From: Nicholas Piggin <npiggin@gmail•com>
To: linuxppc-dev@lists•ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail•com>
Subject: [RFC PATCH 14/19] powerpc: split validate_sp into two functions
Date: Mon, 31 Oct 2022 15:54:35 +1000 [thread overview]
Message-ID: <20221031055440.3594315-15-npiggin@gmail.com> (raw)
In-Reply-To: <20221031055440.3594315-1-npiggin@gmail.com>
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>
---
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(-)
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 6cb3982a11ef..b5defea32e75 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2128,9 +2128,12 @@ 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);
@@ -2146,7 +2149,10 @@ 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(sp, p, STACK_FRAME_OVERHEAD);
+}
static unsigned long ___get_wchan(struct task_struct *p)
{
@@ -2154,13 +2160,12 @@ 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]);
@@ -2214,7 +2219,7 @@ 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;
@@ -2241,7 +2246,7 @@ 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
--
2.37.2
next prev parent reply other threads:[~2022-10-31 6:08 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-31 5:54 [RFC PATCH 00/19] Remove STACK_FRAME_OVERHEAD Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 01/19] powerpc/perf: callchain validate kernel stack pointer bounds Nicholas Piggin
2022-11-04 13:10 ` Segher Boessenkool
2022-10-31 5:54 ` [RFC PATCH 02/19] powerpc: Rearrange copy_thread child stack creation Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 03/19] powerpc/64: Remove asm interrupt tracing call helpers Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 04/19] powerpc/pseries: hvcall stack frame overhead Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 05/19] powerpc/32: Use load and store multiple in GPR save/restore macros Nicholas Piggin
2022-11-03 8:26 ` Christophe Leroy
2022-11-07 12:45 ` Nicholas Piggin
2022-11-07 12:51 ` Christophe Leroy
2022-10-31 5:54 ` [RFC PATCH 06/19] powerpc: simplify ppc_save_regs Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 07/19] powerpc: add definition for pt_regs offset within an interrupt frame Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 08/19] powerpc: add a definition for the marker offset within the " Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 09/19] powerpc: Rename STACK_FRAME_MARKER and derive it from frame offset Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 10/19] powerpc: add a define for the user interrupt frame size Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 11/19] powerpc: add a define for the switch frame size and regs offset Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 12/19] powerpc: copy_thread fill in interrupt frame marker and back chain Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 13/19] powerpc: copy_thread add a back chain to the switch stack frame Nicholas Piggin
2022-10-31 5:54 ` Nicholas Piggin [this message]
2022-11-07 0:58 ` [RFC PATCH 14/19] powerpc: split validate_sp into two functions Russell Currey
2022-11-07 12:29 ` Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 15/19] powerpc: allow minimum sized kernel stack frames Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 16/19] powerpc/64: ELFv2 use minimal stack frames in int and switch frame sizes Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 17/19] powerpc: remove STACK_FRAME_OVERHEAD Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 18/19] powerpc: change stack marker memory operations to 32-bit Nicholas Piggin
2022-10-31 5:54 ` [RFC PATCH 19/19] powerpc/64: ELFv2 use reserved word in the stack frame for the regs marker Nicholas Piggin
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