From 23399c62c1f7ed35345ce520165d7e7ab292d3fa Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 1 Jun 2018 11:28:22 +0200 Subject: [PATCH] lib/vsprintf: Remove atomic-unsafe support for %pCr BugLink: http://bugs.launchpad.net/bugs/1807469 commit 666902e42fd8344b923c02dc5b0f37948ff4f225 upstream. "%pCr" formats the current rate of a clock, and calls clk_get_rate(). The latter obtains a mutex, hence it must not be called from atomic context. Remove support for this rarely-used format, as vsprintf() (and e.g. printk()) must be callable from any context. Any remaining out-of-tree users will start seeing the clock's name printed instead of its rate. Reported-by: Jia-Ju Bai Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks") Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be To: Jia-Ju Bai To: Jonathan Corbet To: Michael Turquette To: Stephen Boyd To: Zhang Rui To: Eduardo Valentin To: Eric Anholt To: Stefan Wahren To: Greg Kroah-Hartman Cc: Sergey Senozhatsky Cc: Petr Mladek Cc: Linus Torvalds Cc: Steven Rostedt Cc: linux-doc@vger.kernel.org Cc: linux-clk@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-renesas-soc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Geert Uytterhoeven Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Geert Uytterhoeven Signed-off-by: Petr Mladek Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: Khalid Elmously --- Documentation/printk-formats.txt | 3 +-- lib/vsprintf.c | 3 --- 2 files changed, 1 insertion(+), 5 deletions(-) diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt index 91199f24ce25..1d8c52fb0f2b 100644 --- a/Documentation/printk-formats.txt +++ b/Documentation/printk-formats.txt @@ -422,11 +422,10 @@ struct clk %pC pll1 %pCn pll1 - %pCr 1560000000 For printing struct clk structures. ``%pC`` and ``%pCn`` print the name (Common Clock Framework) or address (legacy clock framework) of the -structure; ``%pCr`` prints the current clock rate. +structure. Passed by reference. diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 0f21d58f4e66..cf9527513bde 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1447,9 +1447,6 @@ char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, return string(buf, end, NULL, spec); switch (fmt[1]) { - case 'r': - return number(buf, end, clk_get_rate(clk), spec); - case 'n': default: #ifdef CONFIG_COMMON_CLK -- 2.39.2