This is a note to let you know that I've just added the patch titled
powerpc/lib/code-patching: Don't use struct 'ppc_inst' for runnable code in tests.
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-lib-code-patching-don-t-use-struct-ppc_inst-.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit dc4771f7058cd7e5d9fa85c421534d86e6116ee4
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date: Thu May 20 13:50:44 2021 +0000
powerpc/lib/code-patching: Don't use struct 'ppc_inst' for runnable code in tests.
[ Upstream commit e90a21ea801d1776d9a786ad02354fd3fe23ce09 ]
'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@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/d8425fb42a4adebc35b7509f121817eeb02fac31.1621516826.git.christophe.leroy@xxxxxxxxxx
Stable-dep-of: 97f88a3d7231 ("powerpc/kprobes: Fix null pointer reference in arch_prepare_kprobe()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index a2e4f864b63d..ba3ccadc1a8c 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;
+ u32 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;
+ u32 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)));
}
