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authorRich Felker <dalias@aerifal.cx>2015-09-23 18:33:49 +0000
committerRich Felker <dalias@aerifal.cx>2015-09-23 18:33:49 +0000
commitb61df2294f662540786f2558f691eba7447ff5ba (patch)
tree097e5fc922c4379fe7291f9381fa4fb0b79c1228
parent6c5cad2aa56745302c1d42d2c8baf6424d29c0f3 (diff)
downloadmusl-b61df2294f662540786f2558f691eba7447ff5ba.tar.gz
fix signal return for sh/fdpic
the restorer function pointer provided in the kernel sigaction structure is interpreted by the kernel as a raw code address, not a function descriptor. this commit moves the declarations of the __restore and __restore_rt symbols to ksigaction.h so that arch versions of the file can override them, and introduces a version for sh which declares them as objects rather than functions. an alternate solution would have been defining SA_RESTORER to 0 so that the functions are not used, but this both requires executable stack (since the sh kernel does not have a vdso page with permanent restorer functions) and crashes on qemu user-level emulation.
-rw-r--r--arch/mips/ksigaction.h2
-rw-r--r--arch/sh/ksigaction.h8
-rw-r--r--src/internal/ksigaction.h2
-rw-r--r--src/signal/sh/restore.s2
-rw-r--r--src/signal/sigaction.c2
5 files changed, 12 insertions, 4 deletions
diff --git a/arch/mips/ksigaction.h b/arch/mips/ksigaction.h
index 6d731646..3127f7c0 100644
--- a/arch/mips/ksigaction.h
+++ b/arch/mips/ksigaction.h
@@ -7,3 +7,5 @@ struct k_sigaction {
* mips-specific preprocessor conditionals in sigaction.c. */
void (*restorer)();
};
+
+void __restore(), __restore_rt();
diff --git a/arch/sh/ksigaction.h b/arch/sh/ksigaction.h
new file mode 100644
index 00000000..0c652bea
--- /dev/null
+++ b/arch/sh/ksigaction.h
@@ -0,0 +1,8 @@
+struct k_sigaction {
+ void (*handler)(int);
+ unsigned long flags;
+ void *restorer;
+ unsigned mask[2];
+};
+
+extern unsigned char __restore[], __restore_rt[];
diff --git a/src/internal/ksigaction.h b/src/internal/ksigaction.h
index 2eacabf1..1d8d9646 100644
--- a/src/internal/ksigaction.h
+++ b/src/internal/ksigaction.h
@@ -7,3 +7,5 @@ struct k_sigaction {
void (*restorer)(void);
unsigned mask[2];
};
+
+void __restore(), __restore_rt();
diff --git a/src/signal/sh/restore.s b/src/signal/sh/restore.s
index eaedcdfb..d5df8e14 100644
--- a/src/signal/sh/restore.s
+++ b/src/signal/sh/restore.s
@@ -1,5 +1,4 @@
.global __restore
-.type __restore, @function
__restore:
mov #119, r3 !__NR_sigreturn
trapa #31
@@ -11,7 +10,6 @@ __restore:
or r0, r0
.global __restore_rt
-.type __restore_rt, @function
__restore_rt:
mov #100, r3 !__NR_rt_sigreturn
add #73, r3
diff --git a/src/signal/sigaction.c b/src/signal/sigaction.c
index d5f47741..ab23a6f2 100644
--- a/src/signal/sigaction.c
+++ b/src/signal/sigaction.c
@@ -6,8 +6,6 @@
#include "libc.h"
#include "ksigaction.h"
-void __restore(), __restore_rt();
-
static int unmask_done;
static unsigned long handler_set[_NSIG/(8*sizeof(long))];