Messages in this thread Patch in this message | | | Date | Mon, 25 Jun 2018 14:04:54 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH RESEND] lib/test_printf.c: call wait_for_random_bytes() before plain %p tests |
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On Mon 2018-06-25 09:50:20, Petr Mladek wrote: > On Fri 2018-06-22 23:50:20, Thierry Escande wrote: > > On 22/06/2018 22:53, Steven Rostedt wrote: > > > On Thu, Jun 07, 2018 at 02:24:34PM +0200, Petr Mladek wrote: > > > > On Mon 2018-06-04 13:37:08, Thierry Escande wrote: > > > > > If the test_printf module is loaded before the crng is initialized, the > > > > > plain 'p' tests will fail because the printed address will not be hashed > > > > > and the buffer will contain '(ptrval)' instead. > > > > > This patch adds a call to wait_for_random_bytes() before plain 'p' tests > > > > > to make sure the crng is initialized. > > > > > > > > Hmm, my system did not boot with this patch and > > > > CONFIG_TEST_PRINTF=y > > > > > > And neither does my test box. It killed my tests I was running, as one of the > > > configs I test has this set. > > > > > > It appears that Andrew pulled it in and sent it to Linus, as it is in > > > 4.18-rc1, and I need to now revert this patch to make my tests work. > > > > This patch has been superseded with a v2 and a v3 pushed into Petr > > printk.git tree (https://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk.git/commit/?h=for-4.19&id=ce041c43f22298485122bab15c14d062383fbc67). > > Sorry for the mess... > > Andrew, > > should I send the revert and the better fix to Linus or would you like > to do so?
Below is the proposed revert-commit just in case people want to add Reviewed-by tags or so.
From 043f891b70e6197bc181f3b087c2bd04c60fddd2 Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@suse.com> Date: Mon, 25 Jun 2018 13:28:06 +0200 Subject: [PATCH] Revert "lib/test_printf.c: call wait_for_random_bytes() before plain %p tests"
This reverts commit ee410f15b1418f2f4428e79980674c979081bcb7.
It might prevent the machine from boot. It would wait for enough randomness at the very beginning of kernel_init(). But there is basically nothing running in parallel that would help to produce any randomness.
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Petr Mladek <pmladek@suse.com> --- lib/test_printf.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/lib/test_printf.c b/lib/test_printf.c index b2aa8f514844..cea592f402ed 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -260,13 +260,6 @@ plain(void) { int err; - /* - * Make sure crng is ready. Otherwise we get "(ptrval)" instead - * of a hashed address when printing '%p' in plain_hash() and - * plain_format(). - */ - wait_for_random_bytes(); - err = plain_hash(); if (err) { pr_warn("plain 'p' does not appear to be hashed\n"); -- 2.13.7
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