* [PATCH v2] arm:traps: Don't print stack or raw PC/LR hex values in backtraces
@ 2020-10-16 2:31 Xiaoming Ni
2020-10-26 6:33 ` ping //Re: " Xiaoming Ni
0 siblings, 1 reply; 3+ messages in thread
From: Xiaoming Ni @ 2020-10-16 2:31 UTC (permalink / raw)
To: linux, dima, will, jpoimboe, akpm, christian.brauner, viro,
ldufour, amanieu, walken, ben.dooks, tglx, bigeasy, mingo,
vincent.whitchurch
Cc: linux-arm-kernel, linux-kernel, nixiaoming, wangle6, luohaizheng
Printing raw pointer values in backtraces has potential security
implications and are of questionable value anyway.
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 bb5e5ce545f203 ("x86/dumpstack: Remove kernel text
addresses from stack dump")
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
-------
v2:
Delete [<hex numbers>] from the stack according to the email discussion
in patch V1, Other information processing will be discussed in subsequent
patches.
v1: https://lore.kernel.org/lkml/20201009075957.110017-1-nixiaoming@huawei.com/
1. Don't print stack or raw PC/LR hex values in backtraces
2. Don't print stack mem in backtraces
3. if (!panic_on_oops), Don't print stack mem in __die()
---
arch/arm/kernel/process.c | 3 +--
arch/arm/kernel/traps.c | 4 ++--
2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 8e6ace03e960..71c9e5597d39 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -121,8 +121,7 @@ void __show_regs(struct pt_regs *regs)
printk("PC is at %pS\n", (void *)instruction_pointer(regs));
printk("LR is at %pS\n", (void *)regs->ARM_lr);
- printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n",
- regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
+ printk("psr: %08lx\n", regs->ARM_cpsr);
printk("sp : %08lx ip : %08lx fp : %08lx\n",
regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 17d5a785df28..911bbf164875 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -68,8 +68,8 @@ void dump_backtrace_entry(unsigned long where, unsigned long from,
unsigned long end = frame + 4 + sizeof(struct pt_regs);
#ifdef CONFIG_KALLSYMS
- printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n",
- loglvl, where, (void *)where, from, (void *)from);
+ printk("%s (%ps) from (%pS)\n",
+ loglvl, (void *)where, (void *)from);
#else
printk("%sFunction entered at [<%08lx>] from [<%08lx>]\n",
loglvl, where, from);
--
2.27.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* ping //Re: [PATCH v2] arm:traps: Don't print stack or raw PC/LR hex values in backtraces
2020-10-16 2:31 [PATCH v2] arm:traps: Don't print stack or raw PC/LR hex values in backtraces Xiaoming Ni
@ 2020-10-26 6:33 ` Xiaoming Ni
2020-10-26 17:59 ` Russell King - ARM Linux admin
0 siblings, 1 reply; 3+ messages in thread
From: Xiaoming Ni @ 2020-10-26 6:33 UTC (permalink / raw)
To: linux, dima, will, jpoimboe, akpm, christian.brauner, viro,
ldufour, amanieu, walken, ben.dooks, tglx, bigeasy, mingo,
vincent.whitchurch
Cc: linux-arm-kernel, linux-kernel, wangle6, luohaizheng
ping
On 2020/10/16 10:31, Xiaoming Ni wrote:
> Printing raw pointer values in backtraces has potential security
> implications and are of questionable value anyway.
>
> 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 bb5e5ce545f203 ("x86/dumpstack: Remove kernel text
> addresses from stack dump")
>
> Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
>
> -------
> v2:
> Delete [<hex numbers>] from the stack according to the email discussion
> in patch V1, Other information processing will be discussed in subsequent
> patches.
>
> v1: https://lore.kernel.org/lkml/20201009075957.110017-1-nixiaoming@huawei.com/
> 1. Don't print stack or raw PC/LR hex values in backtraces
> 2. Don't print stack mem in backtraces
> 3. if (!panic_on_oops), Don't print stack mem in __die()
> ---
> arch/arm/kernel/process.c | 3 +--
> arch/arm/kernel/traps.c | 4 ++--
> 2 files changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> index 8e6ace03e960..71c9e5597d39 100644
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -121,8 +121,7 @@ void __show_regs(struct pt_regs *regs)
>
> printk("PC is at %pS\n", (void *)instruction_pointer(regs));
> printk("LR is at %pS\n", (void *)regs->ARM_lr);
> - printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n",
> - regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
> + printk("psr: %08lx\n", regs->ARM_cpsr);
> printk("sp : %08lx ip : %08lx fp : %08lx\n",
> regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
> printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
> diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
> index 17d5a785df28..911bbf164875 100644
> --- a/arch/arm/kernel/traps.c
> +++ b/arch/arm/kernel/traps.c
> @@ -68,8 +68,8 @@ void dump_backtrace_entry(unsigned long where, unsigned long from,
> unsigned long end = frame + 4 + sizeof(struct pt_regs);
>
> #ifdef CONFIG_KALLSYMS
> - printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n",
> - loglvl, where, (void *)where, from, (void *)from);
> + printk("%s (%ps) from (%pS)\n",
> + loglvl, (void *)where, (void *)from);
> #else
> printk("%sFunction entered at [<%08lx>] from [<%08lx>]\n",
> loglvl, where, from);
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: ping //Re: [PATCH v2] arm:traps: Don't print stack or raw PC/LR hex values in backtraces
2020-10-26 6:33 ` ping //Re: " Xiaoming Ni
@ 2020-10-26 17:59 ` Russell King - ARM Linux admin
0 siblings, 0 replies; 3+ messages in thread
From: Russell King - ARM Linux admin @ 2020-10-26 17:59 UTC (permalink / raw)
To: Xiaoming Ni
Cc: dima, will, jpoimboe, akpm, christian.brauner, viro, ldufour,
amanieu, walken, ben.dooks, tglx, bigeasy, mingo,
vincent.whitchurch, linux-arm-kernel, linux-kernel, wangle6,
luohaizheng
On Mon, Oct 26, 2020 at 02:33:10PM +0800, Xiaoming Ni wrote:
> ping
The arm tree was closed due to the merge window, and thus patches do
not get applied at that point. Plus I tend not to review development
patches during the merge window.
> On 2020/10/16 10:31, Xiaoming Ni wrote:
> > Printing raw pointer values in backtraces has potential security
> > implications and are of questionable value anyway.
> >
> > 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 bb5e5ce545f203 ("x86/dumpstack: Remove kernel text
> > addresses from stack dump")
> >
> > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
> >
> > -------
> > v2:
> > Delete [<hex numbers>] from the stack according to the email discussion
> > in patch V1, Other information processing will be discussed in subsequent
> > patches.
> >
> > v1: https://lore.kernel.org/lkml/20201009075957.110017-1-nixiaoming@huawei.com/
> > 1. Don't print stack or raw PC/LR hex values in backtraces
> > 2. Don't print stack mem in backtraces
> > 3. if (!panic_on_oops), Don't print stack mem in __die()
> > ---
> > arch/arm/kernel/process.c | 3 +--
> > arch/arm/kernel/traps.c | 4 ++--
> > 2 files changed, 3 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> > index 8e6ace03e960..71c9e5597d39 100644
> > --- a/arch/arm/kernel/process.c
> > +++ b/arch/arm/kernel/process.c
> > @@ -121,8 +121,7 @@ void __show_regs(struct pt_regs *regs)
> > printk("PC is at %pS\n", (void *)instruction_pointer(regs));
> > printk("LR is at %pS\n", (void *)regs->ARM_lr);
> > - printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n",
> > - regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
> > + printk("psr: %08lx\n", regs->ARM_cpsr);
> > printk("sp : %08lx ip : %08lx fp : %08lx\n",
> > regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
> > printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
> > diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
> > index 17d5a785df28..911bbf164875 100644
> > --- a/arch/arm/kernel/traps.c
> > +++ b/arch/arm/kernel/traps.c
> > @@ -68,8 +68,8 @@ void dump_backtrace_entry(unsigned long where, unsigned long from,
> > unsigned long end = frame + 4 + sizeof(struct pt_regs);
> > #ifdef CONFIG_KALLSYMS
> > - printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n",
> > - loglvl, where, (void *)where, from, (void *)from);
> > + printk("%s (%ps) from (%pS)\n",
> > + loglvl, (void *)where, (void *)from);
> > #else
> > printk("%sFunction entered at [<%08lx>] from [<%08lx>]\n",
> > loglvl, where, from);
> >
>
>
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
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2020-10-16 2:31 [PATCH v2] arm:traps: Don't print stack or raw PC/LR hex values in backtraces Xiaoming Ni
2020-10-26 6:33 ` ping //Re: " Xiaoming Ni
2020-10-26 17:59 ` Russell King - ARM Linux admin
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