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* [PATCH v1 1/4] powerpc: Remove probe_user_read_inst()
@ 2021-04-12 11:42 ` Christophe Leroy
  0 siblings, 0 replies; 11+ messages in thread
From: Christophe Leroy @ 2021-04-12 11:42 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, jniethe5
  Cc: linux-kernel, linuxppc-dev

Its name comes from former probe_user_read() function.
That function is now called copy_from_user_nofault().

probe_user_read_inst() uses copy_from_user_nofault() to read only
a few bytes. It is suboptimal.

It does the same as get_user_inst() but in addition disables
page faults.

But on the other hand, it is not used for the time being. So remove it
for now. If one day it is really needed, we can give it a new name
more in line with today's naming, and implement it using get_user_inst()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/inst.h |  3 ---
 arch/powerpc/lib/inst.c         | 31 -------------------------------
 2 files changed, 34 deletions(-)

diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index 19e18af2fac9..2902d4e6a363 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -175,9 +175,6 @@ static inline char *__ppc_inst_as_str(char str[PPC_INST_STR_LEN], struct ppc_ins
 	__str;				\
 })
 
-int probe_user_read_inst(struct ppc_inst *inst,
-			 struct ppc_inst __user *nip);
-
 int probe_kernel_read_inst(struct ppc_inst *inst,
 			   struct ppc_inst *src);
 
diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c
index 9cc17eb62462..c57b3548de37 100644
--- a/arch/powerpc/lib/inst.c
+++ b/arch/powerpc/lib/inst.c
@@ -9,24 +9,6 @@
 #include <asm/ppc-opcode.h>
 
 #ifdef CONFIG_PPC64
-int probe_user_read_inst(struct ppc_inst *inst,
-			 struct ppc_inst __user *nip)
-{
-	unsigned int val, suffix;
-	int err;
-
-	err = copy_from_user_nofault(&val, nip, sizeof(val));
-	if (err)
-		return err;
-	if (get_op(val) == OP_PREFIX) {
-		err = copy_from_user_nofault(&suffix, (void __user *)nip + 4, 4);
-		*inst = ppc_inst_prefix(val, suffix);
-	} else {
-		*inst = ppc_inst(val);
-	}
-	return err;
-}
-
 int probe_kernel_read_inst(struct ppc_inst *inst,
 			   struct ppc_inst *src)
 {
@@ -45,19 +27,6 @@ int probe_kernel_read_inst(struct ppc_inst *inst,
 	return err;
 }
 #else /* !CONFIG_PPC64 */
-int probe_user_read_inst(struct ppc_inst *inst,
-			 struct ppc_inst __user *nip)
-{
-	unsigned int val;
-	int err;
-
-	err = copy_from_user_nofault(&val, nip, sizeof(val));
-	if (!err)
-		*inst = ppc_inst(val);
-
-	return err;
-}
-
 int probe_kernel_read_inst(struct ppc_inst *inst,
 			   struct ppc_inst *src)
 {
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2021-04-12 19:43 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-12 11:42 [PATCH v1 1/4] powerpc: Remove probe_user_read_inst() Christophe Leroy
2021-04-12 11:42 ` Christophe Leroy
2021-04-12 11:42 ` [PATCH v1 2/4] powerpc: Make probe_kernel_read_inst() common to PPC32 and PPC64 Christophe Leroy
2021-04-12 11:42   ` Christophe Leroy
2021-04-12 11:42 ` [PATCH v1 3/4] powerpc: Rename probe_kernel_read_inst() Christophe Leroy
2021-04-12 11:42   ` Christophe Leroy
2021-04-12 11:42 ` [PATCH v1 4/4] powerpc: Move copy_from_kernel_nofault_inst() Christophe Leroy
2021-04-12 11:42   ` Christophe Leroy
2021-04-12 19:41   ` kernel test robot
2021-04-12 19:41     ` kernel test robot
2021-04-12 19:41     ` kernel test robot

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