Re: [PATCH v2 2/2] powerpc: use probe_user_read()
From: Christophe Leroy
Date: Tue Jan 08 2019 - 04:19:37 EST
Le 08/01/2019 Ã 10:04, David Hildenbrand a ÃcritÂ:
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 <christophe.leroy@xxxxxx>
---
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(&inst, (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;