[Crash-utility] Re: [PATCH] X86 64: fix the method for determining whether to enable kalsr

From: Li XingYang <1127955419(a)qq.com&gt; The recently commit 6752571d8d78 fixed the issue where linux kernel with 223b5e57d0d5 ("mm/execmem, arch: convert remaining overrides of module_alloc to execmem") could not load crash, but it did not work in the following two situations: 1： Kernel enables KASAN 2： The kernel set CONFIG_RANDOMIZE_BASE but not set CONFIG_RANDOMIZE_MEMORY crash: seek error: kernel virtual address: ffffffff826bb418 type: "page_offset_base"

In both cases, kaslr_regions will not be exported in /proc/kallsyms, but kaslr_get_random_long will still be exported in /proc/kallsyms. So use kaslr_get_random_long instead of kaslr_degions Determine whether to enable kalsr Signed-off-by: Li XingYang <1127955419(a)qq.com&gt; Signed-off-by: Zach Wade <zachwade.k(a)gmail.com&gt; --- symbols.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/symbols.c b/symbols.c index 69a1fbb..02359a4 100644 --- a/symbols.c +++ b/symbols.c @@ -619,7 +619,7 @@ strip_symbol_end(const char *name, char *buf) * or in /proc/kallsyms on a live system. * * Setting KASLR_CHECK will trigger a search for "module_load_offset" - * or "kaslr_regions" during the initial symbol sort operation, and + * or "kaslr_get_random_long" during the initial symbol sort operation, and * if found, will set (RELOC_AUTO|KASLR). On live systems, the search * is done here by checking /proc/kallsyms. */ @@ -646,7 +646,7 @@ kaslr_init(void) st->_stext_vmlinux = UNINITIALIZED; if (ACTIVE() && /* Linux 3.15 */ - ((symbol_value_from_proc_kallsyms("kaslr_regions") != BADVAL) || + ((symbol_value_from_proc_kallsyms("kaslr_get_random_long") != BADVAL) || (symbol_value_from_proc_kallsyms("module_load_offset") != BADVAL))) { kt->flags2 |= (RELOC_AUTO|KASLR); st->_stext_vmlinux = UNINITIALIZED; @@ -14253,8 +14253,8 @@ numeric_forward(const void *P_x, const void *P_y) st->_stext_vmlinux = valueof(y); } if (kt->flags2 & KASLR_CHECK) { - if (STREQ(x->name, "kaslr_regions") || - STREQ(y->name, "kaslr_regions") || + if (STREQ(x->name, "kaslr_get_random_long") || + STREQ(y->name, "kaslr_get_random_long") || STREQ(x->name, "module_load_offset") || STREQ(y->name, "module_load_offset")) { kt->flags2 &= ~KASLR_CHECK; -- 2.46.1