From: Sergei Trofimovich slyfox@gentoo.org
[ Upstream commit 61bf318eac2c13356f7bd1c6a05421ef504ccc8a ]
In https://bugs.gentoo.org/769614 Dmitry noticed that `ptrace(PTRACE_GET_SYSCALL_INFO)` does not return error sign properly.
The bug is in mismatch between get/set errors:
static inline long syscall_get_error(struct task_struct *task, struct pt_regs *regs) { return regs->r10 == -1 ? regs->r8:0; }
static inline long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs) { return regs->r8; }
static inline void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val) { if (error) { /* error < 0, but ia64 uses > 0 return value */ regs->r8 = -error; regs->r10 = -1; } else { regs->r8 = val; regs->r10 = 0; } }
Tested on v5.10 on rx3600 machine (ia64 9040 CPU).
Link: https://lkml.kernel.org/r/20210221002554.333076-2-slyfox@gentoo.org Link: https://bugs.gentoo.org/769614 Signed-off-by: Sergei Trofimovich slyfox@gentoo.org Reported-by: Dmitry V. Levin ldv@altlinux.org Reviewed-by: Dmitry V. Levin ldv@altlinux.org Cc: John Paul Adrian Glaubitz glaubitz@physik.fu-berlin.de Cc: Oleg Nesterov oleg@redhat.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/ia64/include/asm/syscall.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/ia64/include/asm/syscall.h b/arch/ia64/include/asm/syscall.h index 1d0b875fec44..ec909eec0b4c 100644 --- a/arch/ia64/include/asm/syscall.h +++ b/arch/ia64/include/asm/syscall.h @@ -35,7 +35,7 @@ static inline void syscall_rollback(struct task_struct *task, static inline long syscall_get_error(struct task_struct *task, struct pt_regs *regs) { - return regs->r10 == -1 ? regs->r8:0; + return regs->r10 == -1 ? -regs->r8:0; }
static inline long syscall_get_return_value(struct task_struct *task,