From 3e65412709293d5fb65249408e8e801b23b72635 Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Thu, 6 Oct 2022 14:20:18 +1100
Subject: powerpc: Make instruction dump work with scripts/decodecode

Matt reported that scripts/decodecode doesn't work for the instruction
dump in the powerpc oops output. Although there are scripts around that
can decode it, it would be preferable if the standard in-tree script
worked.

All other arches prefix the instruction dump with "Code:", and that's
what the script looks for, so use that.

The script then works as expected:

  $ CROSS_COMPILE=powerpc64le-linux-gnu- ./scripts/decodecode
  Code:
  fbc1fff0 f821ffc1 7c7d1b78 7c9c2378 ebc30028 7fdff378 48000018 60000000
  60000000 ebff0008 7c3ef840 41820048 <815f0060> e93f0000 5529077c 7d295378
  ^D

  All code
  ========
     0:   f0 ff c1 fb     std     r30,-16(r1)
     4:   c1 ff 21 f8     stdu    r1,-64(r1)
     8:   78 1b 7d 7c     mr      r29,r3
     ...

Note that the script doesn't cope well with printk timestamps or printk
caller info.

Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221006032019.1128624-1-mpe@ellerman.id.au
---
 arch/powerpc/kernel/process.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 67da147fe34d..3372b5c21168 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1359,7 +1359,7 @@ static void show_instructions(struct pt_regs *regs)
 	unsigned long nip = regs->nip;
 	unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
 
-	printk("Instruction dump:");
+	printk("Code:");
 
 	/*
 	 * If we were executing with the MMU off for instructions, adjust pc
-- 
cgit v1.2.3


From d90bb7b4fdaff3f2fa68c7af85de2ce9e70189b1 Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Thu, 6 Oct 2022 14:20:19 +1100
Subject: powerpc: Print instruction dump on a single line

Although the previous commit made the powerpc instruction dump usable
with scripts/decodecode, there are still some problems.

Because the dump is split across multiple lines, the script doesn't cope
with printk timestamps or caller info.

That can be fixed by printing the entire dump on one line, eg:

  [   12.016307][  T112] --- interrupt: c00
  [   12.016605][  T112] Code: 4b7aae15 60000000 3d22016e 3c62ffec 39291160 38639bc0 e8890000 4b7aadf9 60000000 4bfffee8 7c0802a6 60000000 <0fe00000> 60420000 3c4c008f 384268a0
  [   12.017655][  T112] ---[ end trace 0000000000000000 ]---

That output can then be piped directly into scripts/decodecode and
interpreted correctly.

Printing the dump on a single line does produce a very long line, about
173 characters. That is still shorter than x86, which prints nearly 200
characters even without timestamps etc.

All consoles I'm aware of will wrap the line if it's too long, so the
length should not be a functional problem. If anything it should help on
consoles like VGA by using less vertical space.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221006032019.1128624-2-mpe@ellerman.id.au
---
 arch/powerpc/kernel/process.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3372b5c21168..e3e1feaa536a 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1359,7 +1359,7 @@ static void show_instructions(struct pt_regs *regs)
 	unsigned long nip = regs->nip;
 	unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
 
-	printk("Code:");
+	printk("Code: ");
 
 	/*
 	 * If we were executing with the MMU off for instructions, adjust pc
@@ -1373,9 +1373,6 @@ static void show_instructions(struct pt_regs *regs)
 	for (i = 0; i < NR_INSN_TO_PRINT; i++) {
 		int instr;
 
-		if (!(i % 8))
-			pr_cont("\n");
-
 		if (!__kernel_text_address(pc) ||
 		    get_kernel_nofault(instr, (const void *)pc)) {
 			pr_cont("XXXXXXXX ");
-- 
cgit v1.2.3


From 3671f4ebe3eb12e7222e4d7b0f94e85cfe34253a Mon Sep 17 00:00:00 2001
From: Jordan Niethe <jniethe5@gmail.com>
Date: Wed, 9 Nov 2022 15:51:04 +1100
Subject: powerpc: Allow clearing and restoring registers independent of saved
 breakpoint state

For the coming temporary mm used for instruction patching, the
breakpoint registers need to be cleared to prevent them from
accidentally being triggered. As soon as the patching is done, the
breakpoints will be restored.

The breakpoint state is stored in the per-cpu variable current_brk[].
Add a suspend_breakpoints() function which will clear the breakpoint
registers without touching the state in current_brk[]. Add a pair
function restore_breakpoints() which will move the state in
current_brk[] back to the registers.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221109045112.187069-2-bgray@linux.ibm.com
---
 arch/powerpc/include/asm/debug.h |  2 ++
 arch/powerpc/kernel/process.c    | 38 +++++++++++++++++++++++++++++++++++---
 2 files changed, 37 insertions(+), 3 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index 86a14736c76c..51c744608f37 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -46,6 +46,8 @@ static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
 #endif
 
 void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk);
+void suspend_breakpoints(void);
+void restore_breakpoints(void);
 bool ppc_breakpoint_available(void);
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 extern void do_send_trap(struct pt_regs *regs, unsigned long address,
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index e3e1feaa536a..5265da2d8034 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -862,10 +862,8 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
 	return 0;
 }
 
-void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
+static void set_hw_breakpoint(int nr, struct arch_hw_breakpoint *brk)
 {
-	memcpy(this_cpu_ptr(&current_brk[nr]), brk, sizeof(*brk));
-
 	if (dawr_enabled())
 		// Power8 or later
 		set_dawr(nr, brk);
@@ -879,6 +877,12 @@ void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
 		WARN_ON_ONCE(1);
 }
 
+void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
+{
+	memcpy(this_cpu_ptr(&current_brk[nr]), brk, sizeof(*brk));
+	set_hw_breakpoint(nr, brk);
+}
+
 /* Check if we have DAWR or DABR hardware */
 bool ppc_breakpoint_available(void)
 {
@@ -891,6 +895,34 @@ bool ppc_breakpoint_available(void)
 }
 EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
 
+/* Disable the breakpoint in hardware without touching current_brk[] */
+void suspend_breakpoints(void)
+{
+	struct arch_hw_breakpoint brk = {0};
+	int i;
+
+	if (!ppc_breakpoint_available())
+		return;
+
+	for (i = 0; i < nr_wp_slots(); i++)
+		set_hw_breakpoint(i, &brk);
+}
+
+/*
+ * Re-enable breakpoints suspended by suspend_breakpoints() in hardware
+ * from current_brk[]
+ */
+void restore_breakpoints(void)
+{
+	int i;
+
+	if (!ppc_breakpoint_available())
+		return;
+
+	for (i = 0; i < nr_wp_slots(); i++)
+		set_hw_breakpoint(i, this_cpu_ptr(&current_brk[i]));
+}
+
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 
 static inline bool tm_enabled(struct task_struct *tsk)
-- 
cgit v1.2.3


From bc0677363d0ffaec0c56685291e97b080116976c Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:29 +1000
Subject: powerpc: Rearrange copy_thread child stack creation

This makes it a bit clearer where the stack frame is created, and will
allow easier use of some of the stack offset constants in a later
change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-5-npiggin@gmail.com
---
 arch/powerpc/kernel/process.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 5265da2d8034..f93703ea4a12 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1755,13 +1755,16 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 
 	klp_init_thread_info(p);
 
+	/* Create initial stack frame. */
+	sp -= (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD);
+	((unsigned long *)sp)[0] = 0;
+
 	/* Copy registers */
-	sp -= sizeof(struct pt_regs);
-	childregs = (struct pt_regs *) sp;
+	childregs = (struct pt_regs *)(sp + STACK_FRAME_OVERHEAD);
 	if (unlikely(args->fn)) {
 		/* kernel thread */
 		memset(childregs, 0, sizeof(struct pt_regs));
-		childregs->gpr[1] = sp + sizeof(struct pt_regs);
+		childregs->gpr[1] = sp + (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD);
 		/* function */
 		if (args->fn)
 			childregs->gpr[14] = ppc_function_entry((void *)args->fn);
@@ -1796,7 +1799,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 			f = ret_from_fork;
 	}
 	childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
-	sp -= STACK_FRAME_OVERHEAD;
 
 	/*
 	 * The way this works is that at some point in the future
@@ -1806,7 +1808,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	 * do some house keeping and then return from the fork or clone
 	 * system call, using the stack frame created above.
 	 */
-	((unsigned long *)sp)[0] = 0;
 	sp -= sizeof(struct pt_regs);
 	kregs = (struct pt_regs *) sp;
 	sp -= STACK_FRAME_OVERHEAD;
-- 
cgit v1.2.3


From c03be0a3f3cc656eab5c427b78959b8f1b169a11 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:32 +1000
Subject: powerpc: add definition for pt_regs offset within an interrupt frame

This is a common offset that currently uses the overloaded
STACK_FRAME_OVERHEAD constant. It's easier to read and more
flexible to use a specific regs offset for this.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-8-npiggin@gmail.com
---
 arch/powerpc/include/asm/ptrace.h               |  2 +
 arch/powerpc/kernel/asm-offsets.c               |  7 +--
 arch/powerpc/kernel/entry_32.S                  |  6 +-
 arch/powerpc/kernel/exceptions-64e.S            | 42 ++++++-------
 arch/powerpc/kernel/exceptions-64s.S            | 80 ++++++++++++-------------
 arch/powerpc/kernel/head_32.h                   |  2 +-
 arch/powerpc/kernel/head_85xx.S                 |  4 +-
 arch/powerpc/kernel/head_booke.h                |  2 +-
 arch/powerpc/kernel/interrupt_64.S              | 22 +++----
 arch/powerpc/kernel/kgdb.c                      |  2 +-
 arch/powerpc/kernel/optprobes_head.S            |  4 +-
 arch/powerpc/kernel/ppc_save_regs.S             |  2 +-
 arch/powerpc/kernel/process.c                   |  4 +-
 arch/powerpc/kernel/tm.S                        |  8 +--
 arch/powerpc/kernel/trace/ftrace_mprofile.S     |  2 +-
 arch/powerpc/lib/test_emulate_step_exec_instr.S |  2 +-
 arch/powerpc/perf/callchain.c                   |  2 +-
 arch/powerpc/xmon/xmon.c                        |  7 +--
 18 files changed, 100 insertions(+), 100 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 2efec6d87049..a4ae67aa9b76 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -124,6 +124,7 @@ struct pt_regs
 #define STACK_FRAME_LR_SAVE	2	/* Location of LR in stack frame */
 #define STACK_INT_FRAME_SIZE	(sizeof(struct pt_regs) + \
 				 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)
+#define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_FRAME_MARKER	12
 
 #ifdef CONFIG_PPC64_ELF_ABI_V2
@@ -143,6 +144,7 @@ struct pt_regs
 #define STACK_FRAME_OVERHEAD	16	/* size of minimum stack frame */
 #define STACK_FRAME_LR_SAVE	1	/* Location of LR in stack frame */
 #define STACK_INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
+#define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_FRAME_MARKER	2
 #define STACK_FRAME_MIN_SIZE	STACK_FRAME_OVERHEAD
 
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index b4b661f631f5..68905c9f7c21 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -72,7 +72,7 @@
 #endif
 
 #define STACK_PT_REGS_OFFSET(sym, val)	\
-	DEFINE(sym, STACK_FRAME_OVERHEAD + offsetof(struct pt_regs, val))
+	DEFINE(sym, STACK_INT_FRAME_REGS + offsetof(struct pt_regs, val))
 
 int main(void)
 {
@@ -167,9 +167,8 @@ int main(void)
 	OFFSET(THREAD_CKVRSTATE, thread_struct, ckvr_state.vr);
 	OFFSET(THREAD_CKVRSAVE, thread_struct, ckvrsave);
 	OFFSET(THREAD_CKFPSTATE, thread_struct, ckfp_state.fpr);
-	/* Local pt_regs on stack for Transactional Memory funcs. */
-	DEFINE(TM_FRAME_SIZE, STACK_FRAME_OVERHEAD +
-	       sizeof(struct pt_regs) + 16);
+	/* Local pt_regs on stack in int frame form, plus 16 bytes for TM */
+	DEFINE(TM_FRAME_SIZE, STACK_INT_FRAME_SIZE + 16);
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
 	OFFSET(TI_LOCAL_FLAGS, thread_info, local_flags);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 3fc7c9886bb7..24c8d84a56c9 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -123,12 +123,12 @@ transfer_to_syscall:
 	kuep_lock
 
 	/* Calling convention has r3 = regs, r4 = orig r0 */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	mr	r4,r0
 	bl	system_call_exception
 
 ret_from_syscall:
-	addi    r4,r1,STACK_FRAME_OVERHEAD
+	addi    r4,r1,STACK_INT_FRAME_REGS
 	li	r5,0
 	bl	syscall_exit_prepare
 #ifdef CONFIG_PPC_47x
@@ -293,7 +293,7 @@ _ASM_NOKPROBE_SYMBOL(fast_exception_return)
 	.globl interrupt_return
 interrupt_return:
 	lwz	r4,_MSR(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	andi.	r0,r4,MSR_PR
 	beq	.Lkernel_interrupt_return
 	bl	interrupt_exit_user_prepare
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 2f68fb2ee4fc..62033d022e0a 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -455,7 +455,7 @@ exc_##n##_bad_stack:							    \
 	EXCEPTION_COMMON(trapnum)					\
 	ack(r8);							\
 	CHECK_NAPPING();						\
-	addi	r3,r1,STACK_FRAME_OVERHEAD;				\
+	addi	r3,r1,STACK_INT_FRAME_REGS;				\
 	bl	hdlr;							\
 	b	interrupt_return
 
@@ -504,7 +504,7 @@ __end_interrupts:
 	EXCEPTION_COMMON_CRIT(0x100)
 	bl	special_reg_save
 	CHECK_NAPPING();
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_nmi_exception
 	b	ret_from_crit_except
 
@@ -515,7 +515,7 @@ __end_interrupts:
 	EXCEPTION_COMMON_MC(0x000)
 	bl	special_reg_save
 	CHECK_NAPPING();
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	machine_check_exception
 	b	ret_from_mc_except
 
@@ -570,7 +570,7 @@ __end_interrupts:
 	std	r14,_ESR(r1)
 	ld	r14,PACA_EXGEN+EX_R14(r13)
 	EXCEPTION_COMMON(0x700)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	program_check_exception
 	REST_NVGPRS(r1)
 	b	interrupt_return
@@ -586,7 +586,7 @@ __end_interrupts:
 	beq-	1f
 	bl	load_up_fpu
 	b	fast_interrupt_return
-1:	addi	r3,r1,STACK_FRAME_OVERHEAD
+1:	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	kernel_fp_unavailable_exception
 	b	interrupt_return
 
@@ -606,7 +606,7 @@ BEGIN_FTR_SECTION
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	altivec_unavailable_exception
 	b	interrupt_return
 
@@ -616,7 +616,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 				BOOKE_INTERRUPT_ALTIVEC_ASSIST,
 				PROLOG_ADDITION_NONE)
 	EXCEPTION_COMMON(0x220)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 #ifdef CONFIG_ALTIVEC
 BEGIN_FTR_SECTION
 	bl	altivec_assist_exception
@@ -643,7 +643,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	EXCEPTION_COMMON_CRIT(0x9f0)
 	bl	special_reg_save
 	CHECK_NAPPING();
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 #ifdef CONFIG_BOOKE_WDT
 	bl	WatchdogException
 #else
@@ -664,7 +664,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	NORMAL_EXCEPTION_PROLOG(0xf20, BOOKE_INTERRUPT_AP_UNAVAIL,
 				PROLOG_ADDITION_NONE)
 	EXCEPTION_COMMON(0xf20)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_exception
 	b	interrupt_return
 
@@ -731,7 +731,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	ld	r14,PACA_EXCRIT+EX_R14(r13)
 	ld	r15,PACA_EXCRIT+EX_R15(r13)
 	EXCEPTION_COMMON_CRIT(0xd00)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	DebugException
 	REST_NVGPRS(r1)
 	b	interrupt_return
@@ -802,7 +802,7 @@ kernel_dbg_exc:
 	ld	r14,PACA_EXDBG+EX_R14(r13)
 	ld	r15,PACA_EXDBG+EX_R15(r13)
 	EXCEPTION_COMMON_DBG(0xd08)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	DebugException
 	REST_NVGPRS(r1)
 	b	interrupt_return
@@ -812,7 +812,7 @@ kernel_dbg_exc:
 				PROLOG_ADDITION_NONE)
 	EXCEPTION_COMMON(0x260)
 	CHECK_NAPPING()
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	/*
 	 * XXX: Returning from performance_monitor_exception taken as a
 	 * soft-NMI (Linux irqs disabled) may be risky to use interrupt_return
@@ -834,7 +834,7 @@ kernel_dbg_exc:
 	EXCEPTION_COMMON_CRIT(0x2a0)
 	bl	special_reg_save
 	CHECK_NAPPING();
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_nmi_exception
 	b	ret_from_crit_except
 
@@ -846,7 +846,7 @@ kernel_dbg_exc:
 	GDBELL_EXCEPTION_PROLOG(0x2c0, BOOKE_INTERRUPT_GUEST_DBELL,
 			        PROLOG_ADDITION_NONE)
 	EXCEPTION_COMMON(0x2c0)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_exception
 	b	interrupt_return
 
@@ -857,7 +857,7 @@ kernel_dbg_exc:
 	EXCEPTION_COMMON_CRIT(0x2e0)
 	bl	special_reg_save
 	CHECK_NAPPING();
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_nmi_exception
 	b	ret_from_crit_except
 
@@ -866,7 +866,7 @@ kernel_dbg_exc:
 	NORMAL_EXCEPTION_PROLOG(0x310, BOOKE_INTERRUPT_HV_SYSCALL,
 			        PROLOG_ADDITION_NONE)
 	EXCEPTION_COMMON(0x310)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_exception
 	b	interrupt_return
 
@@ -875,7 +875,7 @@ kernel_dbg_exc:
 	NORMAL_EXCEPTION_PROLOG(0x320, BOOKE_INTERRUPT_HV_PRIV,
 			        PROLOG_ADDITION_NONE)
 	EXCEPTION_COMMON(0x320)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_exception
 	b	interrupt_return
 
@@ -884,7 +884,7 @@ kernel_dbg_exc:
 	NORMAL_EXCEPTION_PROLOG(0x340, BOOKE_INTERRUPT_LRAT_ERROR,
 			        PROLOG_ADDITION_NONE)
 	EXCEPTION_COMMON(0x340)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_exception
 	b	interrupt_return
 
@@ -979,7 +979,7 @@ masked_interrupt_book3e_0x2c0:
  * original values stashed away in the PACA
  */
 storage_fault_common:
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	do_page_fault
 	b	interrupt_return
 
@@ -988,7 +988,7 @@ storage_fault_common:
  * continues here.
  */
 alignment_more:
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	alignment_exception
 	REST_NVGPRS(r1)
 	b	interrupt_return
@@ -1069,7 +1069,7 @@ bad_stack_book3e:
 	ZEROIZE_GPR(12)
 	std	r12,0(r11)
 	LOAD_PACA_TOC()
-1:	addi	r3,r1,STACK_FRAME_OVERHEAD
+1:	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	kernel_bad_stack
 	b	1b
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 651c36b056bd..29b78536ca59 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1061,7 +1061,7 @@ EXC_COMMON_BEGIN(system_reset_common)
 	subi	r1,r1,INT_FRAME_SIZE
 	__GEN_COMMON_BODY system_reset
 
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	system_reset_exception
 
 	/* Clear MSR_RI before setting SRR0 and SRR1. */
@@ -1208,7 +1208,7 @@ EXC_COMMON_BEGIN(machine_check_early_common)
 BEGIN_FTR_SECTION
 	bl	enable_machine_check
 END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 BEGIN_FTR_SECTION
 	bl	machine_check_early_boot
 END_FTR_SECTION(0, 1)     // nop out after boot
@@ -1298,7 +1298,7 @@ EXC_COMMON_BEGIN(machine_check_common)
 	 * save area: PACA_EXMC instead of PACA_EXGEN.
 	 */
 	GEN_COMMON machine_check
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	machine_check_exception_async
 	b	interrupt_return_srr
 
@@ -1364,14 +1364,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
 	 * This is the NMI version of the handler because we are called from
 	 * the early handler which is a true NMI.
 	 */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	machine_check_exception
 
 	/*
 	 * We will not reach here. Even if we did, there is no way out.
 	 * Call unrecoverable_exception and die.
 	 */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unrecoverable_exception
 	b	.
 
@@ -1422,7 +1422,7 @@ EXC_VIRT_END(data_access, 0x4300, 0x80)
 EXC_COMMON_BEGIN(data_access_common)
 	GEN_COMMON data_access
 	ld	r4,_DSISR(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	andis.	r0,r4,DSISR_DABRMATCH@h
 	bne-	1f
 #ifdef CONFIG_PPC_64S_HASH_MMU
@@ -1479,7 +1479,7 @@ EXC_COMMON_BEGIN(data_access_slb_common)
 #ifdef CONFIG_PPC_64S_HASH_MMU
 BEGIN_MMU_FTR_SECTION
 	/* HPT case, do SLB fault */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	do_slb_fault
 	cmpdi	r3,0
 	bne-	1f
@@ -1493,7 +1493,7 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	li	r3,-EFAULT
 #endif
 	std	r3,RESULT(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	do_bad_segment_interrupt
 	b	interrupt_return_srr
 
@@ -1525,7 +1525,7 @@ EXC_VIRT_BEGIN(instruction_access, 0x4400, 0x80)
 EXC_VIRT_END(instruction_access, 0x4400, 0x80)
 EXC_COMMON_BEGIN(instruction_access_common)
 	GEN_COMMON instruction_access
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 #ifdef CONFIG_PPC_64S_HASH_MMU
 BEGIN_MMU_FTR_SECTION
 	bl	do_hash_fault
@@ -1567,7 +1567,7 @@ EXC_COMMON_BEGIN(instruction_access_slb_common)
 #ifdef CONFIG_PPC_64S_HASH_MMU
 BEGIN_MMU_FTR_SECTION
 	/* HPT case, do SLB fault */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	do_slb_fault
 	cmpdi	r3,0
 	bne-	1f
@@ -1581,7 +1581,7 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	li	r3,-EFAULT
 #endif
 	std	r3,RESULT(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	do_bad_segment_interrupt
 	b	interrupt_return_srr
 
@@ -1635,7 +1635,7 @@ EXC_VIRT_BEGIN(hardware_interrupt, 0x4500, 0x100)
 EXC_VIRT_END(hardware_interrupt, 0x4500, 0x100)
 EXC_COMMON_BEGIN(hardware_interrupt_common)
 	GEN_COMMON hardware_interrupt
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	do_IRQ
 	BEGIN_FTR_SECTION
 	b	interrupt_return_hsrr
@@ -1665,7 +1665,7 @@ EXC_VIRT_BEGIN(alignment, 0x4600, 0x100)
 EXC_VIRT_END(alignment, 0x4600, 0x100)
 EXC_COMMON_BEGIN(alignment_common)
 	GEN_COMMON alignment
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	alignment_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return_srr
@@ -1731,7 +1731,7 @@ EXC_COMMON_BEGIN(program_check_common)
 	__GEN_COMMON_BODY program_check
 
 .Ldo_program_check:
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	program_check_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return_srr
@@ -1762,7 +1762,7 @@ EXC_VIRT_END(fp_unavailable, 0x4800, 0x100)
 EXC_COMMON_BEGIN(fp_unavailable_common)
 	GEN_COMMON fp_unavailable
 	bne	1f			/* if from user, just load it up */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	kernel_fp_unavailable_exception
 0:	trap
 	EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
@@ -1780,7 +1780,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
 	b	fast_interrupt_return_srr
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:	/* User process was in a transaction */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	fp_unavailable_tm
 	b	interrupt_return_srr
 #endif
@@ -1824,7 +1824,7 @@ EXC_VIRT_BEGIN(decrementer, 0x4900, 0x80)
 EXC_VIRT_END(decrementer, 0x4900, 0x80)
 EXC_COMMON_BEGIN(decrementer_common)
 	GEN_COMMON decrementer
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	timer_interrupt
 	b	interrupt_return_srr
 
@@ -1909,7 +1909,7 @@ EXC_VIRT_BEGIN(doorbell_super, 0x4a00, 0x100)
 EXC_VIRT_END(doorbell_super, 0x4a00, 0x100)
 EXC_COMMON_BEGIN(doorbell_super_common)
 	GEN_COMMON doorbell_super
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 #ifdef CONFIG_PPC_DOORBELL
 	bl	doorbell_exception
 #else
@@ -2076,7 +2076,7 @@ EXC_VIRT_BEGIN(single_step, 0x4d00, 0x100)
 EXC_VIRT_END(single_step, 0x4d00, 0x100)
 EXC_COMMON_BEGIN(single_step_common)
 	GEN_COMMON single_step
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	single_step_exception
 	b	interrupt_return_srr
 
@@ -2110,7 +2110,7 @@ EXC_VIRT_BEGIN(h_data_storage, 0x4e00, 0x20)
 EXC_VIRT_END(h_data_storage, 0x4e00, 0x20)
 EXC_COMMON_BEGIN(h_data_storage_common)
 	GEN_COMMON h_data_storage
-	addi    r3,r1,STACK_FRAME_OVERHEAD
+	addi    r3,r1,STACK_INT_FRAME_REGS
 BEGIN_MMU_FTR_SECTION
 	bl      do_bad_page_fault_segv
 MMU_FTR_SECTION_ELSE
@@ -2139,7 +2139,7 @@ EXC_VIRT_BEGIN(h_instr_storage, 0x4e20, 0x20)
 EXC_VIRT_END(h_instr_storage, 0x4e20, 0x20)
 EXC_COMMON_BEGIN(h_instr_storage_common)
 	GEN_COMMON h_instr_storage
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_exception
 	b	interrupt_return_hsrr
 
@@ -2162,7 +2162,7 @@ EXC_VIRT_BEGIN(emulation_assist, 0x4e40, 0x20)
 EXC_VIRT_END(emulation_assist, 0x4e40, 0x20)
 EXC_COMMON_BEGIN(emulation_assist_common)
 	GEN_COMMON emulation_assist
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	emulation_assist_interrupt
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return_hsrr
@@ -2222,7 +2222,7 @@ EXC_COMMON_BEGIN(hmi_exception_early_common)
 
 	__GEN_COMMON_BODY hmi_exception_early
 
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	hmi_exception_realmode
 	cmpdi	cr0,r3,0
 	bne	1f
@@ -2240,7 +2240,7 @@ EXC_COMMON_BEGIN(hmi_exception_early_common)
 
 EXC_COMMON_BEGIN(hmi_exception_common)
 	GEN_COMMON hmi_exception
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	handle_hmi_exception
 	b	interrupt_return_hsrr
 
@@ -2274,7 +2274,7 @@ EXC_VIRT_BEGIN(h_doorbell, 0x4e80, 0x20)
 EXC_VIRT_END(h_doorbell, 0x4e80, 0x20)
 EXC_COMMON_BEGIN(h_doorbell_common)
 	GEN_COMMON h_doorbell
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 #ifdef CONFIG_PPC_DOORBELL
 	bl	doorbell_exception
 #else
@@ -2310,7 +2310,7 @@ EXC_VIRT_BEGIN(h_virt_irq, 0x4ea0, 0x20)
 EXC_VIRT_END(h_virt_irq, 0x4ea0, 0x20)
 EXC_COMMON_BEGIN(h_virt_irq_common)
 	GEN_COMMON h_virt_irq
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	do_IRQ
 	b	interrupt_return_hsrr
 
@@ -2356,7 +2356,7 @@ EXC_VIRT_BEGIN(performance_monitor, 0x4f00, 0x20)
 EXC_VIRT_END(performance_monitor, 0x4f00, 0x20)
 EXC_COMMON_BEGIN(performance_monitor_common)
 	GEN_COMMON performance_monitor
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	lbz	r4,PACAIRQSOFTMASK(r13)
 	cmpdi	r4,IRQS_ENABLED
 	bne	1f
@@ -2410,14 +2410,14 @@ BEGIN_FTR_SECTION
 	b	fast_interrupt_return_srr
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:	/* User process was in a transaction */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	altivec_unavailable_tm
 	b	interrupt_return_srr
 #endif
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	altivec_unavailable_exception
 	b	interrupt_return_srr
 
@@ -2458,14 +2458,14 @@ BEGIN_FTR_SECTION
 	b	load_up_vsx
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:	/* User process was in a transaction */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	vsx_unavailable_tm
 	b	interrupt_return_srr
 #endif
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 #endif
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	vsx_unavailable_exception
 	b	interrupt_return_srr
 
@@ -2492,7 +2492,7 @@ EXC_VIRT_BEGIN(facility_unavailable, 0x4f60, 0x20)
 EXC_VIRT_END(facility_unavailable, 0x4f60, 0x20)
 EXC_COMMON_BEGIN(facility_unavailable_common)
 	GEN_COMMON facility_unavailable
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	facility_unavailable_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
 	b	interrupt_return_srr
@@ -2520,7 +2520,7 @@ EXC_VIRT_BEGIN(h_facility_unavailable, 0x4f80, 0x20)
 EXC_VIRT_END(h_facility_unavailable, 0x4f80, 0x20)
 EXC_COMMON_BEGIN(h_facility_unavailable_common)
 	GEN_COMMON h_facility_unavailable
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	facility_unavailable_exception
 	REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
 	b	interrupt_return_hsrr
@@ -2550,7 +2550,7 @@ EXC_REAL_END(cbe_system_error, 0x1200, 0x100)
 EXC_VIRT_NONE(0x5200, 0x100)
 EXC_COMMON_BEGIN(cbe_system_error_common)
 	GEN_COMMON cbe_system_error
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	cbe_system_error_exception
 	b	interrupt_return_hsrr
 
@@ -2581,7 +2581,7 @@ EXC_VIRT_BEGIN(instruction_breakpoint, 0x5300, 0x100)
 EXC_VIRT_END(instruction_breakpoint, 0x5300, 0x100)
 EXC_COMMON_BEGIN(instruction_breakpoint_common)
 	GEN_COMMON instruction_breakpoint
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	instruction_breakpoint_exception
 	b	interrupt_return_srr
 
@@ -2703,7 +2703,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 
 EXC_COMMON_BEGIN(denorm_exception_common)
 	GEN_COMMON denorm_exception
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unknown_exception
 	b	interrupt_return_hsrr
 
@@ -2720,7 +2720,7 @@ EXC_REAL_END(cbe_maintenance, 0x1600, 0x100)
 EXC_VIRT_NONE(0x5600, 0x100)
 EXC_COMMON_BEGIN(cbe_maintenance_common)
 	GEN_COMMON cbe_maintenance
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	cbe_maintenance_exception
 	b	interrupt_return_hsrr
 
@@ -2745,7 +2745,7 @@ EXC_VIRT_BEGIN(altivec_assist, 0x5700, 0x100)
 EXC_VIRT_END(altivec_assist, 0x5700, 0x100)
 EXC_COMMON_BEGIN(altivec_assist_common)
 	GEN_COMMON altivec_assist
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 #ifdef CONFIG_ALTIVEC
 	bl	altivec_assist_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
@@ -2767,7 +2767,7 @@ EXC_REAL_END(cbe_thermal, 0x1800, 0x100)
 EXC_VIRT_NONE(0x5800, 0x100)
 EXC_COMMON_BEGIN(cbe_thermal_common)
 	GEN_COMMON cbe_thermal
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	cbe_thermal_exception
 	b	interrupt_return_hsrr
 
@@ -2800,7 +2800,7 @@ EXC_COMMON_BEGIN(soft_nmi_common)
 	subi	r1,r1,INT_FRAME_SIZE
 	__GEN_COMMON_BODY soft_nmi
 
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	soft_nmi_interrupt
 
 	/* Clear MSR_RI before setting SRR0 and SRR1. */
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index c3286260a7d1..117d25330e13 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -127,7 +127,7 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 	mfspr	r10,SPRN_XER
 	addi	r2, r2, -THREAD
 	stw	r10,_XER(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 .endm
 
 .macro prepare_transfer_to_handler
diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S
index 52c0ab416326..24f39abf81df 100644
--- a/arch/powerpc/kernel/head_85xx.S
+++ b/arch/powerpc/kernel/head_85xx.S
@@ -972,10 +972,10 @@ _GLOBAL(__giveup_spe)
 	li	r4,THREAD_ACC
 	evstddx	evr6, r4, r3		/* save off accumulator */
 	beq	1f
-	lwz	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+	lwz	r4,_MSR-STACK_INT_FRAME_REGS(r5)
 	lis	r3,MSR_SPE@h
 	andc	r4,r4,r3		/* disable SPE for previous task */
-	stw	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+	stw	r4,_MSR-STACK_INT_FRAME_REGS(r5)
 1:
 	blr
 #endif /* CONFIG_SPE */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 1cb9d0f7cbf2..3149ac20b18e 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -99,7 +99,7 @@ END_BTB_FLUSH_SECTION
 	mfspr	r10,SPRN_XER
 	addi	r2, r2, -THREAD
 	stw	r10,_XER(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 .endm
 
 .macro prepare_transfer_to_handler
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index a019ed6fc839..49d585eae7c8 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -78,7 +78,7 @@ _ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
 	std	r12,_CCR(r1)
 	std	r3,ORIG_GPR3(r1)
 	/* Calling convention has r3 = regs, r4 = orig r0 */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	mr	r4,r0
 	LOAD_REG_IMMEDIATE(r11, STACK_FRAME_REGS_MARKER)
 	std	r11,-16(r3)		/* "regshere" marker */
@@ -99,7 +99,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	bl	system_call_exception
 
 .Lsyscall_vectored_\name\()_exit:
-	addi	r4,r1,STACK_FRAME_OVERHEAD
+	addi	r4,r1,STACK_INT_FRAME_REGS
 	li	r5,1 /* scv */
 	bl	syscall_exit_prepare
 	std	r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
@@ -176,7 +176,7 @@ _ASM_NOKPROBE_SYMBOL(syscall_vectored_\name\()_restart)
 	ld	r1,PACA_EXIT_SAVE_R1(r13)
 	LOAD_PACA_TOC()
 	ld	r3,RESULT(r1)
-	addi	r4,r1,STACK_FRAME_OVERHEAD
+	addi	r4,r1,STACK_INT_FRAME_REGS
 	li	r11,IRQS_ALL_DISABLED
 	stb	r11,PACAIRQSOFTMASK(r13)
 	bl	syscall_exit_restart
@@ -251,7 +251,7 @@ END_BTB_FLUSH_SECTION
 	std	r12,_CCR(r1)
 	std	r3,ORIG_GPR3(r1)
 	/* Calling convention has r3 = regs, r4 = orig r0 */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	mr	r4,r0
 	LOAD_REG_IMMEDIATE(r11, STACK_FRAME_REGS_MARKER)
 	std	r11,-16(r3)		/* "regshere" marker */
@@ -278,7 +278,7 @@ END_BTB_FLUSH_SECTION
 	bl	system_call_exception
 
 .Lsyscall_exit:
-	addi	r4,r1,STACK_FRAME_OVERHEAD
+	addi	r4,r1,STACK_INT_FRAME_REGS
 	li	r5,0 /* !scv */
 	bl	syscall_exit_prepare
 	std	r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
@@ -357,7 +357,7 @@ _ASM_NOKPROBE_SYMBOL(syscall_restart)
 	ld	r1,PACA_EXIT_SAVE_R1(r13)
 	LOAD_PACA_TOC()
 	ld	r3,RESULT(r1)
-	addi	r4,r1,STACK_FRAME_OVERHEAD
+	addi	r4,r1,STACK_INT_FRAME_REGS
 	li	r11,IRQS_ALL_DISABLED
 	stb	r11,PACAIRQSOFTMASK(r13)
 	bl	syscall_exit_restart
@@ -388,7 +388,7 @@ _ASM_NOKPROBE_SYMBOL(fast_interrupt_return_srr)
 	andi.	r0,r5,MSR_RI
 	li	r3,0 /* 0 return value, no EMULATE_STACK_STORE */
 	bne+	.Lfast_kernel_interrupt_return_srr
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	unrecoverable_exception
 	b	. /* should not get here */
 #else
@@ -406,7 +406,7 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
 	beq	interrupt_return_\srr\()_kernel
 interrupt_return_\srr\()_user: /* make backtraces match the _kernel variant */
 _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_user)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	interrupt_exit_user_prepare
 	cmpdi	r3,0
 	bne-	.Lrestore_nvgprs_\srr
@@ -503,7 +503,7 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_user_restart)
 	GET_PACA(r13)
 	ld	r1,PACA_EXIT_SAVE_R1(r13)
 	LOAD_PACA_TOC()
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	li	r11,IRQS_ALL_DISABLED
 	stb	r11,PACAIRQSOFTMASK(r13)
 	bl	interrupt_exit_user_restart
@@ -518,7 +518,7 @@ RESTART_TABLE(.Linterrupt_return_\srr\()_user_rst_start, .Linterrupt_return_\srr
 	.balign IFETCH_ALIGN_BYTES
 interrupt_return_\srr\()_kernel:
 _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_kernel)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	bl	interrupt_exit_kernel_prepare
 
 	std	r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
@@ -684,7 +684,7 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_kernel_restart)
 	GET_PACA(r13)
 	ld	r1,PACA_EXIT_SAVE_R1(r13)
 	LOAD_PACA_TOC()
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 	li	r11,IRQS_ALL_DISABLED
 	stb	r11,PACAIRQSOFTMASK(r13)
 	bl	interrupt_exit_kernel_restart
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 1a1e9995dae3..ebe4d1645ca1 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -191,7 +191,7 @@ static int kgdb_break_match(struct pt_regs *regs)
 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
 {
 	struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp +
-						  STACK_FRAME_OVERHEAD);
+						  STACK_INT_FRAME_REGS);
 	unsigned long *ptr = gdb_regs;
 	int reg;
 
diff --git a/arch/powerpc/kernel/optprobes_head.S b/arch/powerpc/kernel/optprobes_head.S
index cd4e7bc32609..35932f45fb4e 100644
--- a/arch/powerpc/kernel/optprobes_head.S
+++ b/arch/powerpc/kernel/optprobes_head.S
@@ -85,7 +85,7 @@ optprobe_template_op_address:
 	TEMPLATE_FOR_IMM_LOAD_INSNS
 
 	/* 2. pt_regs pointer in r4 */
-	addi	r4,r1,STACK_FRAME_OVERHEAD
+	addi	r4,r1,STACK_INT_FRAME_REGS
 
 	.global optprobe_template_call_handler
 optprobe_template_call_handler:
@@ -96,7 +96,7 @@ optprobe_template_call_handler:
 	 * Parameters for instruction emulation:
 	 * 1. Pass SP in register r3.
 	 */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
+	addi	r3,r1,STACK_INT_FRAME_REGS
 
 	.global optprobe_template_insn
 optprobe_template_insn:
diff --git a/arch/powerpc/kernel/ppc_save_regs.S b/arch/powerpc/kernel/ppc_save_regs.S
index 6e86f3bf4673..49813f982468 100644
--- a/arch/powerpc/kernel/ppc_save_regs.S
+++ b/arch/powerpc/kernel/ppc_save_regs.S
@@ -22,7 +22,7 @@
  */
 _GLOBAL(ppc_save_regs)
 	/* This allows stack frame accessor macros and offsets to be used */
-	subi	r3,r3,STACK_FRAME_OVERHEAD
+	subi	r3,r3,STACK_INT_FRAME_REGS
 	PPC_STL	r0,GPR0(r3)
 #ifdef CONFIG_PPC32
 	stmw	r2,GPR2(r3)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index f93703ea4a12..d7a581997d92 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2260,12 +2260,12 @@ void __no_sanitize_address show_stack(struct task_struct *tsk,
 
 		/*
 		 * See if this is an exception frame.
-		 * We look for the "regshere" marker in the current frame.
+		 * We look for the "regs" marker in the current frame.
 		 */
 		if (validate_sp(sp, tsk, STACK_FRAME_WITH_PT_REGS)
 		    && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
 			struct pt_regs *regs = (struct pt_regs *)
-				(sp + STACK_FRAME_OVERHEAD);
+				(sp + STACK_INT_FRAME_REGS);
 
 			lr = regs->link;
 			printk("%s--- interrupt: %lx at %pS\n",
diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
index 5a0f023a26e9..9feab5e0485b 100644
--- a/arch/powerpc/kernel/tm.S
+++ b/arch/powerpc/kernel/tm.S
@@ -117,7 +117,7 @@ _GLOBAL(tm_reclaim)
 	std	r2, STK_GOT(r1)
 	stdu	r1, -TM_FRAME_SIZE(r1)
 
-	/* We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD]. */
+	/* We've a struct pt_regs at [r1+STACK_INT_FRAME_REGS]. */
 
 	std	r3, STK_PARAM(R3)(r1)
 	SAVE_NVGPRS(r1)
@@ -222,7 +222,7 @@ _GLOBAL(tm_reclaim)
 	 * Make r7 look like an exception frame so that we can use the neat
 	 * GPRx(n) macros. r7 is NOT a pt_regs ptr!
 	 */
-	subi	r7, r7, STACK_FRAME_OVERHEAD
+	subi	r7, r7, STACK_INT_FRAME_REGS
 
 	/* Sync the userland GPRs 2-12, 14-31 to thread->regs: */
 	SAVE_GPR(0, r7)				/* user r0 */
@@ -359,7 +359,7 @@ _GLOBAL(__tm_recheckpoint)
 	stdu	r1, -TM_FRAME_SIZE(r1)
 
 	/*
-	 * We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD].
+	 * We've a struct pt_regs at [r1+STACK_INT_FRAME_REGS].
 	 * This is used for backing up the NVGPRs:
 	 */
 	SAVE_NVGPRS(r1)
@@ -379,7 +379,7 @@ _GLOBAL(__tm_recheckpoint)
 	 * Make r7 look like an exception frame so that we can use the neat
 	 * GPRx(n) macros. r7 is now NOT a pt_regs ptr!
 	 */
-	subi	r7, r7, STACK_FRAME_OVERHEAD
+	subi	r7, r7, STACK_INT_FRAME_REGS
 
 	/* We need to setup MSR for FP/VMX/VSX register save instructions. */
 	mfmsr	r6
diff --git a/arch/powerpc/kernel/trace/ftrace_mprofile.S b/arch/powerpc/kernel/trace/ftrace_mprofile.S
index d031093bc436..ffb1db386849 100644
--- a/arch/powerpc/kernel/trace/ftrace_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_mprofile.S
@@ -110,7 +110,7 @@
 	.endif
 
 	/* Load &pt_regs in r6 for call below */
-	addi    r6, r1, STACK_FRAME_OVERHEAD
+	addi    r6, r1, STACK_INT_FRAME_REGS
 .endm
 
 .macro	ftrace_regs_exit allregs
diff --git a/arch/powerpc/lib/test_emulate_step_exec_instr.S b/arch/powerpc/lib/test_emulate_step_exec_instr.S
index 5473f9d03df3..e2b646a4f7fa 100644
--- a/arch/powerpc/lib/test_emulate_step_exec_instr.S
+++ b/arch/powerpc/lib/test_emulate_step_exec_instr.S
@@ -16,7 +16,7 @@ _GLOBAL(exec_instr)
 
 	/*
 	 * Stack frame layout (INT_FRAME_SIZE bytes)
-	 *   In-memory pt_regs	(SP + STACK_FRAME_OVERHEAD)
+	 *   In-memory pt_regs	(SP + STACK_INT_FRAME_REGS)
 	 *   Scratch space	(SP + 8)
 	 *   Back chain		(SP + 0)
 	 */
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index 8718289c051d..9e254aed1f61 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -67,7 +67,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
 			 * This looks like an interrupt frame for an
 			 * interrupt that occurred in the kernel
 			 */
-			regs = (struct pt_regs *)(sp + STACK_FRAME_OVERHEAD);
+			regs = (struct pt_regs *)(sp + STACK_INT_FRAME_REGS);
 			next_ip = regs->nip;
 			lr = regs->link;
 			level = 0;
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index e34d7809f6c9..a14eb4d815c2 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1782,14 +1782,13 @@ static void xmon_show_stack(unsigned long sp, unsigned long lr,
 			xmon_print_symbol(ip, " ", "\n");
 		}
 
-		/* Look for "regshere" marker to see if this is
+		/* Look for "regs" marker to see if this is
 		   an exception frame. */
 		if (mread(sp + MARKER_OFFSET, &marker, sizeof(unsigned long))
 		    && marker == STACK_FRAME_REGS_MARKER) {
-			if (mread(sp + STACK_FRAME_OVERHEAD, &regs, sizeof(regs))
-			    != sizeof(regs)) {
+			if (mread(sp + STACK_INT_FRAME_REGS, &regs, sizeof(regs)) != sizeof(regs)) {
 				printf("Couldn't read registers at %lx\n",
-				       sp + STACK_FRAME_OVERHEAD);
+				       sp + STACK_INT_FRAME_REGS);
 				break;
 			}
 			printf("--- Exception: %lx %s at ", regs.trap,
-- 
cgit v1.2.3


From e856e336924b0ecd0b7058e65e6b3e7266ee0b95 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:34 +1000
Subject: powerpc: Rename STACK_FRAME_MARKER and derive it from frame offset

This is a count of longs from the stack pointer to the regs marker.
Rename it to make it more distinct from the other byte offsets. It
can be derived from the byte offset definitions just added.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-10-npiggin@gmail.com
---
 arch/powerpc/include/asm/ptrace.h | 4 ++--
 arch/powerpc/kernel/process.c     | 2 +-
 arch/powerpc/kernel/stacktrace.c  | 2 +-
 arch/powerpc/perf/callchain.c     | 2 +-
 arch/powerpc/xmon/xmon.c          | 3 +--
 5 files changed, 6 insertions(+), 7 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 8a9f4cf8c4c5..fdd50648df56 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -126,7 +126,6 @@ struct pt_regs
 				 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)
 #define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_INT_FRAME_MARKER	(STACK_FRAME_OVERHEAD - 16)
-#define STACK_FRAME_MARKER	12
 
 #ifdef CONFIG_PPC64_ELF_ABI_V2
 #define STACK_FRAME_MIN_SIZE	32
@@ -147,7 +146,6 @@ struct pt_regs
 #define STACK_INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
 #define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_INT_FRAME_MARKER	(STACK_FRAME_OVERHEAD - 8)
-#define STACK_FRAME_MARKER	2
 #define STACK_FRAME_MIN_SIZE	STACK_FRAME_OVERHEAD
 
 /* Size of stack frame allocated when calling signal handler. */
@@ -155,6 +153,8 @@ struct pt_regs
 
 #endif /* __powerpc64__ */
 
+#define STACK_INT_FRAME_MARKER_LONGS	(STACK_INT_FRAME_MARKER/sizeof(long))
+
 #ifndef __ASSEMBLY__
 #include <asm/paca.h>
 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index d7a581997d92..6c0a3c664266 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2263,7 +2263,7 @@ void __no_sanitize_address show_stack(struct task_struct *tsk,
 		 * We look for the "regs" marker in the current frame.
 		 */
 		if (validate_sp(sp, tsk, STACK_FRAME_WITH_PT_REGS)
-		    && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+		    && stack[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) {
 			struct pt_regs *regs = (struct pt_regs *)
 				(sp + STACK_INT_FRAME_REGS);
 
diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index a2443d61728e..7efa0ec9dd77 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -136,7 +136,7 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum
 
 		/* Mark stacktraces with exception frames as unreliable. */
 		if (sp <= stack_end - STACK_INT_FRAME_SIZE &&
-		    stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+		    stack[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) {
 			return -EINVAL;
 		}
 
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index 9e254aed1f61..b01497ed5173 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -62,7 +62,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
 
 		if (next_sp == sp + STACK_INT_FRAME_SIZE &&
 		    validate_sp(sp, current, STACK_INT_FRAME_SIZE) &&
-		    fp[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+		    fp[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) {
 			/*
 			 * This looks like an interrupt frame for an
 			 * interrupt that occurred in the kernel
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index a14eb4d815c2..0da66bc4823d 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1721,7 +1721,6 @@ static void get_function_bounds(unsigned long pc, unsigned long *startp,
 }
 
 #define LRSAVE_OFFSET		(STACK_FRAME_LR_SAVE * sizeof(unsigned long))
-#define MARKER_OFFSET		(STACK_FRAME_MARKER * sizeof(unsigned long))
 
 static void xmon_show_stack(unsigned long sp, unsigned long lr,
 			    unsigned long pc)
@@ -1784,7 +1783,7 @@ static void xmon_show_stack(unsigned long sp, unsigned long lr,
 
 		/* Look for "regs" marker to see if this is
 		   an exception frame. */
-		if (mread(sp + MARKER_OFFSET, &marker, sizeof(unsigned long))
+		if (mread(sp + STACK_INT_FRAME_MARKER, &marker, sizeof(unsigned long))
 		    && marker == STACK_FRAME_REGS_MARKER) {
 			if (mread(sp + STACK_INT_FRAME_REGS, &regs, sizeof(regs)) != sizeof(regs)) {
 				printf("Couldn't read registers at %lx\n",
-- 
cgit v1.2.3


From 1223e5a20f7fb3c31c91a328d1a04ed26d5e889b Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:35 +1000
Subject: powerpc: add a define for the user interrupt frame size

The user interrupt frame is a different size from the kernel frame, so
give it its own name.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-11-npiggin@gmail.com
---
 arch/powerpc/include/asm/ptrace.h | 6 +++---
 arch/powerpc/kernel/process.c     | 6 +++---
 arch/powerpc/kernel/stacktrace.c  | 4 ++--
 3 files changed, 8 insertions(+), 8 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index fdd50648df56..705ce26ae887 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -122,8 +122,7 @@ struct pt_regs
 
 #define STACK_FRAME_OVERHEAD	112	/* size of minimum stack frame */
 #define STACK_FRAME_LR_SAVE	2	/* Location of LR in stack frame */
-#define STACK_INT_FRAME_SIZE	(sizeof(struct pt_regs) + \
-				 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)
+#define STACK_USER_INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
 #define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_INT_FRAME_MARKER	(STACK_FRAME_OVERHEAD - 16)
 
@@ -143,7 +142,7 @@ struct pt_regs
 #define KERNEL_REDZONE_SIZE	0
 #define STACK_FRAME_OVERHEAD	16	/* size of minimum stack frame */
 #define STACK_FRAME_LR_SAVE	1	/* Location of LR in stack frame */
-#define STACK_INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
+#define STACK_USER_INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
 #define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_INT_FRAME_MARKER	(STACK_FRAME_OVERHEAD - 8)
 #define STACK_FRAME_MIN_SIZE	STACK_FRAME_OVERHEAD
@@ -153,6 +152,7 @@ struct pt_regs
 
 #endif /* __powerpc64__ */
 
+#define STACK_INT_FRAME_SIZE	(KERNEL_REDZONE_SIZE + STACK_USER_INT_FRAME_SIZE)
 #define STACK_INT_FRAME_MARKER_LONGS	(STACK_INT_FRAME_MARKER/sizeof(long))
 
 #ifndef __ASSEMBLY__
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 6c0a3c664266..010a5ee746ae 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1756,15 +1756,15 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	klp_init_thread_info(p);
 
 	/* Create initial stack frame. */
-	sp -= (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD);
+	sp -= STACK_USER_INT_FRAME_SIZE;
 	((unsigned long *)sp)[0] = 0;
 
 	/* Copy registers */
-	childregs = (struct pt_regs *)(sp + STACK_FRAME_OVERHEAD);
+	childregs = (struct pt_regs *)(sp + STACK_INT_FRAME_REGS);
 	if (unlikely(args->fn)) {
 		/* kernel thread */
 		memset(childregs, 0, sizeof(struct pt_regs));
-		childregs->gpr[1] = sp + (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD);
+		childregs->gpr[1] = sp + STACK_USER_INT_FRAME_SIZE;
 		/* function */
 		if (args->fn)
 			childregs->gpr[14] = ppc_function_entry((void *)args->fn);
diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index 7efa0ec9dd77..453ac317a6cf 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -77,7 +77,7 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum
 		/*
 		 * For user tasks, this is the SP value loaded on
 		 * kernel entry, see "PACAKSAVE(r13)" in _switch() and
-		 * system_call_common()/EXCEPTION_PROLOG_COMMON().
+		 * system_call_common().
 		 *
 		 * Likewise for non-swapper kernel threads,
 		 * this also happens to be the top of the stack
@@ -88,7 +88,7 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum
 		 * an unreliable stack trace until it's been
 		 * _switch()'ed to for the first time.
 		 */
-		stack_end -= STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+		stack_end -= STACK_USER_INT_FRAME_SIZE;
 	} else {
 		/*
 		 * idle tasks have a custom stack layout,
-- 
cgit v1.2.3


From 6f291a03819e4051ebc870471d26915ef2e6ba31 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:36 +1000
Subject: powerpc: add a define for the switch frame size and regs offset

This is open-coded in process.c, ppc32 uses a different define with the
same value, and the C definition is name differently which makes it an
extra indirection to grep for.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-12-npiggin@gmail.com
---
 arch/powerpc/include/asm/ptrace.h |  6 ++++--
 arch/powerpc/kernel/asm-offsets.c |  2 +-
 arch/powerpc/kernel/entry_32.S    |  6 +++---
 arch/powerpc/kernel/process.c     | 12 ++++++++----
 4 files changed, 16 insertions(+), 10 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 705ce26ae887..412ef0749775 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -97,8 +97,6 @@ struct pt_regs
 #endif
 
 
-#define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs))
-
 // Always displays as "REGS" in memory dumps
 #ifdef CONFIG_CPU_BIG_ENDIAN
 #define STACK_FRAME_REGS_MARKER	ASM_CONST(0x52454753)
@@ -125,6 +123,8 @@ struct pt_regs
 #define STACK_USER_INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
 #define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_INT_FRAME_MARKER	(STACK_FRAME_OVERHEAD - 16)
+#define STACK_SWITCH_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
+#define STACK_SWITCH_FRAME_REGS	STACK_FRAME_OVERHEAD
 
 #ifdef CONFIG_PPC64_ELF_ABI_V2
 #define STACK_FRAME_MIN_SIZE	32
@@ -146,6 +146,8 @@ struct pt_regs
 #define STACK_INT_FRAME_REGS	STACK_FRAME_OVERHEAD
 #define STACK_INT_FRAME_MARKER	(STACK_FRAME_OVERHEAD - 8)
 #define STACK_FRAME_MIN_SIZE	STACK_FRAME_OVERHEAD
+#define STACK_SWITCH_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
+#define STACK_SWITCH_FRAME_REGS	STACK_FRAME_OVERHEAD
 
 /* Size of stack frame allocated when calling signal handler. */
 #define __SIGNAL_FRAMESIZE	64
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 68905c9f7c21..d24a59a98c0c 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -260,7 +260,7 @@ int main(void)
 
 	/* Interrupt register frame */
 	DEFINE(INT_FRAME_SIZE, STACK_INT_FRAME_SIZE);
-	DEFINE(SWITCH_FRAME_SIZE, STACK_FRAME_WITH_PT_REGS);
+	DEFINE(SWITCH_FRAME_SIZE, STACK_SWITCH_FRAME_SIZE);
 	STACK_PT_REGS_OFFSET(GPR0, gpr[0]);
 	STACK_PT_REGS_OFFSET(GPR1, gpr[1]);
 	STACK_PT_REGS_OFFSET(GPR2, gpr[2]);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 2f61b7d3677c..6e99ec10be89 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -215,9 +215,9 @@ ret_from_kernel_thread:
  * in arch/ppc/kernel/process.c
  */
 _GLOBAL(_switch)
-	stwu	r1,-INT_FRAME_SIZE(r1)
+	stwu	r1,-SWITCH_FRAME_SIZE(r1)
 	mflr	r0
-	stw	r0,INT_FRAME_SIZE+4(r1)
+	stw	r0,SWITCH_FRAME_SIZE+4(r1)
 	/* r3-r12 are caller saved -- Cort */
 	SAVE_NVGPRS(r1)
 	stw	r0,_NIP(r1)	/* Return to switch caller */
@@ -248,7 +248,7 @@ _GLOBAL(_switch)
 
 	lwz	r4,_NIP(r1)	/* Return to _switch caller in new task */
 	mtlr	r4
-	addi	r1,r1,INT_FRAME_SIZE
+	addi	r1,r1,SWITCH_FRAME_SIZE
 	blr
 
 	.globl	fast_exception_return
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 010a5ee746ae..0cb5296c6c41 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1808,10 +1808,10 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	 * do some house keeping and then return from the fork or clone
 	 * system call, using the stack frame created above.
 	 */
-	sp -= sizeof(struct pt_regs);
-	kregs = (struct pt_regs *) sp;
-	sp -= STACK_FRAME_OVERHEAD;
+	sp -= STACK_SWITCH_FRAME_SIZE;
+	kregs = (struct pt_regs *)(sp + STACK_SWITCH_FRAME_REGS);
 	p->thread.ksp = sp;
+
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	for (i = 0; i < nr_wp_slots(); i++)
 		p->thread.ptrace_bps[i] = NULL;
@@ -2261,8 +2261,12 @@ void __no_sanitize_address show_stack(struct task_struct *tsk,
 		/*
 		 * See if this is an exception frame.
 		 * We look for the "regs" marker in the current frame.
+		 *
+		 * STACK_SWITCH_FRAME_SIZE being the smallest frame that
+		 * could hold a pt_regs, if that does not fit then it can't
+		 * have regs.
 		 */
-		if (validate_sp(sp, tsk, STACK_FRAME_WITH_PT_REGS)
+		if (validate_sp(sp, tsk, STACK_SWITCH_FRAME_SIZE)
 		    && stack[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) {
 			struct pt_regs *regs = (struct pt_regs *)
 				(sp + STACK_INT_FRAME_REGS);
-- 
cgit v1.2.3


From 6895dfc0474170c492191c126fcfc420f7771a09 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:37 +1000
Subject: powerpc: copy_thread fill in interrupt frame marker and back chain

Backtraces will not recognise the fork system call interrupt without
the regs marker. And regular interrupt entry from userspace creates
the back chain to the user stack, so do this for the initial fork
frame too, to be consistent.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-13-npiggin@gmail.com
---
 arch/powerpc/kernel/process.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 0cb5296c6c41..6b1d80bd370e 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1757,12 +1757,13 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 
 	/* Create initial stack frame. */
 	sp -= STACK_USER_INT_FRAME_SIZE;
-	((unsigned long *)sp)[0] = 0;
+	*(unsigned long *)(sp + STACK_INT_FRAME_MARKER) = STACK_FRAME_REGS_MARKER;
 
 	/* Copy registers */
 	childregs = (struct pt_regs *)(sp + STACK_INT_FRAME_REGS);
 	if (unlikely(args->fn)) {
 		/* kernel thread */
+		((unsigned long *)sp)[0] = 0;
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->gpr[1] = sp + STACK_USER_INT_FRAME_SIZE;
 		/* function */
@@ -1782,6 +1783,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 		*childregs = *regs;
 		if (usp)
 			childregs->gpr[1] = usp;
+		((unsigned long *)sp)[0] = childregs->gpr[1];
 		p->thread.regs = childregs;
 		/* 64s sets this in ret_from_fork */
 		if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
-- 
cgit v1.2.3


From edbd0387f3249cc7e102f86d4852a9a9f3bb1305 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:38 +1000
Subject: powerpc: copy_thread add a back chain to the switch stack frame

Stack unwinders need LR and the back chain as a minimum. The switch
stack uses regs->nip for its return pointer rather than lrsave, so
that was not set in the fork frame, and neither was the back chain.
This change sets those fields in the stack.

With this and the previous change, a stack trace in the switch or
interrupt stack goes from looking like this:

  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 3 PID: 90 Comm: systemd Not tainted
  NIP:  c000000000011060 LR: c000000000010f68 CTR: 0000000000007fff
  [ ... regs ... ]
  NIP [c000000000011060] _switch+0x160/0x17c
  LR [c000000000010f68] _switch+0x68/0x17c
  Call Trace:

To this:

  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  CPU: 0 PID: 93 Comm: systemd Not tainted
  NIP:  c000000000011060 LR: c000000000010f68 CTR: 0000000000007fff
  [ ... regs ... ]
  NIP [c000000000011060] _switch+0x160/0x17c
  LR [c000000000010f68] _switch+0x68/0x17c
  Call Trace:
  [c000000005a93e10] [c00000000000cdbc] ret_from_fork_scv+0x0/0x54
  --- interrupt: 3000 at 0x7fffa72f56d8
  NIP:  00007fffa72f56d8 LR: 0000000000000000 CTR: 0000000000000000
  [ ... regs ... ]
  NIP [00007fffa72f56d8] 0x7fffa72f56d8
  LR [0000000000000000] 0x0
  --- interrupt: 3000

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-14-npiggin@gmail.com
---
 arch/powerpc/kernel/process.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 6b1d80bd370e..096b6ea52378 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1810,7 +1810,9 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	 * do some house keeping and then return from the fork or clone
 	 * system call, using the stack frame created above.
 	 */
+	((unsigned long *)sp)[STACK_FRAME_LR_SAVE] = (unsigned long)f;
 	sp -= STACK_SWITCH_FRAME_SIZE;
+	((unsigned long *)sp)[0] = sp + STACK_SWITCH_FRAME_SIZE;
 	kregs = (struct pt_regs *)(sp + STACK_SWITCH_FRAME_REGS);
 	p->thread.ksp = sp;
 
-- 
cgit v1.2.3


From 4cefb0f6c555971b3e6544a9b15470f9d1f12089 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:39 +1000
Subject: powerpc: split validate_sp into two functions

Most callers just want to validate an arbitrary kernel stack pointer,
some need a particular size. Make the size case the exceptional one
with an extra function.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-15-npiggin@gmail.com
---
 arch/powerpc/include/asm/processor.h | 15 ++++++++++++---
 arch/powerpc/kernel/process.c        | 23 ++++++++++++++---------
 arch/powerpc/kernel/stacktrace.c     |  2 +-
 arch/powerpc/perf/callchain.c        |  6 +++---
 4 files changed, 30 insertions(+), 16 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 631802999d59..e96c9b8c2a60 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -374,9 +374,18 @@ static inline unsigned long __pack_fe01(unsigned int fpmode)
 
 #endif
 
-/* Check that a certain kernel stack pointer is valid in task_struct p */
-int validate_sp(unsigned long sp, struct task_struct *p,
-                       unsigned long nbytes);
+/*
+ * Check that a certain kernel stack pointer is a valid (minimum sized)
+ * stack frame in task_struct p.
+ */
+int validate_sp(unsigned long sp, struct task_struct *p);
+
+/*
+ * validate the stack frame of a particular minimum size, used for when we are
+ * looking at a certain object in the stack beyond the minimum.
+ */
+int validate_sp_size(unsigned long sp, struct task_struct *p,
+		     unsigned long nbytes);
 
 /*
  * Prefetch macros.
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 096b6ea52378..9446bee8ca32 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2157,9 +2157,12 @@ static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p,
 	return 0;
 }
 
-
-int validate_sp(unsigned long sp, struct task_struct *p,
-		       unsigned long nbytes)
+/*
+ * validate the stack frame of a particular minimum size, used for when we are
+ * looking at a certain object in the stack beyond the minimum.
+ */
+int validate_sp_size(unsigned long sp, struct task_struct *p,
+		     unsigned long nbytes)
 {
 	unsigned long stack_page = (unsigned long)task_stack_page(p);
 
@@ -2175,7 +2178,10 @@ int validate_sp(unsigned long sp, struct task_struct *p,
 	return valid_emergency_stack(sp, p, nbytes);
 }
 
-EXPORT_SYMBOL(validate_sp);
+int validate_sp(unsigned long sp, struct task_struct *p)
+{
+	return validate_sp_size(sp, p, STACK_FRAME_OVERHEAD);
+}
 
 static unsigned long ___get_wchan(struct task_struct *p)
 {
@@ -2183,13 +2189,12 @@ static unsigned long ___get_wchan(struct task_struct *p)
 	int count = 0;
 
 	sp = p->thread.ksp;
-	if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
+	if (!validate_sp(sp, p))
 		return 0;
 
 	do {
 		sp = READ_ONCE_NOCHECK(*(unsigned long *)sp);
-		if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
-		    task_is_running(p))
+		if (!validate_sp(sp, p) || task_is_running(p))
 			return 0;
 		if (count > 0) {
 			ip = READ_ONCE_NOCHECK(((unsigned long *)sp)[STACK_FRAME_LR_SAVE]);
@@ -2243,7 +2248,7 @@ void __no_sanitize_address show_stack(struct task_struct *tsk,
 	lr = 0;
 	printk("%sCall Trace:\n", loglvl);
 	do {
-		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
+		if (!validate_sp(sp, tsk))
 			break;
 
 		stack = (unsigned long *) sp;
@@ -2270,7 +2275,7 @@ void __no_sanitize_address show_stack(struct task_struct *tsk,
 		 * could hold a pt_regs, if that does not fit then it can't
 		 * have regs.
 		 */
-		if (validate_sp(sp, tsk, STACK_SWITCH_FRAME_SIZE)
+		if (validate_sp_size(sp, tsk, STACK_SWITCH_FRAME_SIZE)
 		    && stack[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) {
 			struct pt_regs *regs = (struct pt_regs *)
 				(sp + STACK_INT_FRAME_REGS);
diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index 453ac317a6cf..1dbbf30f265e 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -43,7 +43,7 @@ void __no_sanitize_address arch_stack_walk(stack_trace_consume_fn consume_entry,
 		unsigned long *stack = (unsigned long *) sp;
 		unsigned long newsp, ip;
 
-		if (!validate_sp(sp, task, STACK_FRAME_OVERHEAD))
+		if (!validate_sp(sp, task))
 			return;
 
 		newsp = stack[0];
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index b01497ed5173..6b4434dd0ff3 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -27,7 +27,7 @@ static int valid_next_sp(unsigned long sp, unsigned long prev_sp)
 {
 	if (sp & 0xf)
 		return 0;		/* must be 16-byte aligned */
-	if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
+	if (!validate_sp(sp, current))
 		return 0;
 	if (sp >= prev_sp + STACK_FRAME_MIN_SIZE)
 		return 1;
@@ -53,7 +53,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
 	sp = regs->gpr[1];
 	perf_callchain_store(entry, perf_instruction_pointer(regs));
 
-	if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
+	if (!validate_sp(sp, current))
 		return;
 
 	for (;;) {
@@ -61,7 +61,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
 		next_sp = fp[0];
 
 		if (next_sp == sp + STACK_INT_FRAME_SIZE &&
-		    validate_sp(sp, current, STACK_INT_FRAME_SIZE) &&
+		    validate_sp_size(sp, current, STACK_INT_FRAME_SIZE) &&
 		    fp[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) {
 			/*
 			 * This looks like an interrupt frame for an
-- 
cgit v1.2.3


From 90f1b43196c5e79f6c986a359011a19857984c27 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Sun, 27 Nov 2022 22:49:40 +1000
Subject: powerpc: allow minimum sized kernel stack frames

This affects only 64-bit ELFv2 kernels, and reduces the minimum
asm-created stack frame size from 112 to 32 byte on those kernels.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-16-npiggin@gmail.com
---
 arch/powerpc/kernel/head_40x.S       | 2 +-
 arch/powerpc/kernel/head_44x.S       | 6 +++---
 arch/powerpc/kernel/head_64.S        | 6 +++---
 arch/powerpc/kernel/head_85xx.S      | 4 ++--
 arch/powerpc/kernel/head_8xx.S       | 2 +-
 arch/powerpc/kernel/head_book3s_32.S | 4 ++--
 arch/powerpc/kernel/irq.c            | 4 ++--
 arch/powerpc/kernel/misc_32.S        | 2 +-
 arch/powerpc/kernel/misc_64.S        | 4 ++--
 arch/powerpc/kernel/process.c        | 2 +-
 arch/powerpc/kernel/smp.c            | 2 +-
 arch/powerpc/kernel/stacktrace.c     | 2 +-
 12 files changed, 20 insertions(+), 20 deletions(-)

(limited to 'arch/powerpc/kernel/process.c')

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 088f500896c7..918547b93b5e 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -602,7 +602,7 @@ start_here:
 	lis	r1,init_thread_union@ha
 	addi	r1,r1,init_thread_union@l
 	li	r0,0
-	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
+	stwu	r0,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r1)
 
 	bl	early_init	/* We have to do this with MMU on */
 
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index f15cb9fdb692..63a85c16fef4 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -109,7 +109,7 @@ _GLOBAL(_start);
 	lis	r1,init_thread_union@h
 	ori	r1,r1,init_thread_union@l
 	li	r0,0
-	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
+	stwu	r0,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r1)
 
 	bl	early_init
 
@@ -1012,7 +1012,7 @@ _GLOBAL(start_secondary_47x)
 	 */
 	lis	r1,temp_boot_stack@h
 	ori	r1,r1,temp_boot_stack@l
-	addi	r1,r1,1024-STACK_FRAME_OVERHEAD
+	addi	r1,r1,1024-STACK_FRAME_MIN_SIZE
 	li	r0,0
 	stw	r0,0(r1)
 	bl	mmu_init_secondary
@@ -1025,7 +1025,7 @@ _GLOBAL(start_secondary_47x)
 	lwz	r1,TASK_STACK(r2)
 
 	/* Current stack pointer */
-	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+	addi	r1,r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE
 	li	r0,0
 	stw	r0,0(r1)
 
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index dedcc6fe2263..b513d13bf79e 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -424,7 +424,7 @@ generic_secondary_common_init:
 
 	/* Create a temp kernel stack for use before relocation is on.	*/
 	ld	r1,PACAEMERGSP(r13)
-	subi	r1,r1,STACK_FRAME_OVERHEAD
+	subi	r1,r1,STACK_FRAME_MIN_SIZE
 
 	/* See if we need to call a cpu state restore handler */
 	LOAD_REG_ADDR(r23, cur_cpu_spec)
@@ -780,7 +780,7 @@ _GLOBAL(pmac_secondary_start)
 
 	/* Create a temp kernel stack for use before relocation is on.	*/
 	ld	r1,PACAEMERGSP(r13)
-	subi	r1,r1,STACK_FRAME_OVERHEAD
+	subi	r1,r1,STACK_FRAME_MIN_SIZE
 
 	b	__secondary_start
 
@@ -958,7 +958,7 @@ start_here_multiplatform:
 	LOAD_REG_IMMEDIATE(r1,THREAD_SIZE)
 	add	r1,r3,r1
 	li	r0,0
-	stdu	r0,-STACK_FRAME_OVERHEAD(r1)
+	stdu	r0,-STACK_FRAME_MIN_SIZE(r1)
 
 	/*
 	 * Do very early kernel initializations, including initial hash table
diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S
index 24f39abf81df..d9bd377dec91 100644
--- a/arch/powerpc/kernel/head_85xx.S
+++ b/arch/powerpc/kernel/head_85xx.S
@@ -229,7 +229,7 @@ set_ivor:
 	lis	r1,init_thread_union@h
 	ori	r1,r1,init_thread_union@l
 	li	r0,0
-	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
+	stwu	r0,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r1)
 
 #ifdef CONFIG_SMP
 	stw	r24, TASK_CPU(r2)
@@ -1044,7 +1044,7 @@ __secondary_start:
 	lwz	r1,TASK_STACK(r2)
 
 	/* stack */
-	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+	addi	r1,r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE
 	li	r0,0
 	stw	r0,0(r1)
 
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 0b05f2be66b9..cf546d0e5c40 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -537,7 +537,7 @@ start_here:
 	ori	r0, r0, STACK_END_MAGIC@l
 	stw	r0, 0(r1)
 	li	r0,0
-	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
+	stwu	r0,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r1)
 
 	lis	r6, swapper_pg_dir@ha
 	tophys(r6,r6)
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 519b60695167..40854d092dd3 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -840,7 +840,7 @@ __secondary_start:
 	lwz	r1,TASK_STACK(r1)
 
 	/* stack */
-	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+	addi	r1,r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE
 	li	r0,0
 	tophys(r3,r1)
 	stw	r0,0(r3)
@@ -966,7 +966,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
 	lis	r1,init_thread_union@ha
 	addi	r1,r1,init_thread_union@l
 	li	r0,0
-	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
+	stwu	r0,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r1)
 /*
  * Do early platform-specific initialization,
  * and set up the MMU.
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 9ede61a5a469..c5b9ce887483 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -210,7 +210,7 @@ static __always_inline void call_do_softirq(const void *sp)
 		 PPC_LL "	%%r1, 0(%%r1)		;"
 		 : // Outputs
 		 : // Inputs
-		   [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
+		   [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE),
 		   [callee] "i" (__do_softirq)
 		 : // Clobbers
 		   "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
@@ -264,7 +264,7 @@ static __always_inline void call_do_irq(struct pt_regs *regs, void *sp)
 		 : // Outputs
 		   "+r" (r3)
 		 : // Inputs
-		   [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
+		   [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE),
 		   [callee] "i" (__do_irq)
 		 : // Clobbers
 		   "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index e5127b19fec2..daf8f87d2372 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -382,7 +382,7 @@ EXPORT_SYMBOL(__bswapdi2)
 _GLOBAL(start_secondary_resume)
 	/* Reset stack */
 	rlwinm	r1, r1, 0, 0, 31 - THREAD_SHIFT
-	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+	addi	r1,r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE
 	li	r3,0
 	stw	r3,0(r1)		/* Zero the stack frame pointer	*/
 	bl	start_secondary
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 36184cada00b..4bb6dd30c556 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -384,7 +384,7 @@ _GLOBAL(kexec_sequence)
 	std	r0,16(r1)
 
 	/* switch stacks to newstack -- &kexec_stack.stack */
-	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
+	stdu	r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r3)
 	mr	r1,r3
 
 	li	r0,0
@@ -401,7 +401,7 @@ _GLOBAL(kexec_sequence)
 	std	r26,-48(r1)
 	std	r25,-56(r1)
 
-	stdu	r1,-STACK_FRAME_OVERHEAD-64(r1)
+	stdu	r1,-STACK_FRAME_MIN_SIZE-64(r1)
 
 	/* save args into preserved regs */
 	mr	r31,r3			/* newstack (both) */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9446bee8ca32..edb46d0806ef 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2180,7 +2180,7 @@ int validate_sp_size(unsigned long sp, struct task_struct *p,
 
 int validate_sp(unsigned long sp, struct task_struct *p)
 {
-	return validate_sp_size(sp, p, STACK_FRAME_OVERHEAD);
+	return validate_sp_size(sp, p, STACK_FRAME_MIN_SIZE);
 }
 
 static unsigned long ___get_wchan(struct task_struct *p)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 0da6e59161cd..6b90f10a6c81 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1249,7 +1249,7 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 #ifdef CONFIG_PPC64
 	paca_ptrs[cpu]->__current = idle;
 	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
-				 THREAD_SIZE - STACK_FRAME_OVERHEAD;
+				 THREAD_SIZE - STACK_FRAME_MIN_SIZE;
 #endif
 	task_thread_info(idle)->cpu = cpu;
 	secondary_current = current_set[cpu] = idle;
diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index 1dbbf30f265e..5de8597eaab8 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -94,7 +94,7 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum
 		 * idle tasks have a custom stack layout,
 		 * c.f. cpu_idle_thread_init().
 		 */
-		stack_end -= STACK_FRAME_OVERHEAD;
+		stack_end -= STACK_FRAME_MIN_SIZE;
 	}
 
 	if (task == current)
-- 
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