Commit 5d86456d authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: tidy fault code 



Tidying in preparation for the segfault register dumping patch which follows.

void * pointers are changed to union uml_pt_regs *.  This makes the types
match reality, except in arch_fixup, which is changed to operate on a union
uml_pt_regs.  This fixes a bug in the call from segv_handler, which passes a
union uml_pt_regs, to segv, which expects to pass a struct sigcontext to
arch_fixup.

Whitespace and other style fixes.

There's also a errno printk fix.

Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ccdddb57

arch/um/include/arch.h

+1 −1
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ 
#include "sysdep/ptrace.h"



extern void arch_check_bugs(void);

extern int arch_fixup(unsigned long address, void *sc_ptr);

extern int arch_fixup(unsigned long address, union uml_pt_regs *regs);

extern int arch_handle_signal(int sig, union uml_pt_regs *regs);



#endif

arch/um/include/kern_util.h

+1 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ extern unsigned long alloc_stack(int order, int atomic); 
extern int do_signal(void);

extern int is_stack_fault(unsigned long sp);

extern unsigned long segv(struct faultinfo fi, unsigned long ip,

			  int is_user, void *sc);

			  int is_user, union uml_pt_regs *regs);

extern int handle_page_fault(unsigned long address, unsigned long ip,

			     int is_write, int is_user, int *code_out);

extern void syscall_ready(void);

arch/um/kernel/trap.c

+18 −17
Original line number Diff line number Diff line
@@ -157,7 +157,8 @@ static void segv_handler(int sig, union uml_pt_regs *regs) 
 * the info in the regs. A pointer to the info then would

 * give us bad data!

 */

unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)

unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,

		   union uml_pt_regs *regs)

{

	struct siginfo si;

	void *catcher;
@@ -167,7 +168,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc) 


	if(!is_user && (address >= start_vm) && (address < end_vm)){

		flush_tlb_kernel_vm();

                return(0);

		return 0;

	}

	else if(current->mm == NULL)

		panic("Segfault with no mm");
@@ -183,15 +184,15 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc) 


	catcher = current->thread.fault_catcher;

	if(!err)

		return(0);

		return 0;

	else if(catcher != NULL){

		current->thread.fault_addr = (void *) address;

		do_longjmp(catcher, 1);

	}

	else if(current->thread.fault_addr != NULL)

		panic("fault_addr set but no fault catcher");

        else if(!is_user && arch_fixup(ip, sc))

		return(0);

	else if(!is_user && arch_fixup(ip, regs))

		return 0;



	if(!is_user)

		panic("Kernel mode fault at addr 0x%lx, ip 0x%lx",
@@ -214,7 +215,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc) 
		current->thread.arch.faultinfo = fi;

		force_sig_info(SIGSEGV, &si, current);

	}

	return(0);

	return 0;

}



void relay_signal(int sig, union uml_pt_regs *regs)

arch/um/os-Linux/skas/trap.c

+8 −9
Original line number Diff line number Diff line
@@ -18,10 +18,9 @@ 
void sig_handler_common_skas(int sig, void *sc_ptr)

{

	struct sigcontext *sc = sc_ptr;

	struct skas_regs *r;

	union uml_pt_regs *r;

	void (*handler)(int, union uml_pt_regs *);

	int save_errno = errno;

	int save_user;

	int save_user, save_errno = errno;



	/* This is done because to allow SIGSEGV to be delivered inside a SEGV

	 * handler.  This can happen in copy_user, and if SEGV is disabled,
@@ -31,13 +30,13 @@ void sig_handler_common_skas(int sig, void *sc_ptr) 
	if(sig == SIGSEGV)

		change_sig(SIGSEGV, 1);



	r = &TASK_REGS(get_current())->skas;

	save_user = r->is_user;

	r->is_user = 0;

	r = TASK_REGS(get_current());

	save_user = r->skas.is_user;

	r->skas.is_user = 0;

	if ( sig == SIGFPE || sig == SIGSEGV ||

	     sig == SIGBUS || sig == SIGILL ||

	     sig == SIGTRAP ) {

		GET_FAULTINFO_FROM_SC(r->faultinfo, sc);

		GET_FAULTINFO_FROM_SC(r->skas.faultinfo, sc);

	}



	change_sig(SIGUSR1, 1);
@@ -49,10 +48,10 @@ void sig_handler_common_skas(int sig, void *sc_ptr) 
	    sig != SIGVTALRM && sig != SIGALRM)

		unblock_signals();



	handler(sig, (union uml_pt_regs *) r);

	handler(sig, r);



	errno = save_errno;

	r->is_user = save_user;

	r->skas.is_user = save_user;

}



extern int ptrace_faultinfo;

arch/um/sys-i386/fault.c

+2 −16
Original line number Diff line number Diff line
@@ -3,9 +3,7 @@ 
 * Licensed under the GPL

 */



#include <signal.h>

#include "sysdep/ptrace.h"

#include "sysdep/sigcontext.h"



/* These two are from asm-um/uaccess.h and linux/module.h, check them. */

struct exception_table_entry
@@ -17,26 +15,14 @@ struct exception_table_entry 
const struct exception_table_entry *search_exception_tables(unsigned long add);



/* Compare this to arch/i386/mm/extable.c:fixup_exception() */

int arch_fixup(unsigned long address, void *sc_ptr)

int arch_fixup(unsigned long address, union uml_pt_regs *regs)

{

	struct sigcontext *sc = sc_ptr;

	const struct exception_table_entry *fixup;



	fixup = search_exception_tables(address);

	if(fixup != 0){

		sc->eip = fixup->fixup;

		UPT_IP(regs) = fixup->fixup;

		return(1);

	}

	return(0);

}
 


/*

 * Overrides for Emacs so that we follow Linus's tabbing style.

 * Emacs will notice this stuff at the end of the file and automatically

 * adjust the settings for this buffer only.  This must remain at the end

 * of the file.

 * ---------------------------------------------------------------------------

 * Local variables:

 * c-file-style: "linux"

 * End:

 */

CRA Git | Maintained and supported by SUSTech CRA and CCSE