diff options
authorRich Felker <>2015-09-22 20:51:59 +0000
committerRich Felker <>2015-09-22 20:51:59 +0000
commite9e770dfd6224a5ff7932b6115a35005dce7be29 (patch)
parentc87a52103399135d2f57a91a8bcc749d8cb2ca83 (diff)
have sh/fdpic entry point set fdpic personality if needed
the entry point code supports being loaded by a loader which is not fdpic-aware (in practice, either kernel with mmu or qemu without fdpic support). this mostly just works, but signal handling will wrongly use a function descriptor address as a code address if the personality is not adjusted to fdpic. ideally this code could be placed with sigaction so that it's not needed except if/when a signal handler is installed. however, personality is incorrectly maintained per-thread by the kernel, rather than per-process, so it's necessary to correct the personality before any threads are started. also, in order to skip the personality syscall when an fdpic-aware loader is used, we need to be able to detect how the program was loaded, and this information is only readily available at the entry point.
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/sh/crt_arch.h b/arch/sh/crt_arch.h
index d63ce0d1..948bcb79 100644
--- a/arch/sh/crt_arch.h
+++ b/arch/sh/crt_arch.h
@@ -4,6 +4,18 @@ __asm__(
".text \n"
".global " START " \n"
START ": \n"
+" tst r8, r8 \n"
+" bf 1f \n"
+" mov #68, r3 \n"
+" add r3, r3 \n"
+" mov #8, r4 \n"
+" swap.w r4, r4 \n"
+" trapa #31 \n"
+" nop \n"
+" nop \n"
+" nop \n"
+" nop \n"
+"1: nop \n"
#ifndef SHARED
" mov r8, r4 \n"
" mova 1f, r0 \n"