From 640586f8af356096e084d69a9909d217852bde48 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 19 Nov 2020 17:02:21 +0100 Subject: powerpc/ptrace: Simplify gpr_get()/tm_cgpr_get() gpr_get() does membuf_write() twice to override pt_regs->msr in between. We can call membuf_write() once and change ->msr in the kernel buffer, this simplifies the code and the next fix. The patch adds a new simple helper, membuf_at(offs), it returns the new membuf which can be safely used after membuf_write(). Signed-off-by: Oleg Nesterov [mpe: Fixup some minor whitespace issues noticed by Christophe] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201119160221.GA5188@redhat.com --- include/linux/regset.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux') diff --git a/include/linux/regset.h b/include/linux/regset.h index c3403f328257..a00765f0e8cf 100644 --- a/include/linux/regset.h +++ b/include/linux/regset.h @@ -46,6 +46,18 @@ static inline int membuf_write(struct membuf *s, const void *v, size_t size) return s->left; } +static inline struct membuf membuf_at(const struct membuf *s, size_t offs) +{ + struct membuf n = *s; + + if (offs > n.left) + offs = n.left; + n.p += offs; + n.left -= offs; + + return n; +} + /* current s->p must be aligned for v; v must be a scalar */ #define membuf_store(s, v) \ ({ \ -- cgit