The patch titled Subject: resource: make sure requested range is included in the root range has been removed from the -mm tree. Its filename was resource-make-sure-requested-range-is-included-in-the-root-range.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Octavian Purdila <octavian.purdila@xxxxxxxxx> Subject: resource: make sure requested range is included in the root range When the requested range is outside of the root range the logic in __reserve_region_with_split will cause an infinite recursion which will overflow the stack as seen in the warning bellow. This particular stack overflow was caused by requesting the (100000000-107ffffff) range while the root range was (0-ffffffff). In this case __request_resource would return the whole root range as conflict range (i.e. 0-ffffffff). Then, the logic in __reserve_region_with_split would continue the recursion requesting the new range as (conflict->end+1, end) which incidentally in this case equals the originally requested range. This patch aborts looking for an usable range when the request does not intersect with the root range. When the request partially overlaps with the root range, it ajust the request to fall in the root range and then continues with the new request. When the request is modified or aborted errors and a stack trace are logged to allow catching the errors in the upper layers. [ 5.968374] WARNING: at kernel/sched.c:4129 sub_preempt_count+0x63/0x89() [ 5.975150] Modules linked in: [ 5.978184] Pid: 1, comm: swapper Not tainted 3.0.22-mid27-00004-gb72c817 #46 [ 5.985324] Call Trace: [ 5.987759] [<c1039dfc>] ? console_unlock+0x17b/0x18d [ 5.992891] [<c1039620>] warn_slowpath_common+0x48/0x5d [ 5.998194] [<c1031758>] ? sub_preempt_count+0x63/0x89 [ 6.003412] [<c1039644>] warn_slowpath_null+0xf/0x13 [ 6.008453] [<c1031758>] sub_preempt_count+0x63/0x89 [ 6.013499] [<c14d60c4>] _raw_spin_unlock+0x27/0x3f [ 6.018453] [<c10c6349>] add_partial+0x36/0x3b [ 6.022973] [<c10c7c0a>] deactivate_slab+0x96/0xb4 [ 6.027842] [<c14cf9d9>] __slab_alloc.isra.54.constprop.63+0x204/0x241 [ 6.034456] [<c103f78f>] ? kzalloc.constprop.5+0x29/0x38 [ 6.039842] [<c103f78f>] ? kzalloc.constprop.5+0x29/0x38 [ 6.045232] [<c10c7dc9>] kmem_cache_alloc_trace+0x51/0xb0 [ 6.050710] [<c103f78f>] ? kzalloc.constprop.5+0x29/0x38 [ 6.056100] [<c103f78f>] kzalloc.constprop.5+0x29/0x38 [ 6.061320] [<c17b45e9>] __reserve_region_with_split+0x1c/0xd1 [ 6.067230] [<c17b4693>] __reserve_region_with_split+0xc6/0xd1 ... [ 7.179057] [<c17b4693>] __reserve_region_with_split+0xc6/0xd1 [ 7.184970] [<c17b4779>] reserve_region_with_split+0x30/0x42 [ 7.190709] [<c17a8ebf>] e820_reserve_resources_late+0xd1/0xe9 [ 7.196623] [<c17c9526>] pcibios_resource_survey+0x23/0x2a [ 7.202184] [<c17cad8a>] pcibios_init+0x23/0x35 [ 7.206789] [<c17ca574>] pci_subsys_init+0x3f/0x44 [ 7.211659] [<c1002088>] do_one_initcall+0x72/0x122 [ 7.216615] [<c17ca535>] ? pci_legacy_init+0x3d/0x3d [ 7.221659] [<c17a27ff>] kernel_init+0xa6/0x118 [ 7.226265] [<c17a2759>] ? start_kernel+0x334/0x334 [ 7.231223] [<c14d7482>] kernel_thread_helper+0x6/0x10 Signed-off-by: Octavian Purdila <octavian.purdila@xxxxxxxxx> Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx> Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/resource.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff -puN kernel/resource.c~resource-make-sure-requested-range-is-included-in-the-root-range kernel/resource.c --- a/kernel/resource.c~resource-make-sure-requested-range-is-included-in-the-root-range +++ a/kernel/resource.c @@ -7,6 +7,8 @@ * Arbitrary resource management. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/export.h> #include <linux/errno.h> #include <linux/ioport.h> @@ -791,8 +793,28 @@ void __init reserve_region_with_split(st resource_size_t start, resource_size_t end, const char *name) { + int abort = 0; + write_lock(&resource_lock); - __reserve_region_with_split(root, start, end, name); + if (root->start > start || root->end < end) { + pr_err("requested range [0x%llx-0x%llx] not in root %pr\n", + (unsigned long long)start, (unsigned long long)end, + root); + if (start > root->end || end < root->start) + abort = 1; + else { + if (end > root->end) + end = root->end; + if (start < root->start) + start = root->start; + pr_err("fixing request to [0x%llx-0x%llx]\n", + (unsigned long long)start, + (unsigned long long)end); + } + dump_stack(); + } + if (!abort) + __reserve_region_with_split(root, start, end, name); write_unlock(&resource_lock); } _ Patches currently in -mm which might be from octavian.purdila@xxxxxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html