diff options
Diffstat (limited to 'libre/linux-libre/fix-memblock-3.3.x.patch')
-rw-r--r-- | libre/linux-libre/fix-memblock-3.3.x.patch | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/libre/linux-libre/fix-memblock-3.3.x.patch b/libre/linux-libre/fix-memblock-3.3.x.patch new file mode 100644 index 000000000..3f6c984f4 --- /dev/null +++ b/libre/linux-libre/fix-memblock-3.3.x.patch @@ -0,0 +1,65 @@ +From: Tejun Heo <tj <at> kernel.org> +Subject: [PATCH 3.4-rc3] memblock: memblock should be able to handle zero length operations +Newsgroups: gmane.linux.kernel, gmane.linux.kernel.stable +Date: 2012-04-20 15:31:34 GMT (2 days, 14 hours and 59 minutes ago) +24aa07882b "memblock, x86: Replace memblock_x86_reserve/free_range() +with generic ones" replaced x86 specific memblock operations with the +generic ones; unfortunately, it lost zero length operation handling in +the process making the kernel panic if somebody tries to reserve zero +length area. + +There isn't much to be gained by being cranky to zero length +operations and panicking is almost the worst response. Drop the +BUG_ON() in memblock_reserve() and update +memblock_add_region/isolate_range() so that all zero length operations +are handled as noops. + +Signed-off-by: Tejun Heo <tj <at> kernel.org> +Cc: stable <at> vger.kernel.org +Reported-by: Valere Monseur <valere.monseur <at> ymail.com> +Bisected-by: Joseph Freeman <jfree143dev <at> gmail.com> +Tested-by: Joseph Freeman <jfree143dev <at> gmail.com> +Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43098 +--- +This is causing early panics if anyone tries to reserve zero len area, +which unfortunately isn't too uncommon depending on BIOS. The fix is +fairly safe. Unsure which tree it should go through. Cc'ing Linus +and Ingo. + +Thanks. + + mm/memblock.c | 7 ++++++- + 1 file changed, 6 insertions(+), 1 deletion(-) + +diff --git a/mm/memblock.c b/mm/memblock.c +index 99f2855..a44eab3 100644 +--- a/mm/memblock.c ++++ b/mm/memblock.c +@@ -330,6 +330,9 @@ static int __init_memblock memblock_add_region(struct memblock_type *type, + phys_addr_t end = base + memblock_cap_size(base, &size); + int i, nr_new; + ++ if (!size) ++ return 0; ++ + /* special case for empty array */ + if (type->regions[0].size == 0) { + WARN_ON(type->cnt != 1 || type->total_size); +@@ -430,6 +433,9 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, + + *start_rgn = *end_rgn = 0; + ++ if (!size) ++ return 0; ++ + /* we'll create at most two more regions */ + while (type->cnt + 2 > type->max) + if (memblock_double_array(type) < 0) +@@ -514,7 +520,6 @@ int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size) + (unsigned long long)base, + (unsigned long long)base + size, + (void *)_RET_IP_); +- BUG_ON(0 == size); + + return memblock_add_region(_rgn, base, size, MAX_NUMNODES); + } |