Commit c19a5f35 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Ingo Molnar

x86/e820/32: Fix e820_search_gap() error handling on x86-32

GCC correctly points out that on 32-bit kernels, e820_search_gap()
not finding a start now leads to pci_mem_start ('gapstart') being set to an
uninitialized value:

  arch/x86/kernel/e820.c: In function 'e820_setup_gap':
  arch/x86/kernel/e820.c:641:16: error: 'gapstart' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This restores the behavior from before this cleanup:

  b4ed1d15 ("x86/e820: Make e820_search_gap() static and remove unused variables")

... defaulting to address 0x10000000 if nothing was found.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Fixes: b4ed1d15 ("x86/e820: Make e820_search_gap() static and remove unused variables")
Link: http://lkml.kernel.org/r/20170111144926.695369-1-arnd@arndb.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 1e620f9b
...@@ -626,14 +626,16 @@ __init void e820_setup_gap(void) ...@@ -626,14 +626,16 @@ __init void e820_setup_gap(void)
gapsize = 0x400000; gapsize = 0x400000;
found = e820_search_gap(&gapstart, &gapsize); found = e820_search_gap(&gapstart, &gapsize);
#ifdef CONFIG_X86_64
if (!found) { if (!found) {
#ifdef CONFIG_X86_64
gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024; gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
printk(KERN_ERR printk(KERN_ERR
"e820: cannot find a gap in the 32bit address range\n" "e820: cannot find a gap in the 32bit address range\n"
"e820: PCI devices with unassigned 32bit BARs may break!\n"); "e820: PCI devices with unassigned 32bit BARs may break!\n");
} #else
gapstart = 0x10000000;
#endif #endif
}
/* /*
* e820_reserve_resources_late protect stolen RAM already * e820_reserve_resources_late protect stolen RAM already
......
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