From b4e9c9549f62329d2412f899635fddc5212b9cd4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 1 Jun 2020 19:42:40 -0400 Subject: introduction of regset ->get() wrappers, switching ELF coredumps to those Two new helpers: given a process and regset, dump into a buffer. regset_get() takes a buffer and size, regset_get_alloc() takes size and allocates a buffer. Return value in both cases is the amount of data actually dumped in case of success or -E... on error. In both cases the size is capped by regset->n * regset->size, so ->get() is called with offset 0 and size no more than what regset expects. binfmt_elf.c callers of ->get() are switched to using those; the other caller (copy_regset_to_user()) will need some preparations to switch. Signed-off-by: Al Viro --- kernel/regset.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 kernel/regset.c (limited to 'kernel/regset.c') diff --git a/kernel/regset.c b/kernel/regset.c new file mode 100644 index 000000000000..6b39fa0993ec --- /dev/null +++ b/kernel/regset.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include + +static int __regset_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int size, + void **data) +{ + void *p = *data, *to_free = NULL; + int res; + + if (!regset->get) + return -EOPNOTSUPP; + if (size > regset->n * regset->size) + size = regset->n * regset->size; + if (!p) { + to_free = p = kzalloc(size, GFP_KERNEL); + if (!p) + return -ENOMEM; + } + res = regset->get(target, regset, 0, size, p, NULL); + if (unlikely(res < 0)) { + kfree(to_free); + return res; + } + *data = p; + if (regset->get_size) { // arm64-only kludge, will go away + unsigned max_size = regset->get_size(target, regset); + if (size > max_size) + size = max_size; + } + return size; +} + +int regset_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int size, + void *data) +{ + return __regset_get(target, regset, size, &data); +} +EXPORT_SYMBOL(regset_get); + +int regset_get_alloc(struct task_struct *target, + const struct user_regset *regset, + unsigned int size, + void **data) +{ + *data = NULL; + return __regset_get(target, regset, size, data); +} +EXPORT_SYMBOL(regset_get_alloc); -- cgit v1.2.3