From: Christophe Leroy <christophe.leroy@c-s.fr> To: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au> Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2 1/3] powerpc/irq: don't use current_stack_pointer() in check_stack_overflow() Date: Fri, 24 Jan 2020 07:07:52 +0000 (UTC) [thread overview] Message-ID: <435e0030e942507766cbef5bc95f906262d2ccf2.1579849665.git.christophe.leroy@c-s.fr> (raw) current_stack_pointer() doesn't return the stack pointer, but the caller's stack frame. See commit bfe9a2cfe91a ("powerpc: Reimplement __get_SP() as a function not a define") and commit acf620ecf56c ("powerpc: Rename __get_SP() to current_stack_pointer()") for details. The purpose of check_stack_overflow() is to verify that the stack has not overflowed. To really know whether the stack pointer is still within boundaries, the check must be done directly on the value of r1. Define a get_sp() macro to get the value of r1 directly. (Adapted from arch/powerpc/boot/reg.h) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- v2: Define a get_sp() macro instead of using asm("r1") locally. --- arch/powerpc/include/asm/reg.h | 3 +++ arch/powerpc/kernel/irq.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 1aa46dff0957..d585f2566338 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1450,6 +1450,9 @@ static inline void mtsrin(u32 val, u32 idx) extern unsigned long current_stack_pointer(void); +register unsigned long __stack_pointer asm("r1"); +#define get_sp() (__stack_pointer) + extern unsigned long scom970_read(unsigned int address); extern void scom970_write(unsigned int address, unsigned long value); diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index add67498c126..cd29c2eb2d8e 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -601,7 +601,7 @@ static inline void check_stack_overflow(void) #ifdef CONFIG_DEBUG_STACKOVERFLOW long sp; - sp = current_stack_pointer() & (THREAD_SIZE-1); + sp = get_sp() & (THREAD_SIZE - 1); /* check for stack overflow: is there less than 2KB free? */ if (unlikely(sp < 2048)) { -- 2.25.0
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@c-s.fr> To: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/3] powerpc/irq: don't use current_stack_pointer() in check_stack_overflow() Date: Fri, 24 Jan 2020 07:07:52 +0000 (UTC) [thread overview] Message-ID: <435e0030e942507766cbef5bc95f906262d2ccf2.1579849665.git.christophe.leroy@c-s.fr> (raw) current_stack_pointer() doesn't return the stack pointer, but the caller's stack frame. See commit bfe9a2cfe91a ("powerpc: Reimplement __get_SP() as a function not a define") and commit acf620ecf56c ("powerpc: Rename __get_SP() to current_stack_pointer()") for details. The purpose of check_stack_overflow() is to verify that the stack has not overflowed. To really know whether the stack pointer is still within boundaries, the check must be done directly on the value of r1. Define a get_sp() macro to get the value of r1 directly. (Adapted from arch/powerpc/boot/reg.h) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- v2: Define a get_sp() macro instead of using asm("r1") locally. --- arch/powerpc/include/asm/reg.h | 3 +++ arch/powerpc/kernel/irq.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 1aa46dff0957..d585f2566338 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1450,6 +1450,9 @@ static inline void mtsrin(u32 val, u32 idx) extern unsigned long current_stack_pointer(void); +register unsigned long __stack_pointer asm("r1"); +#define get_sp() (__stack_pointer) + extern unsigned long scom970_read(unsigned int address); extern void scom970_write(unsigned int address, unsigned long value); diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index add67498c126..cd29c2eb2d8e 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -601,7 +601,7 @@ static inline void check_stack_overflow(void) #ifdef CONFIG_DEBUG_STACKOVERFLOW long sp; - sp = current_stack_pointer() & (THREAD_SIZE-1); + sp = get_sp() & (THREAD_SIZE - 1); /* check for stack overflow: is there less than 2KB free? */ if (unlikely(sp < 2048)) { -- 2.25.0
next reply other threads:[~2020-01-24 7:07 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-24 7:07 Christophe Leroy [this message] 2020-01-24 7:07 ` [PATCH v2 1/3] powerpc/irq: don't use current_stack_pointer() in check_stack_overflow() Christophe Leroy 2020-01-24 7:07 ` [PATCH v2 2/3] powerpc/irq: use IS_ENABLED() " Christophe Leroy 2020-01-24 7:07 ` Christophe Leroy 2020-01-24 7:07 ` [PATCH v2 3/3] powerpc/irq: don't use current_stack_pointer() in do_IRQ() Christophe Leroy 2020-01-24 7:07 ` Christophe Leroy
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