linux-user: Create vdso_sigreturn_region_{start,end}

These variables will be populated from the vdso, and used
for detecting whether we are executing the sigreturn.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 26c090c95d3e90ad4a23a927267e4106f68975b0..28f0909d1a41cc23e4bebe91c1957279ada0d0af 100644 (file)
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1659,6 +1659,11 @@ static void load_elf_vdso(struct image_info *info, const VdsoImageInfo *vdso)
     if (vdso->rt_sigreturn_ofs) {
         default_rt_sigreturn = load_addr + vdso->rt_sigreturn_ofs;
     }
+    if (vdso->sigreturn_region_start_ofs) {
+        vdso_sigreturn_region_start =
+            load_addr + vdso->sigreturn_region_start_ofs;
+        vdso_sigreturn_region_end = load_addr + vdso->sigreturn_region_end_ofs;
+    }
 
     /* Remove write from VDSO segment. */
     target_mprotect(info->start_data, info->end_data - info->start_data,

diff --git a/linux-user/gen-vdso-elfn.c.inc b/linux-user/gen-vdso-elfn.c.inc
index b47019e136c4505398ce691d6051b73879a7b76b..c2677a146c6799a888760abc267d054f761f0ad7 100644 (file)
--- a/linux-user/gen-vdso-elfn.c.inc
+++ b/linux-user/gen-vdso-elfn.c.inc
@@ -84,9 +84,12 @@ static void elfN(search_symtab)(ElfN(Shdr) *shdr, unsigned sym_idx,
 
         if (sigreturn_sym && strcmp(sigreturn_sym, name) == 0) {
             sigreturn_addr = sym.st_value;
-        }
-        if (rt_sigreturn_sym && strcmp(rt_sigreturn_sym, name) == 0) {
+        } else if (rt_sigreturn_sym && strcmp(rt_sigreturn_sym, name) == 0) {
             rt_sigreturn_addr = sym.st_value;
+        } else if (strcmp("sigreturn_region_start", name) == 0) {
+            sigreturn_region_start_addr = sym.st_value;
+        } else if (strcmp("sigreturn_region_end", name) == 0) {
+            sigreturn_region_end_addr = sym.st_value;
         }
     }
 }

diff --git a/linux-user/gen-vdso.c b/linux-user/gen-vdso.c
index aeaa927db8fc99a08de2a0a6bebeb71ba45d4042..d6a2cdaa835cce38bb4d53f79f8f007c759fa4bc 100644 (file)
--- a/linux-user/gen-vdso.c
+++ b/linux-user/gen-vdso.c
@@ -36,6 +36,8 @@ static const char *rt_sigreturn_sym;
 
 static unsigned sigreturn_addr;
 static unsigned rt_sigreturn_addr;
+static unsigned sigreturn_region_start_addr;
+static unsigned sigreturn_region_end_addr;
 
 #define N 32
 #define elfN(x)  elf32_##x
@@ -215,6 +217,10 @@ int main(int argc, char **argv)
     fprintf(outf, "    .reloc_count = ARRAY_SIZE(%s_relocs),\n", prefix);
     fprintf(outf, "    .sigreturn_ofs = 0x%x,\n", sigreturn_addr);
     fprintf(outf, "    .rt_sigreturn_ofs = 0x%x,\n", rt_sigreturn_addr);
+    fprintf(outf, "    .sigreturn_region_start_ofs = 0x%x,\n",
+            sigreturn_region_start_addr);
+    fprintf(outf, "    .sigreturn_region_end_ofs = 0x%x,\n",
+            sigreturn_region_end_addr);
     fprintf(outf, "};\n");
 
     ret = EXIT_SUCCESS;

diff --git a/linux-user/loader.h b/linux-user/loader.h
index e42b8fa1e30f378b903b62182233b2a5ee1ed0e1..da9ad28db5de509ac87a702a662e55ef3c109728 100644 (file)
--- a/linux-user/loader.h
+++ b/linux-user/loader.h
@@ -117,6 +117,8 @@ typedef struct {
     unsigned reloc_count;
     unsigned sigreturn_ofs;
     unsigned rt_sigreturn_ofs;
+    unsigned sigreturn_region_start_ofs;
+    unsigned sigreturn_region_end_ofs;
 } VdsoImageInfo;
 
 /* Note that both Elf32_Word and Elf64_Word are uint32_t. */

diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h
index 196d2406f86eefe78398fdd72eebea200b2b26b5..0b04868727ed6525d1461de917b85de296b0676c 100644 (file)
--- a/linux-user/signal-common.h
+++ b/linux-user/signal-common.h
@@ -25,6 +25,8 @@
 /* Fallback addresses into sigtramp page. */
 extern abi_ulong default_sigreturn;
 extern abi_ulong default_rt_sigreturn;
+extern abi_ulong vdso_sigreturn_region_start;
+extern abi_ulong vdso_sigreturn_region_end;
 
 void setup_sigtramp(abi_ulong tramp_page);
 

diff --git a/linux-user/signal.c b/linux-user/signal.c
index cd0e7398aa46a6e2cef36170fa51ac895fdcf965..804096bd4470b38ee678754e509beab9b692d1ff 100644 (file)
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -50,6 +50,8 @@ static void host_signal_handler(int host_signum, siginfo_t *info,
 /* Fallback addresses into sigtramp page. */
 abi_ulong default_sigreturn;
 abi_ulong default_rt_sigreturn;
+abi_ulong vdso_sigreturn_region_start;
+abi_ulong vdso_sigreturn_region_end;
 
 /*
  * System includes define _NSIG as SIGRTMAX + 1, but qemu (like the kernel)