summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAl Viro <viro@zeniv.linux.org.uk>2022-08-08 17:09:45 +0200
committerDinh Nguyen <dinguyen@kernel.org>2022-08-15 18:25:32 +0200
commitfd0c153daad135d0ec1a53c5dbe6936a724d6ae1 (patch)
tree1b0b0486639eba2a2233205735ba09681a8864e0
parentnios2: restarts apply only to the first sigframe we build... (diff)
downloadlinux-fd0c153daad135d0ec1a53c5dbe6936a724d6ae1.tar.xz
linux-fd0c153daad135d0ec1a53c5dbe6936a724d6ae1.zip
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>
-rw-r--r--arch/nios2/include/asm/ptrace.h2
-rw-r--r--arch/nios2/kernel/entry.S6
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: