Re: [RFC PATCH v1] powerpc: Enable KFENCE for PPC32
From: Christophe Leroy <hidden>
Date: 2021-03-04 14:10:42
Also in:
lkml
Le 04/03/2021 à 13:48, Marco Elver a écrit :
From d118080eb9552073f5dcf1f86198f3d86d5ea850 Mon Sep 17 00:00:00 2001
From: Marco Elver <elver@google.com>
Date: Thu, 4 Mar 2021 13:15:51 +0100
Subject: [PATCH] kfence: fix reports if constant function prefixes exist
Some architectures prefix all functions with a constant string ('.' on
ppc64). Add ARCH_FUNC_PREFIX, which may optionally be defined in
<asm/kfence.h>, so that get_stack_skipnr() can work properly.It works, thanks.
Link: https://lkml.kernel.org/r/f036c53d-7e81-763c-47f4-6024c6c5f058@csgroup.eu Reported-by: Christophe Leroy <redacted> Signed-off-by: Marco Elver <elver@google.com>
Tested-by: Christophe Leroy <redacted>
quoted hunk ↗ jump to hunk
--- mm/kfence/report.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)diff --git a/mm/kfence/report.c b/mm/kfence/report.c index 519f037720f5..e3f71451ad9e 100644 --- a/mm/kfence/report.c +++ b/mm/kfence/report.c@@ -20,6 +20,11 @@ #include "kfence.h" +/* May be overridden by <asm/kfence.h>. */ +#ifndef ARCH_FUNC_PREFIX +#define ARCH_FUNC_PREFIX "" +#endif + extern bool no_hash_pointers; /* Helper function to either print to a seq_file or to console. */@@ -67,8 +72,9 @@ static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries for (skipnr = 0; skipnr < num_entries; skipnr++) { int len = scnprintf(buf, sizeof(buf), "%ps", (void *)stack_entries[skipnr]); - if (str_has_prefix(buf, "kfence_") || str_has_prefix(buf, "__kfence_") || - !strncmp(buf, "__slab_free", len)) { + if (str_has_prefix(buf, ARCH_FUNC_PREFIX "kfence_") || + str_has_prefix(buf, ARCH_FUNC_PREFIX "__kfence_") || + !strncmp(buf, ARCH_FUNC_PREFIX "__slab_free", len)) { /* * In case of tail calls from any of the below * to any of the above.@@ -77,10 +83,10 @@ static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries } /* Also the *_bulk() variants by only checking prefixes. */ - if (str_has_prefix(buf, "kfree") || - str_has_prefix(buf, "kmem_cache_free") || - str_has_prefix(buf, "__kmalloc") || - str_has_prefix(buf, "kmem_cache_alloc")) + if (str_has_prefix(buf, ARCH_FUNC_PREFIX "kfree") || + str_has_prefix(buf, ARCH_FUNC_PREFIX "kmem_cache_free") || + str_has_prefix(buf, ARCH_FUNC_PREFIX "__kmalloc") || + str_has_prefix(buf, ARCH_FUNC_PREFIX "kmem_cache_alloc")) goto found; } if (fallback < num_entries)