Re: [PATCH] riscv: Rename "sp_in_global" to "current_stack_pointer"
From: Palmer Dabbelt
Date: Tue Mar 22 2022 - 22:16:36 EST
On Wed, 23 Feb 2022 22:04:11 PST (-0800), keescook@xxxxxxxxxxxx wrote:
To follow the existing per-arch conventions, rename "sp_in_global" to
"current_stack_pointer". This will let it be used in non-arch places
(like HARDENED_USERCOPY).
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Jisheng Zhang <jszhang@xxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Chen Huang <chenhuang5@xxxxxxxxxx>
Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/current.h | 2 ++
arch/riscv/kernel/stacktrace.c | 4 +---
3 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5adcbd9b5e88..b120c32697af 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -16,6 +16,7 @@ config RISCV
select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
select ARCH_HAS_BINFMT_FLAT
+ select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEBUG_VIRTUAL if MMU
select ARCH_HAS_DEBUG_WX
diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h
index 1de233d8e8de..21774d868c65 100644
--- a/arch/riscv/include/asm/current.h
+++ b/arch/riscv/include/asm/current.h
@@ -33,6 +33,8 @@ static __always_inline struct task_struct *get_current(void)
#define current get_current()
+register unsigned long current_stack_pointer __asm__("sp");
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_RISCV_CURRENT_H */
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 201ee206fb57..278380e2e956 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -14,8 +14,6 @@
#include <asm/stacktrace.h>
-register unsigned long sp_in_global __asm__("sp");
-
#ifdef CONFIG_FRAME_POINTER
void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
@@ -77,7 +75,7 @@ void notrace walk_stackframe(struct task_struct *task,
sp = user_stack_pointer(regs);
pc = instruction_pointer(regs);
} else if (task == NULL || task == current) {
- sp = sp_in_global;
+ sp = current_stack_pointer;
pc = (unsigned long)walk_stackframe;
} else {
/* task blocked in __switch_to */
Sorry to be slow on this one. This looks good, but another use of
sp_in_global snuck into fixes and I don't merge fixes into for-next so
that makes this a bit of a headache.
There's a bunch of stuff in flight, so I'm going to hold off on this
until after my first week's merge window PR. I intend on merging the
following, which is at palmer/riscv-sp for now (I'll probably just
cherry-pick that, I usually start basing stuff on Linus' merge of my PR
and just cherry-pick in single patches).
commit 7c4f6bb6fb352cfa6028191c2888356b9157a332
gpg: Signature made Tue 22 Mar 2022 11:12:19 AM PDT
gpg: using RSA key 2B3C3747446843B24A943A7A2E1319F35FBB1889
gpg: issuer "palmer@xxxxxxxxxxx"
gpg: Good signature from "Palmer Dabbelt <palmer@xxxxxxxxxxx>" [ultimate]
gpg: aka "Palmer Dabbelt <palmer@xxxxxxxxxxxx>" [ultimate]
Author: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Wed Feb 23 22:04:11 2022 -0800
riscv: Rename "sp_in_global" to "current_stack_pointer"
To follow the existing per-arch conventions, rename "sp_in_global" to
"current_stack_pointer". This will let it be used in non-arch places
(like HARDENED_USERCOPY).
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5adcbd9b5e88..b120c32697af 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -16,6 +16,7 @@ config RISCV
select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
select ARCH_HAS_BINFMT_FLAT
+ select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEBUG_VIRTUAL if MMU
select ARCH_HAS_DEBUG_WX
diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h
index 1de233d8e8de..21774d868c65 100644
--- a/arch/riscv/include/asm/current.h
+++ b/arch/riscv/include/asm/current.h
@@ -33,6 +33,8 @@ static __always_inline struct task_struct *get_current(void)
#define current get_current()
+register unsigned long current_stack_pointer __asm__("sp");
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_RISCV_CURRENT_H */
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 14d2b53ec322..08d11a53f39e 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -14,8 +14,6 @@
#include <asm/stacktrace.h>
-register unsigned long sp_in_global __asm__("sp");
-
#ifdef CONFIG_FRAME_POINTER
void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
@@ -30,7 +28,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
pc = instruction_pointer(regs);
} else if (task == NULL || task == current) {
fp = (unsigned long)__builtin_frame_address(0);
- sp = sp_in_global;
+ sp = current_stack_pointer;
pc = (unsigned long)walk_stackframe;
} else {
/* task blocked in __switch_to */
@@ -78,7 +76,7 @@ void notrace walk_stackframe(struct task_struct *task,
sp = user_stack_pointer(regs);
pc = instruction_pointer(regs);
} else if (task == NULL || task == current) {
- sp = sp_in_global;
+ sp = current_stack_pointer;
pc = (unsigned long)walk_stackframe;
} else {
/* task blocked in __switch_to */
Thanks!