Re: [PATCH v2 2/2] powerpc: use probe_user_read()
On Tue, 2019-01-08 at 10:37 +0100, Christophe Leroy wrote:
> Hi Michael and Russell,
>
> Any idea why:
> - checkpatch reports missing Signed-off-by:
> - Snowpatch build fails on PPC64 (it seems unrelated to the patch,
> something wrong in lib/genalloc.c)
Upstream kernel broke for powerpc (snowpatch applies patches on top of
powerpc/next), it was fixed in commit
35004f2e55807a1a1491db24ab512dd2f770a130 which I believe is in
powerpc/next now. I will look at rerunning tests for all the patches
that this impacted.
As for the S-o-b, no clue, I'll have a look. Thanks for the report!
- Russell
>
> Thanks
> Christophe
>
> Le 08/01/2019 à 08:37, Christophe Leroy a écrit :
> > Instead of opencoding, use probe_user_read() to failessly
> > read a user location.
> >
> > Signed-off-by: Christophe Leroy
> > ---
> > v2: Using probe_user_read() instead of probe_user_address()
> >
> > arch/powerpc/kernel/process.c | 12 +---
> > arch/powerpc/mm/fault.c | 6 +-
> > arch/powerpc/perf/callchain.c | 20 +++-
> > arch/powerpc/perf/core-book3s.c | 8 +---
> > arch/powerpc/sysdev/fsl_pci.c | 10 --
> > 5 files changed, 10 insertions(+), 46 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/process.c
> > b/arch/powerpc/kernel/process.c
> > index ce393df243aa..6a4b59d574c2 100644
> > --- a/arch/powerpc/kernel/process.c
> > +++ b/arch/powerpc/kernel/process.c
> > @@ -1298,16 +1298,6 @@ void show_user_instructions(struct pt_regs
> > *regs)
> >
> > pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
> >
> > - /*
> > -* Make sure the NIP points at userspace, not kernel text/data
> > or
> > -* elsewhere.
> > -*/
> > - if (!__access_ok(pc, NR_INSN_TO_PRINT * sizeof(int), USER_DS))
> > {
> > - pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
> > - current->comm, current->pid);
> > - return;
> > - }
> > -
> > seq_buf_init(, buf, sizeof(buf));
> >
> > while (n) {
> > @@ -1318,7 +1308,7 @@ void show_user_instructions(struct pt_regs
> > *regs)
> > for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
> > int instr;
> >
> > - if (probe_kernel_address((const void *)pc,
> > instr)) {
> > + if (probe_user_read(, (void __user *)pc,
> > sizeof(instr))) {
> > seq_buf_printf(, " ");
> > continue;
> > }
> > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> > index 887f11bcf330..ec74305fa330 100644
> > --- a/arch/powerpc/mm/fault.c
> > +++ b/arch/powerpc/mm/fault.c
> > @@ -276,12 +276,8 @@ static bool bad_stack_expansion(struct pt_regs
> > *regs, unsigned long address,
> > if ((flags & FAULT_FLAG_WRITE) && (flags &
> > FAULT_FLAG_USER) &&
> > access_ok(nip, sizeof(*nip))) {
> > unsigned int inst;
> > - int res;
> >
> > - pagefault_disable();
> > - res = __get_user_inatomic(inst, nip);
> > - pagefault_enable();
> > - if (!res)
> > + if (!probe_user_read(, nip, sizeof(inst)))
> > return !store_updates_sp(inst);
> > *must_retry = true;
> > }
> > diff --git a/arch/powerpc/perf/callchain.c
> > b/arch/powerpc/perf/callchain.c
> > index 0af051a1974e..0680efb2237b 100644
> > --- a/arch/powerpc/perf/callchain.c
> > +++ b/arch/powerpc/perf/callchain.c
> > @@ -159,12 +159,8 @@ static int read_user_stack_64(unsigned long
> > __user *ptr, unsigned long *ret)
> > ((unsigned long)ptr & 7))
> > return -EFAULT;
> >
> > - pagefault_disable();
> > - if (!__get_user_inatomic(*ret, ptr)) {
> > - pagefault_enable();
> > + if (!probe_user_read(ret, ptr, sizeof(*ret)))
> > return 0;
> > - }
> > - pagefault_enable();
> >
> > return read_user_stack_slow(ptr, ret, 8);
> > }
> > @@ -175,12 +171,8 @@ static int read_user_stack_32(unsigned int
> > __user *ptr, unsigned int *ret)
> > ((unsigned long)ptr & 3))
> > return -EFAULT;
> >
> > - pagefault_disable();
> > - if (!__get_user_inatomic(*ret, ptr)) {
> > - pagefault_enable();
> > + if (!probe_user_read(ret, ptr, sizeof(*ret)))
> > return 0;
> > - }
> > - pagefault_enable();
> >
> > return read_user_stack_slow(ptr, ret, 4);
> > }
> > @@ -307,17 +299,11 @@ static inline int current_is_64bit(void)
> >*/
> > static int read_user_stack_32(unsigned int __user *ptr, unsigned
> > int *ret)
> > {
> > - int rc;
> > -
> > if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
> > ((unsigned long)ptr & 3))
> > return -EFAULT;
> >
> > - pagefault_disable();
> > - rc = __get_user_inatomic(*ret, ptr);
> > -
Re: [PATCH v2 2/2] powerpc: use probe_user_read()
Hi Michael and Russell,
Any idea why:
- checkpatch reports missing Signed-off-by:
- Snowpatch build fails on PPC64 (it seems unrelated to the patch,
something wrong in lib/genalloc.c)
Thanks
Christophe
Le 08/01/2019 à 08:37, Christophe Leroy a écrit :
Instead of opencoding, use probe_user_read() to failessly
read a user location.
Signed-off-by: Christophe Leroy
---
v2: Using probe_user_read() instead of probe_user_address()
arch/powerpc/kernel/process.c | 12 +---
arch/powerpc/mm/fault.c | 6 +-
arch/powerpc/perf/callchain.c | 20 +++-
arch/powerpc/perf/core-book3s.c | 8 +---
arch/powerpc/sysdev/fsl_pci.c | 10 --
5 files changed, 10 insertions(+), 46 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ce393df243aa..6a4b59d574c2 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1298,16 +1298,6 @@ void show_user_instructions(struct pt_regs *regs)
pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
- /*
-* Make sure the NIP points at userspace, not kernel text/data or
-* elsewhere.
-*/
- if (!__access_ok(pc, NR_INSN_TO_PRINT * sizeof(int), USER_DS)) {
- pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
- current->comm, current->pid);
- return;
- }
-
seq_buf_init(, buf, sizeof(buf));
while (n) {
@@ -1318,7 +1308,7 @@ void show_user_instructions(struct pt_regs *regs)
for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
int instr;
- if (probe_kernel_address((const void *)pc, instr)) {
+ if (probe_user_read(, (void __user *)pc,
sizeof(instr))) {
seq_buf_printf(, " ");
continue;
}
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 887f11bcf330..ec74305fa330 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -276,12 +276,8 @@ static bool bad_stack_expansion(struct pt_regs *regs,
unsigned long address,
if ((flags & FAULT_FLAG_WRITE) && (flags & FAULT_FLAG_USER) &&
access_ok(nip, sizeof(*nip))) {
unsigned int inst;
- int res;
- pagefault_disable();
- res = __get_user_inatomic(inst, nip);
- pagefault_enable();
- if (!res)
+ if (!probe_user_read(, nip, sizeof(inst)))
return !store_updates_sp(inst);
*must_retry = true;
}
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index 0af051a1974e..0680efb2237b 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -159,12 +159,8 @@ static int read_user_stack_64(unsigned long __user *ptr,
unsigned long *ret)
((unsigned long)ptr & 7))
return -EFAULT;
- pagefault_disable();
- if (!__get_user_inatomic(*ret, ptr)) {
- pagefault_enable();
+ if (!probe_user_read(ret, ptr, sizeof(*ret)))
return 0;
- }
- pagefault_enable();
return read_user_stack_slow(ptr, ret, 8);
}
@@ -175,12 +171,8 @@ static int read_user_stack_32(unsigned int __user *ptr,
unsigned int *ret)
((unsigned long)ptr & 3))
return -EFAULT;
- pagefault_disable();
- if (!__get_user_inatomic(*ret, ptr)) {
- pagefault_enable();
+ if (!probe_user_read(ret, ptr, sizeof(*ret)))
return 0;
- }
- pagefault_enable();
return read_user_stack_slow(ptr, ret, 4);
}
@@ -307,17 +299,11 @@ static inline int current_is_64bit(void)
*/
static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
{
- int rc;
-
if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
((unsigned long)ptr & 3))
return -EFAULT;
- pagefault_disable();
- rc = __get_user_inatomic(*ret, ptr);
- pagefault_enable();
-
- return rc;
+ return probe_user_read(ret, ptr, sizeof(*ret));
}
static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index b0723002a396..4b64ddf0db68 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -416,7 +416,6 @@ static void power_pmu_sched_task(struct perf_event_context
*ctx, bool sched_in)
static __u64 power_pmu_bhrb_to(u64 addr)
{
unsigned int instr;
- int ret;
__u64 target;
if (is_kernel_addr(addr)) {
@@ -427,13 +426,8 @@ static __u64 power_pmu_bhrb_to(u64 addr)
}
/* Userspace: need copy instruction here
Re: [PATCH v2 2/2] powerpc: use probe_user_read()
Le 08/01/2019 à 10:04, David Hildenbrand a écrit :
On 08.01.19 08:37, Christophe Leroy wrote:
Instead of opencoding, use probe_user_read() to failessly
read a user location.
Signed-off-by: Christophe Leroy
---
v2: Using probe_user_read() instead of probe_user_address()
arch/powerpc/kernel/process.c | 12 +---
arch/powerpc/mm/fault.c | 6 +-
arch/powerpc/perf/callchain.c | 20 +++-
arch/powerpc/perf/core-book3s.c | 8 +---
arch/powerpc/sysdev/fsl_pci.c | 10 --
5 files changed, 10 insertions(+), 46 deletions(-)
[snip]
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 918be816b097..c8a1b26489f5 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -1068,13 +1068,11 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
addr += mfspr(SPRN_MCAR);
if (is_in_pci_mem_space(addr)) {
- if (user_mode(regs)) {
- pagefault_disable();
- ret = get_user(inst, (__u32 __user *)regs->nip);
- pagefault_enable();
- } else {
+ if (user_mode(regs))
+ ret = probe_user_read(, (void __user *)regs->nip,
+ sizeof(inst));
What about also adding probe_user_address ?
Michael doesn't like it, see https://patchwork.ozlabs.org/patch/1007117/
Christophe
+ else
ret = probe_kernel_address((void *)regs->nip, inst);
- }
if (!ret && mcheck_handle_load(regs, inst)) {
regs->nip += 4;
Re: [PATCH v2 2/2] powerpc: use probe_user_read()
On 08.01.19 08:37, Christophe Leroy wrote:
> Instead of opencoding, use probe_user_read() to failessly
> read a user location.
>
> Signed-off-by: Christophe Leroy
> ---
> v2: Using probe_user_read() instead of probe_user_address()
>
> arch/powerpc/kernel/process.c | 12 +---
> arch/powerpc/mm/fault.c | 6 +-
> arch/powerpc/perf/callchain.c | 20 +++-
> arch/powerpc/perf/core-book3s.c | 8 +---
> arch/powerpc/sysdev/fsl_pci.c | 10 --
> 5 files changed, 10 insertions(+), 46 deletions(-)
>
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index ce393df243aa..6a4b59d574c2 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -1298,16 +1298,6 @@ void show_user_instructions(struct pt_regs *regs)
>
> pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
>
> - /*
> - * Make sure the NIP points at userspace, not kernel text/data or
> - * elsewhere.
> - */
> - if (!__access_ok(pc, NR_INSN_TO_PRINT * sizeof(int), USER_DS)) {
> - pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
> - current->comm, current->pid);
> - return;
> - }
> -
> seq_buf_init(, buf, sizeof(buf));
>
> while (n) {
> @@ -1318,7 +1308,7 @@ void show_user_instructions(struct pt_regs *regs)
> for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
> int instr;
>
> - if (probe_kernel_address((const void *)pc, instr)) {
> + if (probe_user_read(, (void __user *)pc,
> sizeof(instr))) {
> seq_buf_printf(, " ");
> continue;
> }
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index 887f11bcf330..ec74305fa330 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -276,12 +276,8 @@ static bool bad_stack_expansion(struct pt_regs *regs,
> unsigned long address,
> if ((flags & FAULT_FLAG_WRITE) && (flags & FAULT_FLAG_USER) &&
> access_ok(nip, sizeof(*nip))) {
> unsigned int inst;
> - int res;
>
> - pagefault_disable();
> - res = __get_user_inatomic(inst, nip);
> - pagefault_enable();
> - if (!res)
> + if (!probe_user_read(, nip, sizeof(inst)))
> return !store_updates_sp(inst);
> *must_retry = true;
> }
> diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
> index 0af051a1974e..0680efb2237b 100644
> --- a/arch/powerpc/perf/callchain.c
> +++ b/arch/powerpc/perf/callchain.c
> @@ -159,12 +159,8 @@ static int read_user_stack_64(unsigned long __user *ptr,
> unsigned long *ret)
> ((unsigned long)ptr & 7))
> return -EFAULT;
>
> - pagefault_disable();
> - if (!__get_user_inatomic(*ret, ptr)) {
> - pagefault_enable();
> + if (!probe_user_read(ret, ptr, sizeof(*ret)))
> return 0;
> - }
> - pagefault_enable();
>
> return read_user_stack_slow(ptr, ret, 8);
> }
> @@ -175,12 +171,8 @@ static int read_user_stack_32(unsigned int __user *ptr,
> unsigned int *ret)
> ((unsigned long)ptr & 3))
> return -EFAULT;
>
> - pagefault_disable();
> - if (!__get_user_inatomic(*ret, ptr)) {
> - pagefault_enable();
> + if (!probe_user_read(ret, ptr, sizeof(*ret)))
> return 0;
> - }
> - pagefault_enable();
>
> return read_user_stack_slow(ptr, ret, 4);
> }
> @@ -307,17 +299,11 @@ static inline int current_is_64bit(void)
> */
> static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
> {
> - int rc;
> -
> if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
> ((unsigned long)ptr & 3))
> return -EFAULT;
>
> - pagefault_disable();
> - rc = __get_user_inatomic(*ret, ptr);
> - pagefault_enable();
> -
> - return rc;
> + return probe_user_read(ret, ptr, sizeof(*ret));
> }
>
> static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx
> *entry,
> diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
> index b0723002a396..4b64ddf0db68 100644
> --- a/arch/powerpc/perf/core-book3s.c
> +++ b/arch/powerpc/perf/core-book3s.c
> @@ -416,7 +416,6 @@ static void power_pmu_sched_task(struct
> perf_event_context *ctx, bool sched_in)
> static __u64 power_pmu_bhrb_to(u64 addr)
> {
> unsigned int instr;
> - int ret;
> __u64 target;
>
> if (is_kernel_addr(addr)) {
> @@ -427,13 +426,8 @@ static __u64 power_pmu_bhrb_to(u64 addr)
> }
>
> /* Userspace: need copy instruction here then translate it */
>
[PATCH v2 2/2] powerpc: use probe_user_read()
Instead of opencoding, use probe_user_read() to failessly
read a user location.
Signed-off-by: Christophe Leroy
---
v2: Using probe_user_read() instead of probe_user_address()
arch/powerpc/kernel/process.c | 12 +---
arch/powerpc/mm/fault.c | 6 +-
arch/powerpc/perf/callchain.c | 20 +++-
arch/powerpc/perf/core-book3s.c | 8 +---
arch/powerpc/sysdev/fsl_pci.c | 10 --
5 files changed, 10 insertions(+), 46 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ce393df243aa..6a4b59d574c2 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1298,16 +1298,6 @@ void show_user_instructions(struct pt_regs *regs)
pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
- /*
-* Make sure the NIP points at userspace, not kernel text/data or
-* elsewhere.
-*/
- if (!__access_ok(pc, NR_INSN_TO_PRINT * sizeof(int), USER_DS)) {
- pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
- current->comm, current->pid);
- return;
- }
-
seq_buf_init(, buf, sizeof(buf));
while (n) {
@@ -1318,7 +1308,7 @@ void show_user_instructions(struct pt_regs *regs)
for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
int instr;
- if (probe_kernel_address((const void *)pc, instr)) {
+ if (probe_user_read(, (void __user *)pc,
sizeof(instr))) {
seq_buf_printf(, " ");
continue;
}
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 887f11bcf330..ec74305fa330 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -276,12 +276,8 @@ static bool bad_stack_expansion(struct pt_regs *regs,
unsigned long address,
if ((flags & FAULT_FLAG_WRITE) && (flags & FAULT_FLAG_USER) &&
access_ok(nip, sizeof(*nip))) {
unsigned int inst;
- int res;
- pagefault_disable();
- res = __get_user_inatomic(inst, nip);
- pagefault_enable();
- if (!res)
+ if (!probe_user_read(, nip, sizeof(inst)))
return !store_updates_sp(inst);
*must_retry = true;
}
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index 0af051a1974e..0680efb2237b 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -159,12 +159,8 @@ static int read_user_stack_64(unsigned long __user *ptr,
unsigned long *ret)
((unsigned long)ptr & 7))
return -EFAULT;
- pagefault_disable();
- if (!__get_user_inatomic(*ret, ptr)) {
- pagefault_enable();
+ if (!probe_user_read(ret, ptr, sizeof(*ret)))
return 0;
- }
- pagefault_enable();
return read_user_stack_slow(ptr, ret, 8);
}
@@ -175,12 +171,8 @@ static int read_user_stack_32(unsigned int __user *ptr,
unsigned int *ret)
((unsigned long)ptr & 3))
return -EFAULT;
- pagefault_disable();
- if (!__get_user_inatomic(*ret, ptr)) {
- pagefault_enable();
+ if (!probe_user_read(ret, ptr, sizeof(*ret)))
return 0;
- }
- pagefault_enable();
return read_user_stack_slow(ptr, ret, 4);
}
@@ -307,17 +299,11 @@ static inline int current_is_64bit(void)
*/
static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
{
- int rc;
-
if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
((unsigned long)ptr & 3))
return -EFAULT;
- pagefault_disable();
- rc = __get_user_inatomic(*ret, ptr);
- pagefault_enable();
-
- return rc;
+ return probe_user_read(ret, ptr, sizeof(*ret));
}
static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx
*entry,
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index b0723002a396..4b64ddf0db68 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -416,7 +416,6 @@ static void power_pmu_sched_task(struct perf_event_context
*ctx, bool sched_in)
static __u64 power_pmu_bhrb_to(u64 addr)
{
unsigned int instr;
- int ret;
__u64 target;
if (is_kernel_addr(addr)) {
@@ -427,13 +426,8 @@ static __u64 power_pmu_bhrb_to(u64 addr)
}
/* Userspace: need copy instruction here then translate it */
- pagefault_disable();
- ret = __get_user_inatomic(instr, (unsigned int __user *)addr);
- if (ret) {
- pagefault_enable();
+ if
