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From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	naveen.n.rao@linux.vnet.ibm.com, jniethe5@gmail.com
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2 07/12] powerpc/lib/code-patching: Don't use struct 'ppc_inst' for runnable code in tests.
Date: Thu, 20 May 2021 13:50:44 +0000 (UTC)	[thread overview]
Message-ID: <d8425fb42a4adebc35b7509f121817eeb02fac31.1621516826.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1621516826.git.christophe.leroy@csgroup.eu>

'struct ppc_inst' is meant to represent an instruction internally, it
is not meant to dereference code in memory.

For testing code patching, use patch_instruction() to properly
write into memory the code to be tested.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/lib/code-patching.c | 95 ++++++++++++++++++--------------
 1 file changed, 53 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 82f2c1edb498..508e9511ca96 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -422,9 +422,9 @@ static void __init test_branch_iform(void)
 {
 	int err;
 	struct ppc_inst instr;
-	unsigned long addr;
-
-	addr = (unsigned long)&instr;
+	unsigned int tmp[2];
+	struct ppc_inst *iptr = (struct ppc_inst *)tmp;
+	unsigned long addr = (unsigned long)tmp;
 
 	/* The simplest case, branch to self, no flags */
 	check(instr_is_branch_iform(ppc_inst(0x48000000)));
@@ -445,52 +445,57 @@ static void __init test_branch_iform(void)
 	check(!instr_is_branch_iform(ppc_inst(0x7bfffffd)));
 
 	/* Absolute branch to 0x100 */
-	instr = ppc_inst(0x48000103);
-	check(instr_is_branch_to_addr(&instr, 0x100));
+	patch_instruction(iptr, ppc_inst(0x48000103));
+	check(instr_is_branch_to_addr(iptr, 0x100));
 	/* Absolute branch to 0x420fc */
-	instr = ppc_inst(0x480420ff);
-	check(instr_is_branch_to_addr(&instr, 0x420fc));
+	patch_instruction(iptr, ppc_inst(0x480420ff));
+	check(instr_is_branch_to_addr(iptr, 0x420fc));
 	/* Maximum positive relative branch, + 20MB - 4B */
-	instr = ppc_inst(0x49fffffc);
-	check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC));
+	patch_instruction(iptr, ppc_inst(0x49fffffc));
+	check(instr_is_branch_to_addr(iptr, addr + 0x1FFFFFC));
 	/* Smallest negative relative branch, - 4B */
-	instr = ppc_inst(0x4bfffffc);
-	check(instr_is_branch_to_addr(&instr, addr - 4));
+	patch_instruction(iptr, ppc_inst(0x4bfffffc));
+	check(instr_is_branch_to_addr(iptr, addr - 4));
 	/* Largest negative relative branch, - 32 MB */
-	instr = ppc_inst(0x4a000000);
-	check(instr_is_branch_to_addr(&instr, addr - 0x2000000));
+	patch_instruction(iptr, ppc_inst(0x4a000000));
+	check(instr_is_branch_to_addr(iptr, addr - 0x2000000));
 
 	/* Branch to self, with link */
-	err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK);
-	check(instr_is_branch_to_addr(&instr, addr));
+	err = create_branch(&instr, iptr, addr, BRANCH_SET_LINK);
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr));
 
 	/* Branch to self - 0x100, with link */
-	err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK);
-	check(instr_is_branch_to_addr(&instr, addr - 0x100));
+	err = create_branch(&instr, iptr, addr - 0x100, BRANCH_SET_LINK);
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr - 0x100));
 
 	/* Branch to self + 0x100, no link */
-	err = create_branch(&instr, &instr, addr + 0x100, 0);
-	check(instr_is_branch_to_addr(&instr, addr + 0x100));
+	err = create_branch(&instr, iptr, addr + 0x100, 0);
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr + 0x100));
 
 	/* Maximum relative negative offset, - 32 MB */
-	err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK);
-	check(instr_is_branch_to_addr(&instr, addr - 0x2000000));
+	err = create_branch(&instr, iptr, addr - 0x2000000, BRANCH_SET_LINK);
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr - 0x2000000));
 
 	/* Out of range relative negative offset, - 32 MB + 4*/
-	err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK);
+	err = create_branch(&instr, iptr, addr - 0x2000004, BRANCH_SET_LINK);
 	check(err);
 
 	/* Out of range relative positive offset, + 32 MB */
-	err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK);
+	err = create_branch(&instr, iptr, addr + 0x2000000, BRANCH_SET_LINK);
 	check(err);
 
 	/* Unaligned target */
-	err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK);
+	err = create_branch(&instr, iptr, addr + 3, BRANCH_SET_LINK);
 	check(err);
 
 	/* Check flags are masked correctly */
-	err = create_branch(&instr, &instr, addr, 0xFFFFFFFC);
-	check(instr_is_branch_to_addr(&instr, addr));
+	err = create_branch(&instr, iptr, addr, 0xFFFFFFFC);
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr));
 	check(ppc_inst_equal(instr, ppc_inst(0x48000000)));
 }
 
@@ -513,9 +518,10 @@ static void __init test_branch_bform(void)
 	int err;
 	unsigned long addr;
 	struct ppc_inst *iptr, instr;
+	unsigned int tmp[2];
 	unsigned int flags;
 
-	iptr = &instr;
+	iptr = (struct ppc_inst *)tmp;
 	addr = (unsigned long)iptr;
 
 	/* The simplest case, branch to self, no flags */
@@ -528,39 +534,43 @@ static void __init test_branch_bform(void)
 	check(!instr_is_branch_bform(ppc_inst(0x7bffffff)));
 
 	/* Absolute conditional branch to 0x100 */
-	instr = ppc_inst(0x43ff0103);
-	check(instr_is_branch_to_addr(&instr, 0x100));
+	patch_instruction(iptr, ppc_inst(0x43ff0103));
+	check(instr_is_branch_to_addr(iptr, 0x100));
 	/* Absolute conditional branch to 0x20fc */
-	instr = ppc_inst(0x43ff20ff);
-	check(instr_is_branch_to_addr(&instr, 0x20fc));
+	patch_instruction(iptr, ppc_inst(0x43ff20ff));
+	check(instr_is_branch_to_addr(iptr, 0x20fc));
 	/* Maximum positive relative conditional branch, + 32 KB - 4B */
-	instr = ppc_inst(0x43ff7ffc);
-	check(instr_is_branch_to_addr(&instr, addr + 0x7FFC));
+	patch_instruction(iptr, ppc_inst(0x43ff7ffc));
+	check(instr_is_branch_to_addr(iptr, addr + 0x7FFC));
 	/* Smallest negative relative conditional branch, - 4B */
-	instr = ppc_inst(0x43fffffc);
-	check(instr_is_branch_to_addr(&instr, addr - 4));
+	patch_instruction(iptr, ppc_inst(0x43fffffc));
+	check(instr_is_branch_to_addr(iptr, addr - 4));
 	/* Largest negative relative conditional branch, - 32 KB */
-	instr = ppc_inst(0x43ff8000);
-	check(instr_is_branch_to_addr(&instr, addr - 0x8000));
+	patch_instruction(iptr, ppc_inst(0x43ff8000));
+	check(instr_is_branch_to_addr(iptr, addr - 0x8000));
 
 	/* All condition code bits set & link */
 	flags = 0x3ff000 | BRANCH_SET_LINK;
 
 	/* Branch to self */
 	err = create_cond_branch(&instr, iptr, addr, flags);
-	check(instr_is_branch_to_addr(&instr, addr));
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr));
 
 	/* Branch to self - 0x100 */
 	err = create_cond_branch(&instr, iptr, addr - 0x100, flags);
-	check(instr_is_branch_to_addr(&instr, addr - 0x100));
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr - 0x100));
 
 	/* Branch to self + 0x100 */
 	err = create_cond_branch(&instr, iptr, addr + 0x100, flags);
-	check(instr_is_branch_to_addr(&instr, addr + 0x100));
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr + 0x100));
 
 	/* Maximum relative negative offset, - 32 KB */
 	err = create_cond_branch(&instr, iptr, addr - 0x8000, flags);
-	check(instr_is_branch_to_addr(&instr, addr - 0x8000));
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr - 0x8000));
 
 	/* Out of range relative negative offset, - 32 KB + 4*/
 	err = create_cond_branch(&instr, iptr, addr - 0x8004, flags);
@@ -576,7 +586,8 @@ static void __init test_branch_bform(void)
 
 	/* Check flags are masked correctly */
 	err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC);
-	check(instr_is_branch_to_addr(&instr, addr));
+	patch_instruction(iptr, instr);
+	check(instr_is_branch_to_addr(iptr, addr));
 	check(ppc_inst_equal(instr, ppc_inst(0x43FF0000)));
 }
 
-- 
2.25.0


  parent reply	other threads:[~2021-05-20 13:51 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-20 13:50 [PATCH v2 00/12] powerpc: Cleanup use of 'struct ppc_inst' Christophe Leroy
2021-05-20 13:50 ` [PATCH v2 01/12] powerpc/inst: Fix sparse detection on get_user_instr() Christophe Leroy
2021-05-20 13:50 ` [PATCH v2 02/12] powerpc/inst: Reduce casts in get_user_instr() Christophe Leroy
2021-05-20 13:50 ` [PATCH v2 03/12] powerpc/inst: Improve readability of get_user_instr() and friends Christophe Leroy
2021-05-20 13:50 ` [PATCH v2 04/12] powerpc/inst: Avoid pointer dereferencing in ppc_inst_equal() Christophe Leroy
2021-06-15  3:38   ` Jordan Niethe
2021-05-20 13:50 ` [PATCH v2 05/12] powerpc: Do not dereference code as 'struct ppc_inst' (uprobe, code-patching, feature-fixups) Christophe Leroy
2021-06-15  3:41   ` Jordan Niethe
2021-05-20 13:50 ` [PATCH v2 06/12] powerpc/lib/code-patching: Make instr_is_branch_to_addr() static Christophe Leroy
2021-06-15  3:42   ` Jordan Niethe
2021-05-20 13:50 ` Christophe Leroy [this message]
2021-06-15  3:42   ` [PATCH v2 07/12] powerpc/lib/code-patching: Don't use struct 'ppc_inst' for runnable code in tests Jordan Niethe
2021-05-20 13:50 ` [PATCH v2 08/12] powerpc: Don't use 'struct ppc_inst' to reference instruction location Christophe Leroy
2021-06-15  2:01   ` Michael Ellerman
2021-06-15  3:47     ` Jordan Niethe
2021-05-20 13:50 ` [PATCH v2 09/12] powerpc/inst: Refactor PPC32 and PPC64 versions Christophe Leroy
2021-06-15  3:48   ` Jordan Niethe
2021-05-20 13:50 ` [PATCH v2 10/12] powerpc/optprobes: Minimise casts Christophe Leroy
2021-05-20 13:50 ` [PATCH v2 11/12] powerpc/optprobes: Compact code source a bit Christophe Leroy
2021-05-20 13:50 ` [PATCH v2 12/12] powerpc/optprobes: use PPC_RAW_ macros Christophe Leroy
2021-06-08 12:46 ` [PATCH v2 00/12] powerpc: Cleanup use of 'struct ppc_inst' Christophe Leroy
2021-06-15  7:18 ` Michael Ellerman
2021-06-15  7:24   ` Christophe Leroy
2021-06-16 13:05     ` Michael Ellerman
2021-06-18  3:51 ` Michael Ellerman

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