diff options
| author | Jordan Niethe <jniethe5@gmail.com> | 2020-05-06 13:40:33 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-19 00:10:37 +1000 |
| commit | 7ba68b2172c19031fdc2a2caf37328edd146e299 (patch) | |
| tree | 308fb5c5231ef35c900818c159b58b7410cb3d18 | |
| parent | f8faaffaa7d99028e457ef2d1dcb43a98f736938 (diff) | |
powerpc: Add a probe_user_read_inst() function
Introduce a probe_user_read_inst() function to use in cases where
probe_user_read() is used for getting an instruction. This will be
more useful for prefixed instructions.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
[mpe: Don't write to *inst on error, fold in __user annotations]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-14-jniethe5@gmail.com
| -rw-r--r-- | arch/powerpc/include/asm/inst.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/lib/inst.c | 20 | ||||
| -rw-r--r-- | arch/powerpc/mm/fault.c | 4 |
4 files changed, 26 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h index f9cbb24d2e34..4db0ecee2698 100644 --- a/arch/powerpc/include/asm/inst.h +++ b/arch/powerpc/include/asm/inst.h @@ -37,4 +37,7 @@ static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y) return ppc_inst_val(x) == ppc_inst_val(y); } +int probe_user_read_inst(struct ppc_inst *inst, + struct ppc_inst __user *nip); + #endif /* _ASM_POWERPC_INST_H */ diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index b8de3be10eb4..546591848219 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -16,7 +16,7 @@ CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING endif -obj-y += alloc.o code-patching.o feature-fixups.o pmem.o +obj-y += alloc.o code-patching.o feature-fixups.o pmem.o inst.o ifndef CONFIG_KASAN obj-y += string.o memcmp_$(BITS).o diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c new file mode 100644 index 000000000000..605220dbb6ba --- /dev/null +++ b/arch/powerpc/lib/inst.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2020, IBM Corporation. + */ + +#include <linux/uaccess.h> +#include <asm/inst.h> + +int probe_user_read_inst(struct ppc_inst *inst, + struct ppc_inst __user *nip) +{ + unsigned int val; + int err; + + err = probe_user_read(&val, nip, sizeof(val)); + if (!err) + *inst = ppc_inst(val); + + return err; +} diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 4f0ef68a7d31..2393ed9d84bb 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -282,7 +282,7 @@ static bool bad_stack_expansion(struct pt_regs *regs, unsigned long address, * expand to 1MB without further checks. */ if (address + 0x100000 < vma->vm_end) { - unsigned int __user *nip = (unsigned int __user *)regs->nip; + struct ppc_inst __user *nip = (struct ppc_inst __user *)regs->nip; /* get user regs even if this fault is in kernel mode */ struct pt_regs *uregs = current->thread.regs; if (uregs == NULL) @@ -307,7 +307,7 @@ static bool bad_stack_expansion(struct pt_regs *regs, unsigned long address, access_ok(nip, sizeof(*nip))) { struct ppc_inst inst; - if (!probe_user_read(&inst, nip, sizeof(inst))) + if (!probe_user_read_inst(&inst, nip)) return !store_updates_sp(inst); *must_retry = true; } |