linux-user: Introduce imgsrc_read, imgsrc_read_alloc

Introduced and initialized, but not yet really used.
These will tidy the current tests vs BPRM_BUF_SIZE.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 52 insertions, 9 deletions

diff --git a/linux-user/loader.h b/linux-user/loader.h
index 324e5c872a..da6591fff0 100644
--- a/linux-user/loader.h
+++ b/linux-user/loader.h
@@ -18,6 +18,48 @@
 #ifndef LINUX_USER_LOADER_H
 #define LINUX_USER_LOADER_H
 
+typedef struct {
+    const void *cache;
+    unsigned int cache_size;
+    int fd;
+} ImageSource;
+
+/**
+ * imgsrc_read: Read from ImageSource
+ * @dst: destination for read
+ * @offset: offset within file for read
+ * @len: size of the read
+ * @img: ImageSource to read from
+ * @errp: Error details.
+ *
+ * Read into @dst, using the cache when possible.
+ */
+bool imgsrc_read(void *dst, off_t offset, size_t len,
+                 const ImageSource *img, Error **errp);
+
+/**
+ * imgsrc_read_alloc: Read from ImageSource
+ * @offset: offset within file for read
+ * @size: size of the read
+ * @img: ImageSource to read from
+ * @errp: Error details.
+ *
+ * Read into newly allocated memory, using the cache when possible.
+ */
+void *imgsrc_read_alloc(off_t offset, size_t len,
+                        const ImageSource *img, Error **errp);
+
+/**
+ * imgsrc_mmap: Map from ImageSource
+ *
+ * If @src has a file descriptor, pass on to target_mmap.  Otherwise,
+ * this is "mapping" from a host buffer, which resolves to memcpy.
+ * Therefore, flags must be MAP_PRIVATE | MAP_FIXED; the argument is
+ * retained for clarity.
+ */
+abi_long imgsrc_mmap(abi_ulong start, abi_ulong len, int prot,
+                     int flags, const ImageSource *src, abi_ulong offset);
+
 /*
  * Read a good amount of data initially, to hopefully get all the
  * program headers loaded.
@@ -29,15 +71,16 @@
  * used when loading binaries.
  */
 struct linux_binprm {
-        char buf[BPRM_BUF_SIZE] __attribute__((aligned));
-        abi_ulong p;
-        int fd;
-        int e_uid, e_gid;
-        int argc, envc;
-        char **argv;
-        char **envp;
-        char *filename;        /* Name of binary */
-        int (*core_dump)(int, const CPUArchState *); /* coredump routine */
+    char buf[BPRM_BUF_SIZE] __attribute__((aligned));
+    ImageSource src;
+    abi_ulong p;
+    int fd;
+    int e_uid, e_gid;
+    int argc, envc;
+    char **argv;
+    char **envp;
+    char *filename;        /* Name of binary */
+    int (*core_dump)(int, const CPUArchState *); /* coredump routine */
 };
 
 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);