Commit 0c1d1917 authored by Chris Metcalf's avatar Chris Metcalf
Browse files

tile: support simulator notification for ET_DYN objects 



The tile code notifies the simulator of new ET_EXEC objects starting
to execute so that tracing code can properly annotate the objects.
However, we didn't support ET_DYN executables like ld.so, so we
didn't properly load symbols, etc.  This change enables that support;
we use a variant of the SIM_CONTROL_DLOPEN simulator notification
that newer simulators will recognize and use to set the base address
for the next SIM_CONTROL_OS_EXEC notification.

Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
parent 70d2b595

arch/tile/mm/elf.c

+48 −14
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 
#include <asm/pgtable.h>

#include <asm/pgalloc.h>

#include <asm/sections.h>

#include <arch/sim_def.h>

#include <arch/sim.h>



/* Notify a running simulator, if any, that an exec just occurred. */

static void sim_notify_exec(const char *binary_name)
@@ -38,21 +38,55 @@ static void sim_notify_exec(const char *binary_name) 


static int notify_exec(struct mm_struct *mm)

{

	int retval = 0;  /* failure */



	if (mm->exe_file) {

		char *buf = (char *) __get_free_page(GFP_KERNEL);

		if (buf) {

			char *path = d_path(&mm->exe_file->f_path,

					    buf, PAGE_SIZE);

			if (!IS_ERR(path)) {

				sim_notify_exec(path);

				retval = 1;

	char *buf, *path;

	struct vm_area_struct *vma;



	if (!sim_is_simulator())

		return 1;



	if (mm->exe_file == NULL)

		return 0;



	for (vma = current->mm->mmap; ; vma = vma->vm_next) {

		if (vma == NULL)

			return 0;

		if (vma->vm_file == mm->exe_file)

			break;

	}



	buf = (char *) __get_free_page(GFP_KERNEL);

	if (buf == NULL)

		return 0;



	path = d_path(&mm->exe_file->f_path, buf, PAGE_SIZE);

	if (IS_ERR(path)) {

		free_page((unsigned long)buf);

		return 0;

	}



	/*

	 * Notify simulator of an ET_DYN object so we know the load address.

	 * The somewhat cryptic overuse of SIM_CONTROL_DLOPEN allows us

	 * to be backward-compatible with older simulator releases.

	 */

	if (vma->vm_start == (ELF_ET_DYN_BASE & PAGE_MASK)) {

		char buf[64];

		int i;



		snprintf(buf, sizeof(buf), "0x%lx:@", vma->vm_start);

		for (i = 0; ; ++i) {

			char c = buf[i];

			__insn_mtspr(SPR_SIM_CONTROL,

				     (SIM_CONTROL_DLOPEN

				      | (c << _SIM_CONTROL_OPERATOR_BITS)));

			if (c == '\0')

				break;

		}

	return retval;

	}



	sim_notify_exec(path);

	free_page((unsigned long)buf);

	return 1;

}



/* Notify a running simulator, if any, that we loaded an interpreter. */

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