[RFC PATCH 15/19] powerpc: allow minimum sized kernel stack frames
Nicholas Piggin
npiggin at gmail.com
Mon Oct 31 16:54:36 AEDT 2022
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 at 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(-)
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 at ha
addi r1,r1,init_thread_union at 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 at h
ori r1,r1,init_thread_union at 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 at h
ori r1,r1,temp_boot_stack at 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 at h
ori r1,r1,init_thread_union at 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 at 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 at 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 at ha
addi r1,r1,init_thread_union at 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 b5defea32e75..20fdb84759f0 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2151,7 +2151,7 @@ int validate_sp_size(unsigned long sp, struct task_struct *p,
int validate_sp(unsigned long sp, struct task_struct *p)
{
- return validate_sp(sp, p, STACK_FRAME_OVERHEAD);
+ return validate_sp(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)
--
2.37.2
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