From 8558171b4c586bba0b4e02f7b2785720357f357e Mon Sep 17 00:00:00 2001 From: Jeremy Linton Date: Mon, 19 Aug 2019 17:29:15 +0800 Subject: [PATCH] ACPI/PPTT: Modify node flag detection to find last IDENTICAL mainline inclusion from mainline-5.3-rc1 commit ed2b664fcc80 category: feature bugzilla: 16072 CVE: NA --------------------------- The ACPI specification implies that the IDENTICAL flag should be set on all non leaf nodes where the children are identical. This means that we need to be searching for the last node with the identical flag set rather than the first one. Since this flag is also dependent on the table revision, we need to add a bit of extra code to verify the table revision, and the next node's state in the traversal. Since we want to avoid function pointers here, lets just special case the IDENTICAL flag. Tested-by: Hanjun Gou Reviewed-by: Sudeep Holla Signed-off-by: Jeremy Linton Acked-by: Rafael J. Wysocki Signed-off-by: Hongbo Yao Reviewed-by: Hanjun Guo Signed-off-by: Yang Yingliang --- drivers/acpi/pptt.c | 35 +++++++++++++++++++++++++++++------ 1 file changed, 29 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index da031b1df6f5..068dc5bdc7ab 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -429,17 +429,40 @@ static void cache_setup_acpi_cpu(struct acpi_table_header *table, } } +static bool flag_identical(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *cpu) +{ + struct acpi_pptt_processor *next; + + /* heterogeneous machines must use PPTT revision > 1 */ + if (table_hdr->revision < 2) + return false; + + /* Locate the last node in the tree with IDENTICAL set */ + if (cpu->flags & ACPI_PPTT_ACPI_IDENTICAL) { + next = fetch_pptt_node(table_hdr, cpu->parent); + if (!(next && next->flags & ACPI_PPTT_ACPI_IDENTICAL)) + return true; + } + + return false; +} + /* Passing level values greater than this will result in search termination */ #define PPTT_ABORT_PACKAGE 0xFF -static struct acpi_pptt_processor *acpi_find_processor_package_id(struct acpi_table_header *table_hdr, - struct acpi_pptt_processor *cpu, - int level, int flag) +static struct acpi_pptt_processor *acpi_find_processor_tag(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *cpu, + int level, int flag) { struct acpi_pptt_processor *prev_node; while (cpu && level) { - if (cpu->flags & flag) + /* special case the identical flag to find last identical */ + if (flag == ACPI_PPTT_ACPI_IDENTICAL) { + if (flag_identical(table_hdr, cpu)) + break; + } else if (cpu->flags & flag) break; pr_debug("level %d\n", level); prev_node = fetch_pptt_node(table_hdr, cpu->parent); @@ -472,8 +495,8 @@ static int topology_get_acpi_cpu_tag(struct acpi_table_header *table, cpu_node = acpi_find_processor_node(table, acpi_cpu_id); if (cpu_node) { - cpu_node = acpi_find_processor_package_id(table, cpu_node, - level, flag); + cpu_node = acpi_find_processor_tag(table, cpu_node, + level, flag); /* * As per specification if the processor structure represents * an actual processor, then ACPI processor ID must be valid. -- GitLab