xtensa: expose syscall through user_pt_regs

Use one of the reserved slots in struct user_pt_regs to return syscall
number in the GPR regset. Update syscall number from the GPR regset only
when it's non-zero.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2020-07-18 17:47:43 -07:00
parent ef1a935c08
commit 8b7a87a03f
2 changed files with 6 additions and 1 deletions

View file

@ -50,7 +50,8 @@ struct user_pt_regs {
__u32 windowstart;
__u32 windowbase;
__u32 threadptr;
__u32 reserved[7 + 48];
__u32 syscall;
__u32 reserved[6 + 48];
__u32 a[64];
};

View file

@ -52,6 +52,7 @@ static int gpr_get(struct task_struct *target,
.threadptr = regs->threadptr,
.windowbase = regs->windowbase,
.windowstart = regs->windowstart,
.syscall = regs->syscall,
};
memcpy(newregs.a,
@ -91,6 +92,9 @@ static int gpr_set(struct task_struct *target,
regs->sar = newregs.sar;
regs->threadptr = newregs.threadptr;
if (newregs.syscall)
regs->syscall = newregs.syscall;
if (newregs.windowbase != regs->windowbase ||
newregs.windowstart != regs->windowstart) {
u32 rotws, wmask;