linux-kernel - [PATCH 3.16 10/10] percpu: stop printing kernel addresses

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Message-ID: <lsq.1557410897.661826111@decadent.org.uk>
Date:   Thu, 09 May 2019 15:08:17 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, Denis Kirjanov <kda@...ux-powerpc.org>,
        "Greg Kroah-Hartman" <gregkh@...uxfoundation.org>,
        "Matteo Croce" <mcroce@...hat.com>,
        "Dennis Zhou" <dennis@...nel.org>
Subject: [PATCH 3.16 10/10] percpu: stop printing kernel addresses

3.16.67-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Matteo Croce <mcroce@...hat.com>

commit 00206a69ee32f03e6f40837684dcbe475ea02266 upstream.

Since commit ad67b74d2469d9b8 ("printk: hash addresses printed with %p"),
at boot "____ptrval____" is printed instead of actual addresses:

    percpu: Embedded 38 pages/cpu @(____ptrval____) s124376 r0 d31272 u524288

Instead of changing the print to "%px", and leaking kernel addresses,
just remove the print completely, cfr. e.g. commit 071929dbdd865f77
("arm64: Stop printing the virtual memory layout").

Signed-off-by: Matteo Croce <mcroce@...hat.com>
Signed-off-by: Dennis Zhou <dennis@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 mm/percpu.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1716,8 +1716,8 @@ int __init pcpu_embed_first_chunk(size_t
 #endif
 	}
 
-	pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n",
-		PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size,
+	pr_info("PERCPU: Embedded %zu pages/cpu s%zu r%zu d%zu u%zu\n",
+		PFN_DOWN(size_sum), ai->static_size, ai->reserved_size,
 		ai->dyn_size, ai->unit_size);
 
 	rc = pcpu_setup_first_chunk(ai, base);
@@ -1830,8 +1830,8 @@ int __init pcpu_page_first_chunk(size_t
 	}
 
 	/* we're ready, commit */
-	pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n",
-		unit_pages, psize_str, vm.addr, ai->static_size,
+	pr_info("PERCPU: %d %s pages/cpu s%zu r%zu d%zu\n",
+		unit_pages, psize_str, ai->static_size,
 		ai->reserved_size, ai->dyn_size);
 
 	rc = pcpu_setup_first_chunk(ai, vm.addr);