kernel.git/drivers/char/hw_random/core.c, branch linux-4.9.y

random: pull add_hwgenerator_randomness() declaration into random.h

2022-06-25T09:45:10Z

commit b777c38239fec5a528e59f55b379e31b1a187524 upstream. add_hwgenerator_randomness() is a function implemented and documented inside of random.c. It is the way that hardware RNGs push data into it. Therefore, it should be declared in random.h. Otherwise sparse complains with: random.c:1137:6: warning: symbol 'add_hwgenerator_randomness' was not declared. Should it be static? The alternative would be to include hw_random.h into random.c, but that wouldn't really be good for anything except slowing down compile time. Cc: Matt Mackall Cc: Theodore Ts'o Acked-by: Herbert Xu Reviewed-by: Eric Biggers Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: remember rng chosen by user

2022-06-25T09:45:10Z

commit 10a515ddb5f19a1ff0b9882c430b4427843169f3 upstream. When a user chooses a rng source via sysfs attribute this rng should be sticky, even when other sources with better quality to register. This patch introduces a simple way to remember the user's choice. This is reflected by a new sysfs attribute file 'rng_selected' which shows if the current rng has been chosen by userspace. The new attribute file shows '1' for user selected rng and '0' otherwise. Signed-off-by: Harald Freudenberger Reviewed-by: PrasannaKumar Muralidharan Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: use rng source with best quality

2022-06-25T09:45:10Z

commit 2bbb6983887fefc8026beab01198d30f47b7bd22 upstream. This patch rewoks the hwrng to always use the rng source with best entropy quality. On registation and unregistration the hwrng now tries to choose the best (= highest quality value) rng source. The handling of the internal list of registered rng sources is now always sorted by quality and the top most rng chosen. Signed-off-by: Harald Freudenberger Reviewed-by: PrasannaKumar Muralidharan Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: core - remove unused PFX macro

2022-06-25T09:45:10Z

commit 079840bd13f793b915f6c8e44452eeb4a0aba8ba upstream. This patch remove the unused PFX macro. Signed-off-by: Corentin Labbe Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: core - Move hwrng miscdev minor number to include/linux/miscdevice.h

2022-06-25T09:45:10Z

commit fd50d71f94fb1c8614098949db068cd4c8dbb91d upstream. This patch move the define for hwrng's miscdev minor number to include/linux/miscdevice.h. It's better that all minor number are in the same place. Rename it to HWRNG_MINOR (from RNG_MISCDEV_MINOR) in he process since no other miscdev define have MISCDEV in their name. Signed-off-by: Corentin Labbe Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: core - Rewrite the header

2022-06-25T09:45:10Z

commit dd8014830d2b1fdf5328978ada706df3ec180c21 upstream. checkpatch have lot of complaint about header. Furthermore, the header have some offtopic/useless information. This patch rewrite a proper header. Signed-off-by: Corentin Labbe Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: core - rewrite better comparison to NULL

2022-06-25T09:45:10Z

commit 2a971e3b248775f808950bdc0ac75f12a2853eff upstream. This patch fix the checkpatch warning "Comparison to NULL could be written "!ptr" Signed-off-by: Corentin Labbe Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: core - do not use multiple blank lines

2022-06-25T09:45:09Z

commit 6bc17d90e62d16828d1a2113b54cfa4e04582fb6 upstream. This patch fix the checkpatch warning "Please don't use multiple blank lines" Signed-off-by: Corentin Labbe Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

hwrng: core - don't wait on add_early_randomness()

2019-10-05T10:30:36Z

commit 78887832e76541f77169a24ac238fccb51059b63 upstream. add_early_randomness() is called by hwrng_register() when the hardware is added. If this hardware and its module are present at boot, and if there is no data available the boot hangs until data are available and can't be interrupted. For instance, in the case of virtio-rng, in some cases the host can be not able to provide enough entropy for all the guests. We can have two easy ways to reproduce the problem but they rely on misconfiguration of the hypervisor or the egd daemon: - if virtio-rng device is configured to connect to the egd daemon of the host but when the virtio-rng driver asks for data the daemon is not connected, - if virtio-rng device is configured to connect to the egd daemon of the host but the egd daemon doesn't provide data. The guest kernel will hang at boot until the virtio-rng driver provides enough data. To avoid that, call rng_get_data() in non-blocking mode (wait=0) from add_early_randomness(). Signed-off-by: Laurent Vivier Fixes: d9e797261933 ("hwrng: add randomness to system from rng...") Cc: Reviewed-by: Theodore Ts'o Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

hwrng: core - Don't use a stack buffer in add_early_randomness()

2016-10-19T03:20:21Z

hw_random carefully avoids using a stack buffer except in add_early_randomness(). This causes a crash in virtio_rng if CONFIG_VMAP_STACK=y. Reported-by: Matt Mullins Tested-by: Matt Mullins Fixes: d3cc7996473a ("hwrng: fetch randomness only after device init") Signed-off-by: Andy Lutomirski Signed-off-by: Herbert Xu