Commit a0e45d40 authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/crash_dump: fix virtual vs physical address handling 



Signal processor STORE STATUS requires a physical address where register
contents are supposed to be written to, however the kernel must read the
data via the corresponding virtual address.

Also the allocated save_area, where register contents are copied to,
resides in virtual address space.

Fix this by using proper __pa() conversion, or correct memblock_alloc()
invocation.

Reviewed-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 39d02827

arch/s390/kernel/crash_dump.c

+1 −1
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ struct save_area * __init save_area_alloc(bool is_boot_cpu) 
{

	struct save_area *sa;



	sa = (void *) memblock_phys_alloc(sizeof(*sa), 8);

	sa = memblock_alloc(sizeof(*sa), 8);

	if (!sa)

		panic("Failed to allocate save area\n");

arch/s390/kernel/smp.c

+7 −11
Original line number Diff line number Diff line
@@ -658,26 +658,22 @@ int smp_store_status(int cpu) 
 *    deactivates the elfcorehdr= kernel parameter

 */

static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,

				     bool is_boot_cpu, unsigned long page)

				     bool is_boot_cpu, __vector128 *vxrs)

{

	__vector128 *vxrs = (__vector128 *) page;



	if (is_boot_cpu)

		vxrs = boot_cpu_vector_save_area;

	else

		__pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);

		__pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(vxrs));

	save_area_add_vxrs(sa, vxrs);

}



static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,

				     bool is_boot_cpu, unsigned long page)

				     bool is_boot_cpu, void *regs)

{

	void *regs = (void *) page;



	if (is_boot_cpu)

		copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);

	else

		__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);

		__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(regs));

	save_area_add_regs(sa, regs);

}
@@ -685,14 +681,14 @@ void __init smp_save_dump_cpus(void) 
{

	int addr, boot_cpu_addr, max_cpu_addr;

	struct save_area *sa;

	unsigned long page;

	bool is_boot_cpu;

	void *page;



	if (!(oldmem_data.start || is_ipl_type_dump()))

		/* No previous system present, normal boot. */

		return;

	/* Allocate a page as dumping area for the store status sigps */

	page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);

	page = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);

	if (!page)

		panic("ERROR: Failed to allocate %lx bytes below %lx\n",

		      PAGE_SIZE, 1UL << 31);
@@ -723,7 +719,7 @@ void __init smp_save_dump_cpus(void) 
			/* Get the CPU registers */

			smp_save_cpu_regs(sa, addr, is_boot_cpu, page);

	}

	memblock_phys_free(page, PAGE_SIZE);

	memblock_free(page, PAGE_SIZE);

	diag_amode31_ops.diag308_reset();

	pcpu_set_smt(0);

}