Commit 8385a6a3 authored by Haren Myneni's avatar Haren Myneni Committed by Paul Mackerras
Browse files

[PATCH] powerpc: Fix kdump copy regs and dynamic allocate per-cpu crash notes 



- This contains the arch specific changes for the following the
kdump generic fixes which were already accepted in the upstream.
       .   Capturing CPU registers (for the case of 'panic' and invoking
the dump using 'sysrq-trigger') from a function (stack frame) which will
be not be available during the kdump boot. Hence, might result in
invalid stack trace.
       .   Dynamically allocating per cpu ELF notes section instead of
statically for NR_CPUS.

- Fix the compiler warning in prom_init.c.

Signed-off-by: default avatarHaren Myneni <haren@us.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 9216ad8c

arch/powerpc/kernel/crash.c

+5 −72
Original line number Diff line number Diff line
@@ -84,7 +84,10 @@ static void crash_save_this_cpu(struct pt_regs *regs, int cpu) 
	 * squirrelled away.  ELF notes happen to provide

	 * all of that that no need to invent something new.

	 */

	buf = &crash_notes[cpu][0];

	buf = (u32*)per_cpu_ptr(crash_notes, cpu);

	if (!buf) 

		return;



	memset(&prstatus, 0, sizeof(prstatus));

	prstatus.pr_pid = current->pid;

	elf_core_copy_regs(&prstatus.pr_reg, regs);
@@ -93,76 +96,6 @@ static void crash_save_this_cpu(struct pt_regs *regs, int cpu) 
	final_note(buf);

}



/* FIXME Merge this with xmon_save_regs ?? */

static inline void crash_get_current_regs(struct pt_regs *regs)

{

	unsigned long tmp1, tmp2;



	__asm__ __volatile__ (

		"std    0,0(%2)\n"

		"std    1,8(%2)\n"

		"std    2,16(%2)\n"

		"std    3,24(%2)\n"

		"std    4,32(%2)\n"

		"std    5,40(%2)\n"

		"std    6,48(%2)\n"

		"std    7,56(%2)\n"

		"std    8,64(%2)\n"

		"std    9,72(%2)\n"

		"std    10,80(%2)\n"

		"std    11,88(%2)\n"

		"std    12,96(%2)\n"

		"std    13,104(%2)\n"

		"std    14,112(%2)\n"

		"std    15,120(%2)\n"

		"std    16,128(%2)\n"

		"std    17,136(%2)\n"

		"std    18,144(%2)\n"

		"std    19,152(%2)\n"

		"std    20,160(%2)\n"

		"std    21,168(%2)\n"

		"std    22,176(%2)\n"

		"std    23,184(%2)\n"

		"std    24,192(%2)\n"

		"std    25,200(%2)\n"

		"std    26,208(%2)\n"

		"std    27,216(%2)\n"

		"std    28,224(%2)\n"

		"std    29,232(%2)\n"

		"std    30,240(%2)\n"

		"std    31,248(%2)\n"

		"mfmsr  %0\n"

		"std    %0, 264(%2)\n"

		"mfctr  %0\n"

		"std    %0, 280(%2)\n"

		"mflr   %0\n"

		"std    %0, 288(%2)\n"

		"bl     1f\n"

	"1:      mflr   %1\n"

		"std    %1, 256(%2)\n"

		"mtlr   %0\n"

		"mfxer  %0\n"

		"std    %0, 296(%2)\n"

		: "=&r" (tmp1), "=&r" (tmp2)

		: "b" (regs));

}



/* We may have saved_regs from where the error came from

 * or it is NULL if via a direct panic().

 */

static void crash_save_self(struct pt_regs *saved_regs)

{

	struct pt_regs regs;

	int cpu;



	cpu = smp_processor_id();

	if (saved_regs)

		memcpy(&regs, saved_regs, sizeof(regs));

	else

		crash_get_current_regs(&regs);

	crash_save_this_cpu(&regs, cpu);

}



#ifdef CONFIG_SMP

static atomic_t waiting_for_crash_ipi;
@@ -260,5 +193,5 @@ void default_machine_crash_shutdown(struct pt_regs *regs) 
	 */

	crashing_cpu = smp_processor_id();

	crash_kexec_prepare_cpus();

	crash_save_self(regs);

	crash_save_this_cpu(regs, crashing_cpu);

}

arch/powerpc/kernel/prom_init.c

+2 −1
Original line number Diff line number Diff line
@@ -605,7 +605,8 @@ static void __init early_cmdline_parse(void) 
	opt = strstr(RELOC(prom_cmd_line), RELOC("crashkernel="));

	if (opt) {

		opt += 12;

		RELOC(prom_crashk_size) = prom_memparse(opt, &opt);

		RELOC(prom_crashk_size) = 

			prom_memparse(opt, (const char **)&opt);



		if (ALIGN(RELOC(prom_crashk_size), 0x1000000) !=

			RELOC(prom_crashk_size)) {

include/asm-powerpc/kexec.h

+73 −12
Original line number Diff line number Diff line
@@ -31,12 +31,80 @@ 
#define KEXEC_ARCH KEXEC_ARCH_PPC

#endif



#define HAVE_ARCH_COPY_OLDMEM_PAGE



#ifndef __ASSEMBLY__



#ifdef CONFIG_KEXEC



#ifdef __powerpc64__

/*

 * This function is responsible for capturing register states if coming

 * via panic or invoking dump using sysrq-trigger.

 */

static inline void crash_setup_regs(struct pt_regs *newregs,

					struct pt_regs *oldregs)

{

	if (oldregs)

		memcpy(newregs, oldregs, sizeof(*newregs));

	else {

		/* FIXME Merge this with xmon_save_regs ?? */

		unsigned long tmp1, tmp2;

		__asm__ __volatile__ (

			"std    0,0(%2)\n"

			"std    1,8(%2)\n"

			"std    2,16(%2)\n"

			"std    3,24(%2)\n"

			"std    4,32(%2)\n"

			"std    5,40(%2)\n"

			"std    6,48(%2)\n"

			"std    7,56(%2)\n"

			"std    8,64(%2)\n"

			"std    9,72(%2)\n"

			"std    10,80(%2)\n"

			"std    11,88(%2)\n"

			"std    12,96(%2)\n"

			"std    13,104(%2)\n"

			"std    14,112(%2)\n"

			"std    15,120(%2)\n"

			"std    16,128(%2)\n"

			"std    17,136(%2)\n"

			"std    18,144(%2)\n"

			"std    19,152(%2)\n"

			"std    20,160(%2)\n"

			"std    21,168(%2)\n"

			"std    22,176(%2)\n"

			"std    23,184(%2)\n"

			"std    24,192(%2)\n"

			"std    25,200(%2)\n"

			"std    26,208(%2)\n"

			"std    27,216(%2)\n"

			"std    28,224(%2)\n"

			"std    29,232(%2)\n"

			"std    30,240(%2)\n"

			"std    31,248(%2)\n"

			"mfmsr  %0\n"

			"std    %0, 264(%2)\n"

			"mfctr  %0\n"

			"std    %0, 280(%2)\n"

			"mflr   %0\n"

			"std    %0, 288(%2)\n"

			"bl     1f\n"

		"1:     mflr   %1\n"

			"std    %1, 256(%2)\n"

			"mtlr   %0\n"

			"mfxer  %0\n"

			"std    %0, 296(%2)\n"

			: "=&r" (tmp1), "=&r" (tmp2)

			: "b" (newregs));

	}

}

#else

/*

 * Provide a dummy definition to avoid build failures. Will remain

 * empty till crash dump support is enabled.

 */

static inline void crash_setup_regs(struct pt_regs *newregs,

					struct pt_regs *oldregs) { }

#endif /* !__powerpc64 __ */



#ifndef __ASSEMBLY__

#define MAX_NOTE_BYTES 1024



#ifdef __powerpc64__
@@ -53,14 +121,7 @@ extern void default_machine_kexec(struct kimage *image); 
extern int default_machine_kexec_prepare(struct kimage *image);

extern void default_machine_crash_shutdown(struct pt_regs *regs);



#endif /* !CONFIG_KEXEC */



/*

 * Provide a dummy definition to avoid build failures. Will remain

 * empty till crash dump support is enabled.

 */

static inline void crash_setup_regs(struct pt_regs *newregs,

					struct pt_regs *oldregs) { }

#endif /* ! __ASSEMBLY__ */

#endif /* CONFIG_KEXEC */

#endif /* __KERNEL__ */

#endif /* _ASM_POWERPC_KEXEC_H */

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