i386 vsyscall DSO implementation, take 2

@@ -19,6 +19,7 @@
 #include <linux/stddef.h>
 #include <linux/personality.h>
 #include <linux/suspend.h>
+#include <linux/elf.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>

@@ -347,6 +348,10 @@ get_sigframe(struct k_sigaction *ka, str
 	return (void __user *)((esp - frame_size) & -8ul);
 }
 
+/* These symbols are defined with the addresses in the vsyscall page.
+   See vsyscall-sigreturn.S.  */
+extern void __kernel_sigreturn, __kernel_rt_sigreturn;
+
 static void setup_frame(int sig, struct k_sigaction *ka,
 			sigset_t *set, struct pt_regs * regs)
 {

@@ -379,7 +384,7 @@ static void setup_frame(int sig, struct 
 	if (err)
 		goto give_sigsegv;
 
-	restorer = (void *) (fix_to_virt(FIX_VSYSCALL) + 32);
+	restorer = &__kernel_sigreturn;
 	if (ka->sa.sa_flags & SA_RESTORER)
 		restorer = ka->sa.sa_restorer;
 

@@ -462,7 +467,7 @@ static void setup_rt_frame(int sig, stru
 		goto give_sigsegv;
 
 	/* Set up to return from userspace.  */
-	restorer = (void *) (fix_to_virt(FIX_VSYSCALL) + 64);
+	restorer = &__kernel_rt_sigreturn;
 	if (ka->sa.sa_flags & SA_RESTORER)
 		restorer = ka->sa.sa_restorer;
 	err |= __put_user(restorer, &frame->pretcode);

168 lines not on this page · raw message

@@ -1260,6 +1260,9 @@ static int elf_core_dump(long signr, str
 	elf_core_copy_regs(&prstatus->pr_reg, regs);
 	
 	segs = current->mm->map_count;
+#ifdef ELF_CORE_EXTRA_PHDRS
+	segs += ELF_CORE_EXTRA_PHDRS;
+#endif
 
 	/* Set up header */
 	fill_elf_header(elf, segs+1);	/* including notes section */

@@ -1340,6 +1343,10 @@ static int elf_core_dump(long signr, str
 		DUMP_WRITE(&phdr, sizeof(phdr));
 	}
 
+#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
+	ELF_CORE_WRITE_EXTRA_PHDRS;
+#endif
+
  	/* write out the notes section */
 	for (i = 0; i < numnote; i++)
 		if (!writenote(notes + i, file))

@@ -1385,6 +1392,10 @@ static int elf_core_dump(long signr, str
 		}
 	}
 
+#ifdef ELF_CORE_WRITE_EXTRA_DATA
+	ELF_CORE_WRITE_EXTRA_DATA;
+#endif
+
 	if ((off_t) file->f_pos != offset) {
 		/* Sanity check */
 		printk("elf_core_dump: file->f_pos (%ld) != offset (%ld)\n",

@@ -29,8 +29,11 @@ typedef __s64	Elf64_Sxword;
 #define PT_NOTE    4
 #define PT_SHLIB   5
 #define PT_PHDR    6
+#define PT_LOOS	   0x60000000
+#define PT_HIOS	   0x6fffffff
 #define PT_LOPROC  0x70000000
 #define PT_HIPROC  0x7fffffff
+#define PT_GNU_EH_FRAME		0x6474e550
 #define PT_MIPS_REGINFO		0x70000000
 
 /* Flags in the e_flags field of the header */

70 lines not on this page · raw message

diff -Nru a/arch/i386/kernel/asm-offsets.c b/arch/i386/kernel/asm-offsets.c
@@ -0,0 +1,31 @@
+/*
+ * Generate definitions needed by assembly language modules.
+ * This code generates raw asm output which is post-processed
+ * to extract and format the required data.
+ */
+
+#include <linux/signal.h>
+#include <asm/ucontext.h>
+#include "sigframe.h"
+
+#define DEFINE(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+
+#define BLANK() asm volatile("\n->" : : )
+
+void foo(void)
+{
+	DEFINE(SIGCONTEXT_eax, offsetof (struct sigcontext, eax));
+	DEFINE(SIGCONTEXT_ebx, offsetof (struct sigcontext, ebx));
+	DEFINE(SIGCONTEXT_ecx, offsetof (struct sigcontext, ecx));
+	DEFINE(SIGCONTEXT_edx, offsetof (struct sigcontext, edx));
+	DEFINE(SIGCONTEXT_esi, offsetof (struct sigcontext, esi));
+	DEFINE(SIGCONTEXT_edi, offsetof (struct sigcontext, edi));
+	DEFINE(SIGCONTEXT_ebp, offsetof (struct sigcontext, ebp));
+	DEFINE(SIGCONTEXT_esp, offsetof (struct sigcontext, esp));
+	DEFINE(SIGCONTEXT_eip, offsetof (struct sigcontext, eip));
+	BLANK();
+
+	DEFINE(RT_SIGFRAME_sigcontext,
+	       offsetof (struct rt_sigframe, uc.uc_mcontext));
+}

diff -Nru a/arch/i386/kernel/sigframe.h b/arch/i386/kernel/sigframe.h
@@ -0,0 +1,21 @@
+struct sigframe
+{
+	char *pretcode;
+	int sig;
+	struct sigcontext sc;
+	struct _fpstate fpstate;
+	unsigned long extramask[_NSIG_WORDS-1];
+	char retcode[8];
+};
+
+struct rt_sigframe
+{
+	char *pretcode;
+	int sig;
+	struct siginfo *pinfo;
+	void *puc;
+	struct siginfo info;
+	struct ucontext uc;
+	struct _fpstate fpstate;
+	char retcode[8];
+};

diff -Nru a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c
@@ -23,6 +23,7 @@
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
+#include "sigframe.h"
 
 #define DEBUG_SIG 0
 

@@ -125,28 +126,6 @@
 /*
  * Do a signal return; undo the signal stack.
  */
-
-struct sigframe
-{
-	char *pretcode;
-	int sig;
-	struct sigcontext sc;
-	struct _fpstate fpstate;
-	unsigned long extramask[_NSIG_WORDS-1];
-	char retcode[8];
-};
-
-struct rt_sigframe
-{
-	char *pretcode;
-	int sig;
-	struct siginfo *pinfo;
-	void *puc;
-	struct siginfo info;
-	struct ucontext uc;
-	struct _fpstate fpstate;
-	char retcode[8];
-};
 
 static int
 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax)