man9/Makefile Fri Apr 19 20:05:47 2019
> (r346410)
> @@ -1668,6 +1668,8 @@ MLINKS+=psignal.9 gsignal.9 \
> psignal.9 tdsignal.9
> MLINKS+=random.9 arc4rand.9 \
> random.9 arc4random.9 \
> + random.9 arc4random_buf.9 \
> + random.9 arc4random_uniform.9 \
> random.9 is_random_seeded.9 \
> random.9 read_random.9 \
> random.9 read_random_uio.9 \
>
> Modified: head/share/man/man9/random.9
> ==
> --- head/share/man/man9/random.9 Fri Apr 19 19:45:19 2019
> (r346409)
> +++ head/share/man/man9/random.9 Fri Apr 19 20:05:47 2019
> (r346410)
> @@ -26,7 +26,7 @@
> .\"
> .\" $FreeBSD$
> .\" "
> -.Dd April 16, 2019
> +.Dd April 19, 2019
> .Dt RANDOM 9
> .Os
> .Sh NAME
> @@ -45,6 +45,8 @@
> .Fn arc4random "void"
> .Ft void
> .Fn arc4random_buf "void *ptr" "size_t len"
> +.Ft uint32_t
> +.Fn arc4random_uniform "uint32_t upper_bound"
> .Ft void
> .Fn arc4rand "void *ptr" "u_int length" "int reseed"
> .Pp
> @@ -79,6 +81,15 @@ fills
> with
> .Fa len
> bytes of random data.
> +.Pp
> +.Fn arc4random_uniform
> +will return a single 32-bit value, uniformly distributed but less than
> +.Fa upper_bound .
> +This is recommended over constructions like
> +.Dq Li arc4random() % upper_bound
> +as it avoids "modulo bias" when the upper bound is not a power of two.
> +In the worst case, this function may consume multiple iterations
> +to ensure uniformity.
> .Pp
> The
> .Fn arc4rand
>
> Modified: head/sys/conf/files
> ==
> --- head/sys/conf/files Fri Apr 19 19:45:19 2019(r346409)
> +++ head/sys/conf/files Fri Apr 19 20:05:47 2019(r346410)
> @@ -3985,6 +3985,7 @@ kgssapi/gsstest.c optional kgssapi_debug
> # the file should be moved to conf/files. from here.
> #
> libkern/arc4random.c standard
> +libkern/arc4random_uniform.c standard
> crypto/chacha20/chacha.c standard
> libkern/asprintf.c standard
> libkern/bcd.cstandard
>
> Copied and modified: head/sys/libkern/arc4random_uniform.c (from r346409,
> head/lib/libc/gen/arc4random_uniform.c)
> ==
> ---
> head/lib/libc/gen/arc4random_uniform.cFri Apr 19 19:45:19 2019
> (r346409, copy
> source) +++ head/sys/libkern/arc4random_uniform.c Fri Apr 19 20:05:47 2019
> (r346410) @@ -19,7 +19,11 @@ */
>
> #include
> +#ifdef _KERNEL
> +#include
> +#else
> #include
> +#endif
>
> /*
> * Calculate a uniformly distributed random number less than upper_bound
>
> Modified: head/sys/sys/libkern.h
> ==
> --- head/sys/sys/libkern.hFri Apr 19 19:45:19 2019(r346409)
> +++ head/sys/sys/libkern.hFri Apr 19 20:05:47 2019(r346410)
> @@ -128,6 +128,7 @@ struct malloc_type;
> uint32_t arc4random(void);
> void arc4random_buf(void *, size_t);
> void arc4rand(void
Re: svn commit: r346410 - in head: lib/libc/gen share/man/man9 sys/conf sys/libkern sys/sys
O. Hartmann wrote:
> Am Fri, 19 Apr 2019 20:05:48 + (UTC) Conrad Meyer schrieb:
>> Modified: head/lib/libc/gen/Makefile.inc
>> ==
>> --- head/lib/libc/gen/Makefile.inc Fri Apr 19 19:45:19 2019
>> (r346409)
>> +++ head/lib/libc/gen/Makefile.inc Fri Apr 19 20:05:47 2019
>> (r346410)
>> @@ -3,6 +3,7 @@
>
>> # machine-independent gen sources
>> .PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/gen ${LIBC_SRCTOP}/gen
>> +.PATH: ${SRCTOP}/sys/libkern
>
>> CONFS= shells
>
>
> After applying r346410 to our source tree, buildworld fails (WITH_META_MODE
> is set):
>
> [...]
> Building /usr/obj/usr/src/amd64.amd64/lib/libc/ev_timers.o
> --- inet_ntoa.o ---
> In file included from /usr/src/sys/libkern/inet_ntoa.c:34:
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:172:8: error:
> unknown type name 'bool'
> extern bool dynamic_kenv;
>^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:211:5: warning:
> declaration of
> built-in function 'setjmp' requires inclusion of the header
> [-Wbuiltin-requires-header] int setjmp(struct _jmp_buf *)
> __returns_twice; ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:212:6: warning:
> declaration of
> built-in function 'longjmp' requires inclusion of the header
> [-Wbuiltin-requires-header] voidlongjmp(struct _jmp_buf *, int) __dead2; ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:285:6: warning:
> incompatible
> redeclaration of library function 'log'
> [-Wincompatible-library-redeclaration] void
> log(int, const char *, ...) __printflike(2, 3); ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:285:6: note: 'log'
> is a builtin with
> type 'double (double)'
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:382:39: error:
> unknown type name 'uintfptr_t'; did you mean 'uintptr_t'? void
> profclock(int cnt, int
> usermode, uintfptr_t pc); ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/_stdint.h:80:22: note:
> 'uintptr_t' declared
> here typedef __uintptr_t uintptr_t;
>
>
> Is there an include missing?
> Beat me to the initial email. With the specific file change quoted
above, looks like inet_*.c are getting pulled from sys/libkern instead
of the proper lib/libc/inet.
--
Charlie Li
…nope, still don't have an exit line.
(This email address is for mailing list use; replace local-part with
vishwin for off-list communication if possible)
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svn commit: r346410 - in head: lib/libc/gen share/man/man9 sys/conf sys/libkern sys/sys
Author: cem
Date: Fri Apr 19 20:05:47 2019
New Revision: 346410
URL: https://svnweb.freebsd.org/changeset/base/346410
Log:
libkern: Bring in arc4random_uniform(9) from libc
It is a useful arc4random wrapper in the kernel for much the same reasons as
in userspace. Move the source to libkern (because kernel build is
restricted to sys/, but userspace can include any file it likes) and build
kernel and libc versions from the same source file.
Copy the documentation from arc4random_uniform(3) to the section 9 page.
While here, add missing arc4random_buf(9) symlink.
Sponsored by: Dell EMC Isilon
Added:
head/sys/libkern/arc4random_uniform.c
- copied, changed from r346409, head/lib/libc/gen/arc4random_uniform.c
Deleted:
head/lib/libc/gen/arc4random_uniform.c
Modified:
head/lib/libc/gen/Makefile.inc
head/share/man/man9/Makefile
head/share/man/man9/random.9
head/sys/conf/files
head/sys/sys/libkern.h
Modified: head/lib/libc/gen/Makefile.inc
==
--- head/lib/libc/gen/Makefile.inc Fri Apr 19 19:45:19 2019
(r346409)
+++ head/lib/libc/gen/Makefile.inc Fri Apr 19 20:05:47 2019
(r346410)
@@ -3,6 +3,7 @@
# machine-independent gen sources
.PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/gen ${LIBC_SRCTOP}/gen
+.PATH: ${SRCTOP}/sys/libkern
CONFS= shells
Modified: head/share/man/man9/Makefile
==
--- head/share/man/man9/MakefileFri Apr 19 19:45:19 2019
(r346409)
+++ head/share/man/man9/MakefileFri Apr 19 20:05:47 2019
(r346410)
@@ -1668,6 +1668,8 @@ MLINKS+=psignal.9 gsignal.9 \
psignal.9 tdsignal.9
MLINKS+=random.9 arc4rand.9 \
random.9 arc4random.9 \
+ random.9 arc4random_buf.9 \
+ random.9 arc4random_uniform.9 \
random.9 is_random_seeded.9 \
random.9 read_random.9 \
random.9 read_random_uio.9 \
Modified: head/share/man/man9/random.9
==
--- head/share/man/man9/random.9Fri Apr 19 19:45:19 2019
(r346409)
+++ head/share/man/man9/random.9Fri Apr 19 20:05:47 2019
(r346410)
@@ -26,7 +26,7 @@
.\"
.\" $FreeBSD$
.\" "
-.Dd April 16, 2019
+.Dd April 19, 2019
.Dt RANDOM 9
.Os
.Sh NAME
@@ -45,6 +45,8 @@
.Fn arc4random "void"
.Ft void
.Fn arc4random_buf "void *ptr" "size_t len"
+.Ft uint32_t
+.Fn arc4random_uniform "uint32_t upper_bound"
.Ft void
.Fn arc4rand "void *ptr" "u_int length" "int reseed"
.Pp
@@ -79,6 +81,15 @@ fills
with
.Fa len
bytes of random data.
+.Pp
+.Fn arc4random_uniform
+will return a single 32-bit value, uniformly distributed but less than
+.Fa upper_bound .
+This is recommended over constructions like
+.Dq Li arc4random() % upper_bound
+as it avoids "modulo bias" when the upper bound is not a power of two.
+In the worst case, this function may consume multiple iterations
+to ensure uniformity.
.Pp
The
.Fn arc4rand
Modified: head/sys/conf/files
==
--- head/sys/conf/files Fri Apr 19 19:45:19 2019(r346409)
+++ head/sys/conf/files Fri Apr 19 20:05:47 2019(r346410)
@@ -3985,6 +3985,7 @@ kgssapi/gsstest.c optional kgssapi_debug
# the file should be moved to conf/files. from here.
#
libkern/arc4random.c standard
+libkern/arc4random_uniform.c standard
crypto/chacha20/chacha.c standard
libkern/asprintf.c standard
libkern/bcd.c standard
Copied and modified: head/sys/libkern/arc4random_uniform.c (from r346409,
head/lib/libc/gen/arc4random_uniform.c)
==
--- head/lib/libc/gen/arc4random_uniform.c Fri Apr 19 19:45:19 2019
(r346409, copy source)
+++ head/sys/libkern/arc4random_uniform.c Fri Apr 19 20:05:47 2019
(r346410)
@@ -19,7 +19,11 @@
*/
#include
+#ifdef _KERNEL
+#include
+#else
#include
+#endif
/*
* Calculate a uniformly distributed random number less than upper_bound
Modified: head/sys/sys/libkern.h
==
--- head/sys/sys/libkern.h Fri Apr 19 19:45:19 2019(r346409)
+++ head/sys/sys/libkern.h Fri Apr 19 20:05:47 2019(r346410)
@@ -128,6 +128,7 @@ struct malloc_type;
uint32_t arc4random(void);
voidarc4random_buf(void *, size_t);
voidarc4rand(void *, u_int, int);
+uint32_t arc4random_uniform(uint32_t);
int timingsafe_bcmp(const void *, const void *, size_t);
void *bsearch(const void *, const void *, size_t,
size_t, int (*)(const void *, const void *));
___
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To
Re: svn commit: r346410 - in head: lib/libc/gen share/man/man9 sys/conf sys/libkern sys/sys
O. Hartmann wrote:
> Am Fri, 19 Apr 2019 20:05:48 + (UTC) Conrad Meyer schrieb:
>> Modified: head/lib/libc/gen/Makefile.inc
>> ==
>> --- head/lib/libc/gen/Makefile.inc Fri Apr 19 19:45:19 2019
>> (r346409)
>> +++ head/lib/libc/gen/Makefile.inc Fri Apr 19 20:05:47 2019
>> (r346410)
>> @@ -3,6 +3,7 @@
>
>> # machine-independent gen sources
>> .PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/gen ${LIBC_SRCTOP}/gen
>> +.PATH: ${SRCTOP}/sys/libkern
>
>> CONFS= shells
>
>
> After applying r346410 to our source tree, buildworld fails (WITH_META_MODE
> is set):
>
> [...]
> Building /usr/obj/usr/src/amd64.amd64/lib/libc/ev_timers.o
> --- inet_ntoa.o ---
> In file included from /usr/src/sys/libkern/inet_ntoa.c:34:
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:172:8: error:
> unknown type name 'bool'
> extern bool dynamic_kenv;
>^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:211:5: warning:
> declaration of
> built-in function 'setjmp' requires inclusion of the header
> [-Wbuiltin-requires-header] int setjmp(struct _jmp_buf *)
> __returns_twice; ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:212:6: warning:
> declaration of
> built-in function 'longjmp' requires inclusion of the header
> [-Wbuiltin-requires-header] voidlongjmp(struct _jmp_buf *, int) __dead2; ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:285:6: warning:
> incompatible
> redeclaration of library function 'log'
> [-Wincompatible-library-redeclaration] void
> log(int, const char *, ...) __printflike(2, 3); ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:285:6: note: 'log'
> is a builtin with
> type 'double (double)'
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/systm.h:382:39: error:
> unknown type name 'uintfptr_t'; did you mean 'uintptr_t'? void
> profclock(int cnt, int
> usermode, uintfptr_t pc); ^
> /usr/obj/usr/src/amd64.amd64/tmp/usr/include/sys/_stdint.h:80:22: note:
> 'uintptr_t' declared
> here typedef __uintptr_t uintptr_t;
>
>
> Is there an include missing?
> Beat me to the initial email. With the specific file change quoted
above, looks like inet_*.c are getting pulled from sys/libkern instead
of the proper lib/libc/inet.
--
Charlie Li
…nope, still don't have an exit line.
(This email address is for mailing list use; replace local-part with
vishwin for off-list communication if possible)
signature.asc
Description: OpenPGP digital signature
Re: svn commit: r346410 - in head: lib/libc/gen share/man/man9 sys/conf sys/libkern sys/sys
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA256
Am Fri, 19 Apr 2019 20:05:48 + (UTC)
Conrad Meyer schrieb:
> Author: cem
> Date: Fri Apr 19 20:05:47 2019
> New Revision: 346410
> URL: https://svnweb.freebsd.org/changeset/base/346410
>
> Log:
> libkern: Bring in arc4random_uniform(9) from libc
>
> It is a useful arc4random wrapper in the kernel for much the same reasons as
> in userspace. Move the source to libkern (because kernel build is
> restricted to sys/, but userspace can include any file it likes) and build
> kernel and libc versions from the same source file.
>
> Copy the documentation from arc4random_uniform(3) to the section 9 page.
>
> While here, add missing arc4random_buf(9) symlink.
>
> Sponsored by: Dell EMC Isilon
>
> Added:
> head/sys/libkern/arc4random_uniform.c
> - copied, changed from r346409, head/lib/libc/gen/arc4random_uniform.c
> Deleted:
> head/lib/libc/gen/arc4random_uniform.c
> Modified:
> head/lib/libc/gen/Makefile.inc
> head/share/man/man9/Makefile
> head/share/man/man9/random.9
> head/sys/conf/files
> head/sys/sys/libkern.h
>
> Modified: head/lib/libc/gen/Makefile.inc
> ==
> --- head/lib/libc/gen/Makefile.incFri Apr 19 19:45:19 2019
> (r346409)
> +++ head/lib/libc/gen/Makefile.incFri Apr 19 20:05:47 2019
> (r346410)
> @@ -3,6 +3,7 @@
>
> # machine-independent gen sources
> .PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/gen ${LIBC_SRCTOP}/gen
> +.PATH: ${SRCTOP}/sys/libkern
>
> CONFS= shells
>
>
> Modified: head/share/man/man9/Makefile
> ==
> --- head/share/man/man9/Makefile Fri Apr 19 19:45:19 2019
> (r346409)
> +++ head/share/man/man9/Makefile Fri Apr 19 20:05:47 2019
> (r346410)
> @@ -1668,6 +1668,8 @@ MLINKS+=psignal.9 gsignal.9 \
> psignal.9 tdsignal.9
> MLINKS+=random.9 arc4rand.9 \
> random.9 arc4random.9 \
> + random.9 arc4random_buf.9 \
> + random.9 arc4random_uniform.9 \
> random.9 is_random_seeded.9 \
> random.9 read_random.9 \
> random.9 read_random_uio.9 \
>
> Modified: head/share/man/man9/random.9
> ==
> --- head/share/man/man9/random.9 Fri Apr 19 19:45:19 2019
> (r346409)
> +++ head/share/man/man9/random.9 Fri Apr 19 20:05:47 2019
> (r346410)
> @@ -26,7 +26,7 @@
> .\"
> .\" $FreeBSD$
> .\" "
> -.Dd April 16, 2019
> +.Dd April 19, 2019
> .Dt RANDOM 9
> .Os
> .Sh NAME
> @@ -45,6 +45,8 @@
> .Fn arc4random "void"
> .Ft void
> .Fn arc4random_buf "void *ptr" "size_t len"
> +.Ft uint32_t
> +.Fn arc4random_uniform "uint32_t upper_bound"
> .Ft void
> .Fn arc4rand "void *ptr" "u_int length" "int reseed"
> .Pp
> @@ -79,6 +81,15 @@ fills
> with
> .Fa len
> bytes of random data.
> +.Pp
> +.Fn arc4random_uniform
> +will return a single 32-bit value, uniformly distributed but less than
> +.Fa upper_bound .
> +This is recommended over constructions like
> +.Dq Li arc4random() % upper_bound
> +as it avoids "modulo bias" when the upper bound is not a power of two.
> +In the worst case, this function may consume multiple iterations
> +to ensure uniformity.
> .Pp
> The
> .Fn arc4rand
>
> Modified: head/sys/conf/files
> ==
> --- head/sys/conf/files Fri Apr 19 19:45:19 2019(r346409)
> +++ head/sys/conf/files Fri Apr 19 20:05:47 2019(r346410)
> @@ -3985,6 +3985,7 @@ kgssapi/gsstest.c optional kgssapi_debug
> # the file should be moved to conf/files. from here.
> #
> libkern/arc4random.c standard
> +libkern/arc4random_uniform.c standard
> crypto/chacha20/chacha.c standard
> libkern/asprintf.c standard
> libkern/bcd.cstandard
>
> Copied and modified: head/sys/libkern/arc4random_uniform.c (from r346409,
> head/lib/libc/gen/arc4random_uniform.c)
> ==
> ---
> head/lib/libc/gen/arc4random_uniform.cFri Apr 19 19:45:19 2019
> (r346409, copy
> source) +++ head/sys/libkern/arc4random_uniform.c Fri Apr 19 20:05:47 2019
> (r346410) @@ -19,7 +19,11 @@ */
>
> #include
> +#ifdef _KERNEL
> +#include
> +#else
> #include
> +#endif
>
> /*
> * Calculate a uniformly distributed random number less than upper_bound
>
> Modified: head/sys/sys/libkern.h
> ==
> --- head/sys/sys/libkern.hFri Apr 19 19:45:19 2019(r346409)
> +++ head/sys/sys/libkern.hFri Apr 19 20:05:47 2019(r346410)
> @@ -128,6 +128,7 @@ struct malloc_type;
> uint32_t arc4random(void);
> void arc4random_buf(void *, size_t);
> void arc4rand(void
svn commit: r346410 - in head: lib/libc/gen share/man/man9 sys/conf sys/libkern sys/sys
Author: cem
Date: Fri Apr 19 20:05:47 2019
New Revision: 346410
URL: https://svnweb.freebsd.org/changeset/base/346410
Log:
libkern: Bring in arc4random_uniform(9) from libc
It is a useful arc4random wrapper in the kernel for much the same reasons as
in userspace. Move the source to libkern (because kernel build is
restricted to sys/, but userspace can include any file it likes) and build
kernel and libc versions from the same source file.
Copy the documentation from arc4random_uniform(3) to the section 9 page.
While here, add missing arc4random_buf(9) symlink.
Sponsored by: Dell EMC Isilon
Added:
head/sys/libkern/arc4random_uniform.c
- copied, changed from r346409, head/lib/libc/gen/arc4random_uniform.c
Deleted:
head/lib/libc/gen/arc4random_uniform.c
Modified:
head/lib/libc/gen/Makefile.inc
head/share/man/man9/Makefile
head/share/man/man9/random.9
head/sys/conf/files
head/sys/sys/libkern.h
Modified: head/lib/libc/gen/Makefile.inc
==
--- head/lib/libc/gen/Makefile.inc Fri Apr 19 19:45:19 2019
(r346409)
+++ head/lib/libc/gen/Makefile.inc Fri Apr 19 20:05:47 2019
(r346410)
@@ -3,6 +3,7 @@
# machine-independent gen sources
.PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/gen ${LIBC_SRCTOP}/gen
+.PATH: ${SRCTOP}/sys/libkern
CONFS= shells
Modified: head/share/man/man9/Makefile
==
--- head/share/man/man9/MakefileFri Apr 19 19:45:19 2019
(r346409)
+++ head/share/man/man9/MakefileFri Apr 19 20:05:47 2019
(r346410)
@@ -1668,6 +1668,8 @@ MLINKS+=psignal.9 gsignal.9 \
psignal.9 tdsignal.9
MLINKS+=random.9 arc4rand.9 \
random.9 arc4random.9 \
+ random.9 arc4random_buf.9 \
+ random.9 arc4random_uniform.9 \
random.9 is_random_seeded.9 \
random.9 read_random.9 \
random.9 read_random_uio.9 \
Modified: head/share/man/man9/random.9
==
--- head/share/man/man9/random.9Fri Apr 19 19:45:19 2019
(r346409)
+++ head/share/man/man9/random.9Fri Apr 19 20:05:47 2019
(r346410)
@@ -26,7 +26,7 @@
.\"
.\" $FreeBSD$
.\" "
-.Dd April 16, 2019
+.Dd April 19, 2019
.Dt RANDOM 9
.Os
.Sh NAME
@@ -45,6 +45,8 @@
.Fn arc4random "void"
.Ft void
.Fn arc4random_buf "void *ptr" "size_t len"
+.Ft uint32_t
+.Fn arc4random_uniform "uint32_t upper_bound"
.Ft void
.Fn arc4rand "void *ptr" "u_int length" "int reseed"
.Pp
@@ -79,6 +81,15 @@ fills
with
.Fa len
bytes of random data.
+.Pp
+.Fn arc4random_uniform
+will return a single 32-bit value, uniformly distributed but less than
+.Fa upper_bound .
+This is recommended over constructions like
+.Dq Li arc4random() % upper_bound
+as it avoids "modulo bias" when the upper bound is not a power of two.
+In the worst case, this function may consume multiple iterations
+to ensure uniformity.
.Pp
The
.Fn arc4rand
Modified: head/sys/conf/files
==
--- head/sys/conf/files Fri Apr 19 19:45:19 2019(r346409)
+++ head/sys/conf/files Fri Apr 19 20:05:47 2019(r346410)
@@ -3985,6 +3985,7 @@ kgssapi/gsstest.c optional kgssapi_debug
# the file should be moved to conf/files. from here.
#
libkern/arc4random.c standard
+libkern/arc4random_uniform.c standard
crypto/chacha20/chacha.c standard
libkern/asprintf.c standard
libkern/bcd.c standard
Copied and modified: head/sys/libkern/arc4random_uniform.c (from r346409,
head/lib/libc/gen/arc4random_uniform.c)
==
--- head/lib/libc/gen/arc4random_uniform.c Fri Apr 19 19:45:19 2019
(r346409, copy source)
+++ head/sys/libkern/arc4random_uniform.c Fri Apr 19 20:05:47 2019
(r346410)
@@ -19,7 +19,11 @@
*/
#include
+#ifdef _KERNEL
+#include
+#else
#include
+#endif
/*
* Calculate a uniformly distributed random number less than upper_bound
Modified: head/sys/sys/libkern.h
==
--- head/sys/sys/libkern.h Fri Apr 19 19:45:19 2019(r346409)
+++ head/sys/sys/libkern.h Fri Apr 19 20:05:47 2019(r346410)
@@ -128,6 +128,7 @@ struct malloc_type;
uint32_t arc4random(void);
voidarc4random_buf(void *, size_t);
voidarc4rand(void *, u_int, int);
+uint32_t arc4random_uniform(uint32_t);
int timingsafe_bcmp(const void *, const void *, size_t);
void *bsearch(const void *, const void *, size_t,
size_t, int (*)(const void *, const void *));
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