diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2022-08-08 16:09:45 +0100 |
|---|---|---|
| committer | Dinh Nguyen <dinguyen@kernel.org> | 2022-08-15 11:25:32 -0500 |
| commit | fd0c153daad135d0ec1a53c5dbe6936a724d6ae1 (patch) | |
| tree | 1b0b0486639eba2a2233205735ba09681a8864e0 /arch/nios2 | |
| parent | 411a76b7219555c55867466c82d70ce928d6c9e1 (diff) | |
nios2: add force_successful_syscall_return()
If we use the ancient SysV syscall ABI, we'd better have tell the
kernel how to claim that a negative return value is a success.
Use ->orig_r2 for that - it's inaccessible via ptrace, so it's
a fair game for changes and it's normally[*] non-negative on return
from syscall. Set to -1; syscall is not going to be restart-worthy
by definition, so we won't interfere with that use either.
[*] the only exception is rt_sigreturn(), where we skip the entire
messing with r1/r2 anyway.
Fixes: 82ed08dd1b0e ("nios2: Exception handling")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Diffstat (limited to 'arch/nios2')
| -rw-r--r-- | arch/nios2/include/asm/ptrace.h | 2 | ||||
| -rw-r--r-- | arch/nios2/kernel/entry.S | 6 |
2 files changed, 8 insertions, 0 deletions
diff --git a/arch/nios2/include/asm/ptrace.h b/arch/nios2/include/asm/ptrace.h index 642462144872..9da34c3022a2 100644 --- a/arch/nios2/include/asm/ptrace.h +++ b/arch/nios2/include/asm/ptrace.h @@ -74,6 +74,8 @@ extern void show_regs(struct pt_regs *); ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE)\ - 1) +#define force_successful_syscall_return() (current_pt_regs()->orig_r2 = -1) + int do_syscall_trace_enter(void); void do_syscall_trace_exit(void); #endif /* __ASSEMBLY__ */ diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S index fd2449031d08..99f0a65e6234 100644 --- a/arch/nios2/kernel/entry.S +++ b/arch/nios2/kernel/entry.S @@ -213,6 +213,9 @@ local_restart: translate_rc_and_ret: movi r1, 0 bge r2, zero, 3f + ldw r1, PT_ORIG_R2(sp) + addi r1, r1, 1 + beq r1, zero, 3f sub r2, zero, r2 movi r1, 1 3: @@ -276,6 +279,9 @@ traced_system_call: translate_rc_and_ret2: movi r1, 0 bge r2, zero, 4f + ldw r1, PT_ORIG_R2(sp) + addi r1, r1, 1 + beq r1, zero, 4f sub r2, zero, r2 movi r1, 1 4: |