The patch titled
Subject: powerpc: use probe_user_read()
has been added to the -mm tree. Its filename is
powerpc-use-probe_user_read.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/powerpc-use-probe_user_read.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/powerpc-use-probe_user_read.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Christophe Leroy <christophe.leroy@xxxxxx>
Subject: powerpc: use probe_user_read()
Instead of opencoding, use probe_user_read() to failessly read a user
location.
Link: http://lkml.kernel.org/r/afd95fa4747f1c1eb66677025c2c7c9055f43cce.1547652372.git.christophe.leroy@xxxxxx
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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(-)
--- a/arch/powerpc/kernel/process.c~powerpc-use-probe_user_read
+++ a/arch/powerpc/kernel/process.c
@@ -1298,16 +1298,6 @@ void show_user_instructions(struct pt_re
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(&s, buf, sizeof(buf));
while (n) {
@@ -1318,7 +1308,7 @@ void show_user_instructions(struct pt_re
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(&instr, (void __user *)pc, sizeof(instr))) {
seq_buf_printf(&s, "XXXXXXXX ");
continue;
}
--- a/arch/powerpc/mm/fault.c~powerpc-use-probe_user_read
+++ a/arch/powerpc/mm/fault.c
@@ -276,12 +276,8 @@ static bool bad_stack_expansion(struct p
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(&inst, nip, sizeof(inst)))
return !store_updates_sp(inst);
*must_retry = true;
}
--- a/arch/powerpc/perf/callchain.c~powerpc-use-probe_user_read
+++ a/arch/powerpc/perf/callchain.c
@@ -159,12 +159,8 @@ static int read_user_stack_64(unsigned l
((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 i
((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,
--- a/arch/powerpc/perf/core-book3s.c~powerpc-use-probe_user_read
+++ a/arch/powerpc/perf/core-book3s.c
@@ -416,7 +416,6 @@ static void power_pmu_sched_task(struct
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 (probe_user_read(&instr, (unsigned int __user *)addr, sizeof(instr)))
return 0;
- }
- pagefault_enable();
target = branch_target(&instr);
if ((!target) || (instr & BRANCH_ABSOLUTE))
--- a/arch/powerpc/sysdev/fsl_pci.c~powerpc-use-probe_user_read
+++ a/arch/powerpc/sysdev/fsl_pci.c
@@ -1068,13 +1068,11 @@ int fsl_pci_mcheck_exception(struct pt_r
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(&inst, (void __user *)regs->nip,
+ sizeof(inst));
+ else
ret = probe_kernel_address((void *)regs->nip, inst);
- }
if (!ret && mcheck_handle_load(regs, inst)) {
regs->nip += 4;
_
Patches currently in -mm which might be from christophe.leroy@xxxxxx are
mm-add-probe_user_read.patch
powerpc-use-probe_user_read.patch
powerpc-use-memblock-functions-returning-virtual-address.patch
