This patch does two things:
First, register as a listener on bpf_copy_to_kernel()
Second, in order that the hooked bpf-prog can call the sleepable kfuncs,
bpf_handle_pefile and bpf_post_handle_pefile are marked as
KF_SLEEPABLE.
Signed-off-by: Pingfan Liu <pi...@redhat.com>
Cc: Alexei Starovoitov <a...@kernel.org>
Cc: Philipp Rudo <pr...@redhat.com>
Cc: Baoquan He <b...@redhat.com>
Cc: Dave Young <dyo...@redhat.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: b...@vger.kernel.org
To: ke...@lists.infradead.org
---
kernel/kexec_pe_image.c | 67 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 67 insertions(+)
diff --git a/kernel/kexec_pe_image.c b/kernel/kexec_pe_image.c
index b0cf9942e68d2..f8debcde6b516 100644
--- a/kernel/kexec_pe_image.c
+++ b/kernel/kexec_pe_image.c
@@ -38,6 +38,51 @@ static struct kexec_res parsed_resource[3] = {
{ KEXEC_RES_CMDLINE_NAME, },
};
+/*
+ * @name should be one of : kernel, initrd, cmdline
+ */
+static int bpf_kexec_carrier(const char *name, struct mem_range_result *r)
+{
+ struct kexec_res *res;
+ int i;
+
+ if (!r || !name)
+ return -EINVAL;
+
+ for (i = 0; i < 3; i++) {
+ if (!strcmp(parsed_resource[i].name, name))
+ break;
+ }
+ if (i >= 3)
+ return -EINVAL;
+
+ res = &parsed_resource[i];
+ /*
+ * Replace the intermediate resource generated by the previous step.
+ */
+ if (!!res->r)
+ mem_range_result_put(res->r);
+ mem_range_result_get(r);
+ res->r = r;
+ return 0;
+}
+
+static struct carrier_listener kexec_res_listener[3] = {
+ { .name = KEXEC_RES_KERNEL_NAME,
+ .alloc_type = 1,
+ .handler = bpf_kexec_carrier,
+ },
+ { .name = KEXEC_RES_INITRD_NAME,
+ .alloc_type = 1,
+ .handler = bpf_kexec_carrier,
+ },
+ { .name = KEXEC_RES_CMDLINE_NAME,
+ /* kmalloc-ed */
+ .alloc_type = 0,
+ .handler = bpf_kexec_carrier,
+ },
+};
+
static bool pe_has_bpf_section(const char *file_buf, unsigned long pe_sz);
static bool is_valid_pe(const char *kernel_buf, unsigned long kernel_len)
@@ -159,6 +204,22 @@ __attribute__((used, optimize("O0"))) void
bpf_post_handle_pefile(struct kexec_c
dummy += 2;
}
+BTF_KFUNCS_START(kexec_modify_return_ids)
+BTF_ID_FLAGS(func, bpf_handle_pefile, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_post_handle_pefile, KF_SLEEPABLE)
+BTF_KFUNCS_END(kexec_modify_return_ids)
+
+static const struct btf_kfunc_id_set kexec_modify_return_set = {
+ .owner = THIS_MODULE,
+ .set = &kexec_modify_return_ids,
+};
+
+static int __init kexec_bpf_prog_run_init(void)
+{
+ return register_btf_fmodret_id_set(&kexec_modify_return_set);
+}
+late_initcall(kexec_bpf_prog_run_init);
+
/*
* PE file may be nested and should be unfold one by one.
* Query 'kernel', 'initrd', 'cmdline' in cur_phase, as they are inputs for the
@@ -213,6 +274,9 @@ static void *pe_image_load(struct kimage *image,
cmdline_start = cmdline;
cmdline_sz = cmdline_len;
+ for (int i = 0; i < ARRAY_SIZE(kexec_res_listener); i++)
+ register_carrier_listener(&kexec_res_listener[i]);
+
while (is_valid_format(linux_start, linux_sz) &&
pe_has_bpf_section(linux_start, linux_sz)) {
struct kexec_context context;
@@ -250,6 +314,9 @@ static void *pe_image_load(struct kimage *image,
disarm_bpf_prog();
}
+ for (int i = 0; i < ARRAY_SIZE(kexec_res_listener); i++)
+ unregister_carrier_listener(kexec_res_listener[i].name);
+
/*
* image's kernel_buf, initrd_buf, cmdline_buf are set. Now they should
* be updated to the new content.
--
2.49.0
