6.6-stable review patch. If anyone has any objections, please let me know.
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From: Max Filippov jcmvbkbc@gmail.com
commit 0e60f0b75884677fb9f4f2ad40d52b43451564d5 upstream.
Xtensa has two-argument MAKE_PC_FROM_RA macro to convert a0 to an actual return address because when windowed ABI is used call{,x}{4,8,12} opcodes stuff encoded window size into the top 2 bits of the register that becomes a return address in the called function. Second argument of that macro is supposed to be an address having these 2 topmost bits set correctly, but the comment suggested that that could be the stack address. However the stack doesn't have to be in the same 1GByte region as the code, especially in noMMU XIP configurations.
Fix the comment and use either _text or regs->pc as the second argument for the MAKE_PC_FROM_RA macro.
Cc: stable@vger.kernel.org Signed-off-by: Max Filippov jcmvbkbc@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/xtensa/include/asm/processor.h | 8 ++++---- arch/xtensa/include/asm/ptrace.h | 2 +- arch/xtensa/kernel/process.c | 5 +++-- arch/xtensa/kernel/stacktrace.c | 3 ++- 4 files changed, 10 insertions(+), 8 deletions(-)
--- a/arch/xtensa/include/asm/processor.h +++ b/arch/xtensa/include/asm/processor.h @@ -115,9 +115,9 @@ #define MAKE_RA_FOR_CALL(ra,ws) (((ra) & 0x3fffffff) | (ws) << 30)
/* Convert return address to a valid pc - * Note: We assume that the stack pointer is in the same 1GB ranges as the ra + * Note: 'text' is the address within the same 1GB range as the ra */ -#define MAKE_PC_FROM_RA(ra,sp) (((ra) & 0x3fffffff) | ((sp) & 0xc0000000)) +#define MAKE_PC_FROM_RA(ra, text) (((ra) & 0x3fffffff) | ((unsigned long)(text) & 0xc0000000))
#elif defined(__XTENSA_CALL0_ABI__)
@@ -127,9 +127,9 @@ #define MAKE_RA_FOR_CALL(ra, ws) (ra)
/* Convert return address to a valid pc - * Note: We assume that the stack pointer is in the same 1GB ranges as the ra + * Note: 'text' is not used as 'ra' is always the full address */ -#define MAKE_PC_FROM_RA(ra, sp) (ra) +#define MAKE_PC_FROM_RA(ra, text) (ra)
#else #error Unsupported Xtensa ABI --- a/arch/xtensa/include/asm/ptrace.h +++ b/arch/xtensa/include/asm/ptrace.h @@ -87,7 +87,7 @@ struct pt_regs { # define user_mode(regs) (((regs)->ps & 0x00000020)!=0) # define instruction_pointer(regs) ((regs)->pc) # define return_pointer(regs) (MAKE_PC_FROM_RA((regs)->areg[0], \ - (regs)->areg[1])) + (regs)->pc))
# ifndef CONFIG_SMP # define profile_pc(regs) instruction_pointer(regs) --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -47,6 +47,7 @@ #include <asm/asm-offsets.h> #include <asm/regs.h> #include <asm/hw_breakpoint.h> +#include <asm/sections.h> #include <asm/traps.h>
extern void ret_from_fork(void); @@ -380,7 +381,7 @@ unsigned long __get_wchan(struct task_st int count = 0;
sp = p->thread.sp; - pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp); + pc = MAKE_PC_FROM_RA(p->thread.ra, _text);
do { if (sp < stack_page + sizeof(struct task_struct) || @@ -392,7 +393,7 @@ unsigned long __get_wchan(struct task_st
/* Stack layout: sp-4: ra, sp-3: sp' */
- pc = MAKE_PC_FROM_RA(SPILL_SLOT(sp, 0), sp); + pc = MAKE_PC_FROM_RA(SPILL_SLOT(sp, 0), _text); sp = SPILL_SLOT(sp, 1); } while (count++ < 16); return 0; --- a/arch/xtensa/kernel/stacktrace.c +++ b/arch/xtensa/kernel/stacktrace.c @@ -13,6 +13,7 @@ #include <linux/stacktrace.h>
#include <asm/ftrace.h> +#include <asm/sections.h> #include <asm/stacktrace.h> #include <asm/traps.h> #include <linux/uaccess.h> @@ -189,7 +190,7 @@ void walk_stackframe(unsigned long *sp, if (a1 <= (unsigned long)sp) break;
- frame.pc = MAKE_PC_FROM_RA(a0, a1); + frame.pc = MAKE_PC_FROM_RA(a0, _text); frame.sp = a1;
if (fn(&frame, data))