Commit 9fc84914 authored by Michael Ellerman's avatar Michael Ellerman
Browse files

Merge branch 'topic/kprobes' into next 

Although most of these kprobes patches are powerpc specific, there's a couple
that touch generic code (with Acks). At the moment there's one conflict with
acme's tree, but it's not too bad. Still just in case some other conflicts show
up, we've put these in a topic branch so another tree could merge some or all of
it if necessary.
parents 9a914aa6 24bd909e

Documentation/features/debug/kprobes-on-ftrace/arch-support.txt

+1 −1
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ 
    |       nios2: | TODO |

    |    openrisc: | TODO |

    |      parisc: | TODO |

    |     powerpc: | TODO |

    |     powerpc: |  ok  |

    |        s390: | TODO |

    |       score: | TODO |

    |          sh: | TODO |

arch/powerpc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ config PPC 
	select HAVE_IRQ_EXIT_ON_IRQ_STACK

	select HAVE_KERNEL_GZIP

	select HAVE_KPROBES

	select HAVE_KPROBES_ON_FTRACE

	select HAVE_KRETPROBES

	select HAVE_LIVEPATCH			if HAVE_DYNAMIC_FTRACE_WITH_REGS

	select HAVE_MEMBLOCK

arch/powerpc/include/asm/code-patching.h

+41 −0
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 


#include <asm/types.h>

#include <asm/ppc-opcode.h>

#include <linux/string.h>

#include <linux/kallsyms.h>



/* Flags for create_branch:

 * "b"   == create_branch(addr, target, 0);
@@ -99,6 +101,45 @@ static inline unsigned long ppc_global_function_entry(void *func) 
#endif

}



/*

 * Wrapper around kallsyms_lookup() to return function entry address:

 * - For ABIv1, we lookup the dot variant.

 * - For ABIv2, we return the local entry point.

 */

static inline unsigned long ppc_kallsyms_lookup_name(const char *name)

{

	unsigned long addr;

#ifdef PPC64_ELF_ABI_v1

	/* check for dot variant */

	char dot_name[1 + KSYM_NAME_LEN];

	bool dot_appended = false;



	if (strnlen(name, KSYM_NAME_LEN) >= KSYM_NAME_LEN)

		return 0;



	if (name[0] != '.') {

		dot_name[0] = '.';

		dot_name[1] = '\0';

		strlcat(dot_name, name, sizeof(dot_name));

		dot_appended = true;

	} else {

		dot_name[0] = '\0';

		strlcat(dot_name, name, sizeof(dot_name));

	}

	addr = kallsyms_lookup_name(dot_name);

	if (!addr && dot_appended)

		/* Let's try the original non-dot symbol lookup	*/

		addr = kallsyms_lookup_name(name);

#elif defined(PPC64_ELF_ABI_v2)

	addr = kallsyms_lookup_name(name);

	if (addr)

		addr = ppc_function_entry((void *)addr);

#else

	addr = kallsyms_lookup_name(name);

#endif

	return addr;

}



#ifdef CONFIG_PPC64

/*

 * Some instruction encodings commonly used in dynamic ftracing

arch/powerpc/include/asm/kprobes.h

+10 −53
Original line number Diff line number Diff line
@@ -61,59 +61,6 @@ extern kprobe_opcode_t optprobe_template_end[]; 
#define MAX_OPTINSN_SIZE	(optprobe_template_end - optprobe_template_entry)

#define RELATIVEJUMP_SIZE	sizeof(kprobe_opcode_t)	/* 4 bytes */



#ifdef PPC64_ELF_ABI_v2

/* PPC64 ABIv2 needs local entry point */

#define kprobe_lookup_name(name, addr)					\

{									\

	addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);		\

	if (addr)							\

		addr = (kprobe_opcode_t *)ppc_function_entry(addr);	\

}

#elif defined(PPC64_ELF_ABI_v1)

/*

 * 64bit powerpc ABIv1 uses function descriptors:

 * - Check for the dot variant of the symbol first.

 * - If that fails, try looking up the symbol provided.

 *

 * This ensures we always get to the actual symbol and not the descriptor.

 * Also handle <module:symbol> format.

 */

#define kprobe_lookup_name(name, addr)					\

{									\

	char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN];		\

	const char *modsym;							\

	bool dot_appended = false;					\

	if ((modsym = strchr(name, ':')) != NULL) {			\

		modsym++;						\

		if (*modsym != '\0' && *modsym != '.') {		\

			/* Convert to <module:.symbol> */		\

			strncpy(dot_name, name, modsym - name);		\

			dot_name[modsym - name] = '.';			\

			dot_name[modsym - name + 1] = '\0';		\

			strncat(dot_name, modsym,			\

				sizeof(dot_name) - (modsym - name) - 2);\

			dot_appended = true;				\

		} else {						\

			dot_name[0] = '\0';				\

			strncat(dot_name, name, sizeof(dot_name) - 1);	\

		}							\

	} else if (name[0] != '.') {					\

		dot_name[0] = '.';					\

		dot_name[1] = '\0';					\

		strncat(dot_name, name, KSYM_NAME_LEN - 2);		\

		dot_appended = true;					\

	} else {							\

		dot_name[0] = '\0';					\

		strncat(dot_name, name, KSYM_NAME_LEN - 1);		\

	}								\

	addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name);	\

	if (!addr && dot_appended) {					\

		/* Let's try the original non-dot symbol lookup	*/	\

		addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);	\

	}								\

}

#endif



#define flush_insn_slot(p)	do { } while (0)

#define kretprobe_blacklist_size 0
@@ -156,6 +103,16 @@ extern int kprobe_exceptions_notify(struct notifier_block *self, 
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);

extern int kprobe_handler(struct pt_regs *regs);

extern int kprobe_post_handler(struct pt_regs *regs);

#ifdef CONFIG_KPROBES_ON_FTRACE

extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs,

			   struct kprobe_ctlblk *kcb);

#else

static inline int skip_singlestep(struct kprobe *p, struct pt_regs *regs,

				  struct kprobe_ctlblk *kcb)

{

	return 0;

}

#endif

#else

static inline int kprobe_handler(struct pt_regs *regs) { return 0; }

static inline int kprobe_post_handler(struct pt_regs *regs) { return 0; }

arch/powerpc/kernel/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -97,6 +97,7 @@ obj-$(CONFIG_BOOTX_TEXT) += btext.o 
obj-$(CONFIG_SMP)		+= smp.o

obj-$(CONFIG_KPROBES)		+= kprobes.o

obj-$(CONFIG_OPTPROBES)		+= optprobes.o optprobes_head.o

obj-$(CONFIG_KPROBES_ON_FTRACE)	+= kprobes-ftrace.o

obj-$(CONFIG_UPROBES)		+= uprobes.o

obj-$(CONFIG_PPC_UDBG_16550)	+= legacy_serial.o udbg_16550.o

obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
@@ -150,6 +151,8 @@ GCOV_PROFILE_machine_kexec_32.o := n 
UBSAN_SANITIZE_machine_kexec_32.o := n

GCOV_PROFILE_kprobes.o := n

UBSAN_SANITIZE_kprobes.o := n

GCOV_PROFILE_kprobes-ftrace.o := n

UBSAN_SANITIZE_kprobes-ftrace.o := n

UBSAN_SANITIZE_vdso.o := n



extra-$(CONFIG_PPC_FPU)		+= fpu.o

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