* [PATCH] x86/traps: Remove redundant trapnr parameter from fatal_trap()
@ 2014-09-01 10:06 Andrew Cooper
2014-09-01 16:10 ` Don Slutz
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Cooper @ 2014-09-01 10:06 UTC (permalink / raw)
To: Xen-devel; +Cc: Andrew Cooper, Jan Beulich
It is always available via regs->entry_vector.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Jan Beulich <JBeulich@suse.com>
---
xen/arch/x86/cpu/mcheck/mce.c | 2 +-
xen/arch/x86/nmi.c | 2 +-
xen/arch/x86/traps.c | 13 +++++++------
xen/arch/x86/x86_64/entry.S | 3 +--
xen/include/asm-x86/processor.h | 2 +-
5 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/xen/arch/x86/cpu/mcheck/mce.c b/xen/arch/x86/cpu/mcheck/mce.c
index 812daf6..05a86fb 100644
--- a/xen/arch/x86/cpu/mcheck/mce.c
+++ b/xen/arch/x86/cpu/mcheck/mce.c
@@ -74,7 +74,7 @@ static void unexpected_machine_check(const struct cpu_user_regs *regs)
{
console_force_unlock();
printk("Unexpected Machine Check Exception\n");
- fatal_trap(TRAP_machine_check, regs);
+ fatal_trap(regs);
}
diff --git a/xen/arch/x86/nmi.c b/xen/arch/x86/nmi.c
index 7d15d5b..055f4ef 100644
--- a/xen/arch/x86/nmi.c
+++ b/xen/arch/x86/nmi.c
@@ -472,7 +472,7 @@ bool_t nmi_watchdog_tick(const struct cpu_user_regs *regs)
console_force_unlock();
printk("Watchdog timer detects that CPU%d is stuck!\n",
smp_processor_id());
- fatal_trap(TRAP_nmi, regs);
+ fatal_trap(regs);
}
}
else
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 7f5306f..10fc2ca 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -394,9 +394,10 @@ static const char *trapstr(unsigned int trapnr)
* are disabled). In such situations we can't do much that is safe. We try to
* print out some tracing and then we just spin.
*/
-void fatal_trap(int trapnr, const struct cpu_user_regs *regs)
+void fatal_trap(const struct cpu_user_regs *regs)
{
static DEFINE_PER_CPU(char, depth);
+ unsigned int trapnr = regs->entry_vector;
/* Set AC to reduce chance of further SMAP faults */
stac();
@@ -1427,7 +1428,7 @@ void do_page_fault(struct cpu_user_regs *regs)
{
console_start_sync();
printk("Xen SM%cP violation\n", (pf_type == smep_fault) ? 'E' : 'A');
- fatal_trap(TRAP_page_fault, regs);
+ fatal_trap(regs);
}
if ( pf_type != real_fault )
@@ -1498,7 +1499,7 @@ void __init do_early_page_fault(struct cpu_user_regs *regs)
console_start_sync();
printk("Early fatal page fault at %04x:%p (cr2=%p, ec=%04x)\n",
regs->cs, _p(regs->eip), _p(cr2), regs->error_code);
- fatal_trap(TRAP_page_fault, regs);
+ fatal_trap(regs);
}
}
@@ -3256,7 +3257,7 @@ static void pci_serr_error(const struct cpu_user_regs *regs)
default: /* 'fatal' */
console_force_unlock();
printk("\n\nNMI - PCI system error (SERR)\n");
- fatal_trap(TRAP_nmi, regs);
+ fatal_trap(regs);
}
}
@@ -3271,7 +3272,7 @@ static void io_check_error(const struct cpu_user_regs *regs)
default: /* 'fatal' */
console_force_unlock();
printk("\n\nNMI - I/O ERROR\n");
- fatal_trap(TRAP_nmi, regs);
+ fatal_trap(regs);
}
outb((inb(0x61) & 0x0f) | 0x08, 0x61); /* clear-and-disable IOCK */
@@ -3291,7 +3292,7 @@ static void unknown_nmi_error(const struct cpu_user_regs *regs, unsigned char re
console_force_unlock();
printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
printk("Do you have a strange power saving mode enabled?\n");
- fatal_trap(TRAP_nmi, regs);
+ fatal_trap(regs);
}
}
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index a3ed216..42835d0 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -536,8 +536,7 @@ exception_with_ints_disabled:
/* No special register assumptions. */
FATAL_exception_with_ints_disabled:
- movzbl UREGS_entry_vector(%rsp),%edi
- movq %rsp,%rsi
+ movq %rsp,%rdi
call fatal_trap
ud2
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index a156e01..9e1f210 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -481,7 +481,7 @@ void show_registers(const struct cpu_user_regs *regs);
void show_execution_state(const struct cpu_user_regs *regs);
#define dump_execution_state() run_in_exception_handler(show_execution_state)
void show_page_walk(unsigned long addr);
-void noreturn fatal_trap(int trapnr, const struct cpu_user_regs *regs);
+void noreturn fatal_trap(const struct cpu_user_regs *regs);
void compat_show_guest_stack(struct vcpu *v,
const struct cpu_user_regs *regs, int lines);
--
1.7.10.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] x86/traps: Remove redundant trapnr parameter from fatal_trap()
2014-09-01 10:06 [PATCH] x86/traps: Remove redundant trapnr parameter from fatal_trap() Andrew Cooper
@ 2014-09-01 16:10 ` Don Slutz
2014-09-01 16:27 ` Andrew Cooper
0 siblings, 1 reply; 4+ messages in thread
From: Don Slutz @ 2014-09-01 16:10 UTC (permalink / raw)
To: Andrew Cooper; +Cc: Jan Beulich, Xen-devel
On 09/01/14 06:06, Andrew Cooper wrote:
> It is always available via regs->entry_vector.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> CC: Jan Beulich <JBeulich@suse.com>
> ---
> xen/arch/x86/cpu/mcheck/mce.c | 2 +-
> xen/arch/x86/nmi.c | 2 +-
> xen/arch/x86/traps.c | 13 +++++++------
> xen/arch/x86/x86_64/entry.S | 3 +--
> xen/include/asm-x86/processor.h | 2 +-
> 5 files changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/xen/arch/x86/cpu/mcheck/mce.c b/xen/arch/x86/cpu/mcheck/mce.c
> index 812daf6..05a86fb 100644
> --- a/xen/arch/x86/cpu/mcheck/mce.c
> +++ b/xen/arch/x86/cpu/mcheck/mce.c
> @@ -74,7 +74,7 @@ static void unexpected_machine_check(const struct cpu_user_regs *regs)
> {
> console_force_unlock();
> printk("Unexpected Machine Check Exception\n");
> - fatal_trap(TRAP_machine_check, regs);
> + fatal_trap(regs);
> }
>
>
> diff --git a/xen/arch/x86/nmi.c b/xen/arch/x86/nmi.c
> index 7d15d5b..055f4ef 100644
> --- a/xen/arch/x86/nmi.c
> +++ b/xen/arch/x86/nmi.c
> @@ -472,7 +472,7 @@ bool_t nmi_watchdog_tick(const struct cpu_user_regs *regs)
> console_force_unlock();
> printk("Watchdog timer detects that CPU%d is stuck!\n",
> smp_processor_id());
> - fatal_trap(TRAP_nmi, regs);
> + fatal_trap(regs);
> }
> }
> else
> diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
> index 7f5306f..10fc2ca 100644
> --- a/xen/arch/x86/traps.c
> +++ b/xen/arch/x86/traps.c
> @@ -394,9 +394,10 @@ static const char *trapstr(unsigned int trapnr)
> * are disabled). In such situations we can't do much that is safe. We try to
> * print out some tracing and then we just spin.
> */
> -void fatal_trap(int trapnr, const struct cpu_user_regs *regs)
> +void fatal_trap(const struct cpu_user_regs *regs)
> {
> static DEFINE_PER_CPU(char, depth);
> + unsigned int trapnr = regs->entry_vector;
Should this be:
unsigned int trapnr = regs->entry_vector & ~(TRAP_regs_partial|TRAP_syscall);
To get rid of the extra bits?
-Don Slutz
>
> /* Set AC to reduce chance of further SMAP faults */
> stac();
> @@ -1427,7 +1428,7 @@ void do_page_fault(struct cpu_user_regs *regs)
> {
> console_start_sync();
> printk("Xen SM%cP violation\n", (pf_type == smep_fault) ? 'E' : 'A');
> - fatal_trap(TRAP_page_fault, regs);
> + fatal_trap(regs);
> }
>
> if ( pf_type != real_fault )
> @@ -1498,7 +1499,7 @@ void __init do_early_page_fault(struct cpu_user_regs *regs)
> console_start_sync();
> printk("Early fatal page fault at %04x:%p (cr2=%p, ec=%04x)\n",
> regs->cs, _p(regs->eip), _p(cr2), regs->error_code);
> - fatal_trap(TRAP_page_fault, regs);
> + fatal_trap(regs);
> }
> }
>
> @@ -3256,7 +3257,7 @@ static void pci_serr_error(const struct cpu_user_regs *regs)
> default: /* 'fatal' */
> console_force_unlock();
> printk("\n\nNMI - PCI system error (SERR)\n");
> - fatal_trap(TRAP_nmi, regs);
> + fatal_trap(regs);
> }
> }
>
> @@ -3271,7 +3272,7 @@ static void io_check_error(const struct cpu_user_regs *regs)
> default: /* 'fatal' */
> console_force_unlock();
> printk("\n\nNMI - I/O ERROR\n");
> - fatal_trap(TRAP_nmi, regs);
> + fatal_trap(regs);
> }
>
> outb((inb(0x61) & 0x0f) | 0x08, 0x61); /* clear-and-disable IOCK */
> @@ -3291,7 +3292,7 @@ static void unknown_nmi_error(const struct cpu_user_regs *regs, unsigned char re
> console_force_unlock();
> printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
> printk("Do you have a strange power saving mode enabled?\n");
> - fatal_trap(TRAP_nmi, regs);
> + fatal_trap(regs);
> }
> }
>
> diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
> index a3ed216..42835d0 100644
> --- a/xen/arch/x86/x86_64/entry.S
> +++ b/xen/arch/x86/x86_64/entry.S
> @@ -536,8 +536,7 @@ exception_with_ints_disabled:
>
> /* No special register assumptions. */
> FATAL_exception_with_ints_disabled:
> - movzbl UREGS_entry_vector(%rsp),%edi
> - movq %rsp,%rsi
> + movq %rsp,%rdi
> call fatal_trap
> ud2
>
> diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
> index a156e01..9e1f210 100644
> --- a/xen/include/asm-x86/processor.h
> +++ b/xen/include/asm-x86/processor.h
> @@ -481,7 +481,7 @@ void show_registers(const struct cpu_user_regs *regs);
> void show_execution_state(const struct cpu_user_regs *regs);
> #define dump_execution_state() run_in_exception_handler(show_execution_state)
> void show_page_walk(unsigned long addr);
> -void noreturn fatal_trap(int trapnr, const struct cpu_user_regs *regs);
> +void noreturn fatal_trap(const struct cpu_user_regs *regs);
>
> void compat_show_guest_stack(struct vcpu *v,
> const struct cpu_user_regs *regs, int lines);
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] x86/traps: Remove redundant trapnr parameter from fatal_trap()
2014-09-01 16:10 ` Don Slutz
@ 2014-09-01 16:27 ` Andrew Cooper
2014-09-07 0:18 ` Don Slutz
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Cooper @ 2014-09-01 16:27 UTC (permalink / raw)
To: Don Slutz; +Cc: Jan Beulich, Xen-devel
On 01/09/14 17:10, Don Slutz wrote:
> On 09/01/14 06:06, Andrew Cooper wrote:
>> It is always available via regs->entry_vector.
>>
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>> CC: Jan Beulich <JBeulich@suse.com>
>> ---
>> xen/arch/x86/cpu/mcheck/mce.c | 2 +-
>> xen/arch/x86/nmi.c | 2 +-
>> xen/arch/x86/traps.c | 13 +++++++------
>> xen/arch/x86/x86_64/entry.S | 3 +--
>> xen/include/asm-x86/processor.h | 2 +-
>> 5 files changed, 11 insertions(+), 11 deletions(-)
>>
>> diff --git a/xen/arch/x86/cpu/mcheck/mce.c
>> b/xen/arch/x86/cpu/mcheck/mce.c
>> index 812daf6..05a86fb 100644
>> --- a/xen/arch/x86/cpu/mcheck/mce.c
>> +++ b/xen/arch/x86/cpu/mcheck/mce.c
>> @@ -74,7 +74,7 @@ static void unexpected_machine_check(const struct
>> cpu_user_regs *regs)
>> {
>> console_force_unlock();
>> printk("Unexpected Machine Check Exception\n");
>> - fatal_trap(TRAP_machine_check, regs);
>> + fatal_trap(regs);
>> }
>> diff --git a/xen/arch/x86/nmi.c b/xen/arch/x86/nmi.c
>> index 7d15d5b..055f4ef 100644
>> --- a/xen/arch/x86/nmi.c
>> +++ b/xen/arch/x86/nmi.c
>> @@ -472,7 +472,7 @@ bool_t nmi_watchdog_tick(const struct
>> cpu_user_regs *regs)
>> console_force_unlock();
>> printk("Watchdog timer detects that CPU%d is stuck!\n",
>> smp_processor_id());
>> - fatal_trap(TRAP_nmi, regs);
>> + fatal_trap(regs);
>> }
>> }
>> else
>> diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
>> index 7f5306f..10fc2ca 100644
>> --- a/xen/arch/x86/traps.c
>> +++ b/xen/arch/x86/traps.c
>> @@ -394,9 +394,10 @@ static const char *trapstr(unsigned int trapnr)
>> * are disabled). In such situations we can't do much that is safe.
>> We try to
>> * print out some tracing and then we just spin.
>> */
>> -void fatal_trap(int trapnr, const struct cpu_user_regs *regs)
>> +void fatal_trap(const struct cpu_user_regs *regs)
>> {
>> static DEFINE_PER_CPU(char, depth);
>> + unsigned int trapnr = regs->entry_vector;
>
> Should this be:
>
> unsigned int trapnr = regs->entry_vector &
> ~(TRAP_regs_partial|TRAP_syscall);
>
>
> To get rid of the extra bits?
>
> -Don Slutz
No; I don't think so. There should be no paths into fatal_trap() which
would set these bits, as these bits are only set as a result of guest
sys/hypercall interaction, while fatal_trap() is a terminal error condition.
Furthermore, if a path is discovered then a) it will be more obvious
from the error message and b) we probably have a security problem to fix.
~Andrew
>
>> /* Set AC to reduce chance of further SMAP faults */
>> stac();
>> @@ -1427,7 +1428,7 @@ void do_page_fault(struct cpu_user_regs *regs)
>> {
>> console_start_sync();
>> printk("Xen SM%cP violation\n", (pf_type == smep_fault)
>> ? 'E' : 'A');
>> - fatal_trap(TRAP_page_fault, regs);
>> + fatal_trap(regs);
>> }
>> if ( pf_type != real_fault )
>> @@ -1498,7 +1499,7 @@ void __init do_early_page_fault(struct
>> cpu_user_regs *regs)
>> console_start_sync();
>> printk("Early fatal page fault at %04x:%p (cr2=%p,
>> ec=%04x)\n",
>> regs->cs, _p(regs->eip), _p(cr2), regs->error_code);
>> - fatal_trap(TRAP_page_fault, regs);
>> + fatal_trap(regs);
>> }
>> }
>> @@ -3256,7 +3257,7 @@ static void pci_serr_error(const struct
>> cpu_user_regs *regs)
>> default: /* 'fatal' */
>> console_force_unlock();
>> printk("\n\nNMI - PCI system error (SERR)\n");
>> - fatal_trap(TRAP_nmi, regs);
>> + fatal_trap(regs);
>> }
>> }
>> @@ -3271,7 +3272,7 @@ static void io_check_error(const struct
>> cpu_user_regs *regs)
>> default: /* 'fatal' */
>> console_force_unlock();
>> printk("\n\nNMI - I/O ERROR\n");
>> - fatal_trap(TRAP_nmi, regs);
>> + fatal_trap(regs);
>> }
>> outb((inb(0x61) & 0x0f) | 0x08, 0x61); /* clear-and-disable
>> IOCK */
>> @@ -3291,7 +3292,7 @@ static void unknown_nmi_error(const struct
>> cpu_user_regs *regs, unsigned char re
>> console_force_unlock();
>> printk("Uhhuh. NMI received for unknown reason %02x.\n",
>> reason);
>> printk("Do you have a strange power saving mode enabled?\n");
>> - fatal_trap(TRAP_nmi, regs);
>> + fatal_trap(regs);
>> }
>> }
>> diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
>> index a3ed216..42835d0 100644
>> --- a/xen/arch/x86/x86_64/entry.S
>> +++ b/xen/arch/x86/x86_64/entry.S
>> @@ -536,8 +536,7 @@ exception_with_ints_disabled:
>> /* No special register assumptions. */
>> FATAL_exception_with_ints_disabled:
>> - movzbl UREGS_entry_vector(%rsp),%edi
>> - movq %rsp,%rsi
>> + movq %rsp,%rdi
>> call fatal_trap
>> ud2
>> diff --git a/xen/include/asm-x86/processor.h
>> b/xen/include/asm-x86/processor.h
>> index a156e01..9e1f210 100644
>> --- a/xen/include/asm-x86/processor.h
>> +++ b/xen/include/asm-x86/processor.h
>> @@ -481,7 +481,7 @@ void show_registers(const struct cpu_user_regs
>> *regs);
>> void show_execution_state(const struct cpu_user_regs *regs);
>> #define dump_execution_state()
>> run_in_exception_handler(show_execution_state)
>> void show_page_walk(unsigned long addr);
>> -void noreturn fatal_trap(int trapnr, const struct cpu_user_regs *regs);
>> +void noreturn fatal_trap(const struct cpu_user_regs *regs);
>> void compat_show_guest_stack(struct vcpu *v,
>> const struct cpu_user_regs *regs, int
>> lines);
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] x86/traps: Remove redundant trapnr parameter from fatal_trap()
2014-09-01 16:27 ` Andrew Cooper
@ 2014-09-07 0:18 ` Don Slutz
0 siblings, 0 replies; 4+ messages in thread
From: Don Slutz @ 2014-09-07 0:18 UTC (permalink / raw)
To: Andrew Cooper; +Cc: Jan Beulich, Don Slutz, Xen-devel
On 09/01/14 12:27, Andrew Cooper wrote:
> On 01/09/14 17:10, Don Slutz wrote:
>> On 09/01/14 06:06, Andrew Cooper wrote:
>>> It is always available via regs->entry_vector.
>>>
>>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>>> CC: Jan Beulich <JBeulich@suse.com>
>>> ---
>>> -void fatal_trap(int trapnr, const struct cpu_user_regs *regs)
>>> +void fatal_trap(const struct cpu_user_regs *regs)
>>> {
>>> static DEFINE_PER_CPU(char, depth);
>>> + unsigned int trapnr = regs->entry_vector;
>> Should this be:
>>
>> unsigned int trapnr = regs->entry_vector &
>> ~(TRAP_regs_partial|TRAP_syscall);
>>
>>
>> To get rid of the extra bits?
>>
>> -Don Slutz
> No; I don't think so. There should be no paths into fatal_trap() which
> would set these bits, as these bits are only set as a result of guest
> sys/hypercall interaction, while fatal_trap() is a terminal error condition.
>
> Furthermore, if a path is discovered then a) it will be more obvious
> from the error message and b) we probably have a security problem to fix.
>
> ~Andrew
Ok.
Reviewed-by: Don Slutz <dslutz@verizon.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-09-07 0:18 UTC | newest]
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2014-09-01 10:06 [PATCH] x86/traps: Remove redundant trapnr parameter from fatal_trap() Andrew Cooper
2014-09-01 16:10 ` Don Slutz
2014-09-01 16:27 ` Andrew Cooper
2014-09-07 0:18 ` Don Slutz
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