Messages in this thread Patch in this message | | | From | Xiaoming Ni <> | Subject | [PATCH] arm:traps:Don't dump the memory in non-system reset scenarios | Date | Mon, 26 Oct 2020 14:31:06 +0800 |
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Do not dump the memory in non-system reset scenarios to prevent virtual address information leakage.
This patch follows x86 and arm64's lead and removes the "Exception stack:" dump from kernel backtraces: commit a25ffd3a6302a6 ("arm64: traps: Don't print stack or raw PC/LR values in backtraces") commit 0ee1dd9f5e7eae ("x86/dumpstack: Remove raw stack dump")
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> --- arch/arm/kernel/traps.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 911bbf164875..34e268378972 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -60,13 +60,9 @@ static int __init user_debug_setup(char *str) __setup("user_debug=", user_debug_setup); #endif -static void dump_mem(const char *, const char *, unsigned long, unsigned long); - void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame, const char *loglvl) { - unsigned long end = frame + 4 + sizeof(struct pt_regs); - #ifdef CONFIG_KALLSYMS printk("%s (%ps) from (%pS)\n", loglvl, (void *)where, (void *)from); @@ -74,9 +70,6 @@ void dump_backtrace_entry(unsigned long where, unsigned long from, printk("%sFunction entered at [<%08lx>] from [<%08lx>]\n", loglvl, where, from); #endif - - if (in_entry_text(from) && end <= ALIGN(frame, THREAD_SIZE)) - dump_mem(loglvl, "Exception stack", frame + 4, end); } void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl) @@ -125,6 +118,12 @@ static void dump_mem(const char *lvl, const char *str, unsigned long bottom, mm_segment_t fs; int i; + /* + * To prevent virtual address information leakage, memory + * information cannot be printed in non-reset scenarios. + */ + if (panic_on_oops == 0) + return; /* * We need to switch to kernel mode so that we can use __get_user * to safely read from kernel space. Note that we now dump the -- 2.27.0
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