[PATCH 4.4 33/93] MIPS: uprobes: remove incorrect set_orig_insn

[PATCH 4.4 33/93] MIPS: uprobes: remove incorrect set_orig_insn

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marcin Nowakowski <marcin.nowakowski@imgtec.com>

commit ddabfa5c2e33f1b495f3e0176de7057850915c0b upstream.

Generic kernel code implements a weak version of set_orig_insn that
moves cached 'insn' from arch_uprobe to the original code location when
the trap is removed.
MIPS variant used arch_uprobe->orig_inst which was never initialised
properly, so this code only inserted a nop instead of the original
instruction. With that change orig_inst can also be safely removed.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a506eb ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14299/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/asm/uprobes.h |    1 -
 arch/mips/kernel/uprobes.c      |   18 ------------------
 2 files changed, 19 deletions(-)

--- a/arch/mips/include/asm/uprobes.h
+++ b/arch/mips/include/asm/uprobes.h
@@ -36,7 +36,6 @@ struct arch_uprobe {
 	unsigned long	resume_epc;
 	u32	insn[2];
 	u32	ixol[2];
-	union	mips_instruction orig_inst[MAX_UINSN_BYTES / 4];
 };
 
 struct arch_uprobe_task {
--- a/arch/mips/kernel/uprobes.c
+++ b/arch/mips/kernel/uprobes.c
@@ -280,24 +280,6 @@ int __weak set_swbp(struct arch_uprobe *
 	return uprobe_write_opcode(mm, vaddr, UPROBE_SWBP_INSN);
 }
 
-/**
- * set_orig_insn - Restore the original instruction.
- * @mm: the probed process address space.
- * @auprobe: arch specific probepoint information.
- * @vaddr: the virtual address to insert the opcode.
- *
- * For mm @mm, restore the original opcode (opcode) at @vaddr.
- * Return 0 (success) or a negative errno.
- *
- * This overrides the weak version in kernel/events/uprobes.c.
- */
-int set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
-		 unsigned long vaddr)
-{
-	return uprobe_write_opcode(mm, vaddr,
-			*(uprobe_opcode_t *)&auprobe->orig_inst[0].word);
-}
-
 void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
 				  void *src, unsigned long len)
 {

[PATCH 4.4 34/93] MIPS: fix uretprobe implementation

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marcin Nowakowski <marcin.nowakowski@imgtec.com>

commit db06068a4fd44a57b642b369d2a295b8448f6b65 upstream.

arch_uretprobe_hijack_return_addr should replace the return address for
a call with a trampoline address.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a506eb ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14298/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/uprobes.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kernel/uprobes.c
+++ b/arch/mips/kernel/uprobes.c
@@ -257,7 +257,7 @@ unsigned long arch_uretprobe_hijack_retu
 	ra = regs->regs[31];
 
 	/* Replace the return address with the trampoline address */
-	regs->regs[31] = ra;
+	regs->regs[31] = trampoline_vaddr;
 
 	return ra;
 }

[PATCH 4.4 35/93] MIPS: Malta: Fix IOCU disable switch read for MIPS64

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Paul Burton <paul.burton@imgtec.com>

commit 305723ab439e14debc1d339aa04e835d488b8253 upstream.

Malta boards used with CPU emulators feature a switch to disable use of
an IOCU. Software has to check this switch & ignore any present IOCU if
the switch is closed. The read used to do this was unsafe for 64 bit
kernels, as it simply casted the address 0xbf403000 to a pointer &
dereferenced it. Whilst in a 32 bit kernel this would access kseg1, in a
64 bit kernel this attempts to access xuseg & results in an address
error exception.

Fix by accessing a correctly formed ckseg1 address generated using the
CKSEG1ADDR macro.

Whilst modifying this code, define the name of the register and the bit
we care about within it, which indicates whether PCI DMA is routed to
the IOCU or straight to DRAM. The code previously checked that bit 0 was
also set, but the least significant 7 bits of the CONFIG_GEN0 register
contain the value of the MReqInfo signal provided to the IOCU OCP bus,
so singling out bit 0 makes little sense & that part of the check is
dropped.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: b6d92b4a6bdb ("MIPS: Add option to disable software I/O coherency.")
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14187/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/mti-malta/malta-setup.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/arch/mips/mti-malta/malta-setup.c
+++ b/arch/mips/mti-malta/malta-setup.c
@@ -39,6 +39,9 @@
 #include <linux/console.h>
 #endif
 
+#define ROCIT_CONFIG_GEN0		0x1f403000
+#define  ROCIT_CONFIG_GEN0_PCI_IOCU	BIT(7)
+
 extern void malta_be_init(void);
 extern int malta_be_handler(struct pt_regs *regs, int is_fixup);
 
@@ -107,6 +110,8 @@ static void __init fd_activate(void)
 static int __init plat_enable_iocoherency(void)
 {
 	int supported = 0;
+	u32 cfg;
+
 	if (mips_revision_sconid == MIPS_REVISION_SCON_BONITO) {
 		if (BONITO_PCICACHECTRL & BONITO_PCICACHECTRL_CPUCOH_PRES) {
 			BONITO_PCICACHECTRL |= BONITO_PCICACHECTRL_CPUCOH_EN;
@@ -129,7 +134,8 @@ static int __init plat_enable_iocoherenc
 	} else if (mips_cm_numiocu() != 0) {
 		/* Nothing special needs to be done to enable coherency */
 		pr_info("CMP IOCU detected\n");
-		if ((*(unsigned int *)0xbf403000 & 0x81) != 0x81) {
+		cfg = __raw_readl((u32 *)CKSEG1ADDR(ROCIT_CONFIG_GEN0));
+		if (!(cfg & ROCIT_CONFIG_GEN0_PCI_IOCU)) {
 			pr_crit("IOCU OPERATION DISABLED BY SWITCH - DEFAULTING TO SW IO COHERENCY\n");
 			return 0;
 		}

[PATCH 4.4 36/93] MIPS: uprobes: fix use of uninitialised variable

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marcin Nowakowski <marcin.nowakowski@imgtec.com>

commit ca86c9ef2b322ebf24772009fdea037688cbdac1 upstream.

arch_uprobe_pre_xol needs to emulate a branch if a branch instruction
has been replaced with a breakpoint, but in fact an uninitialised local
variable was passed to the emulator routine instead of the original
instruction

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a506eb ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14300/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/uprobes.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/arch/mips/kernel/uprobes.c
+++ b/arch/mips/kernel/uprobes.c
@@ -157,7 +157,6 @@ bool is_trap_insn(uprobe_opcode_t *insn)
 int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs)
 {
 	struct uprobe_task *utask = current->utask;
-	union mips_instruction insn;
 
 	/*
 	 * Now find the EPC where to resume after the breakpoint has been
@@ -168,10 +167,10 @@ int arch_uprobe_pre_xol(struct arch_upro
 		unsigned long epc;
 
 		epc = regs->cp0_epc;
-		__compute_return_epc_for_insn(regs, insn);
+		__compute_return_epc_for_insn(regs,
+			(union mips_instruction) aup->insn[0]);
 		aup->resume_epc = regs->cp0_epc;
 	}
-
 	utask->autask.saved_trap_nr = current->thread.trap_nr;
 	current->thread.trap_nr = UPROBE_TRAP_NR;
 	regs->cp0_epc = current->utask->xol_vaddr;