| Message ID | 20240708133348.3592667-2-ruanjinjie@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM: Use generic interface to simplify crashkernel reservation | expand |
On Mon, Jul 8, 2024 at 3:30 PM Jinjie Ruan <ruanjinjie@huawei.com> wrote: > If the platform do not support memory above 4G, such as 32 bit arch, > and CRASH_ADDR_LOW_MAX is equal to CRASH_ADDR_HIGH_MAX, the high > crash kernel memory reservation is meaningless and it will cause > dead loop and system stall: > > -> reserve_crashkernel_generic() and high is true > -> memblock_phys_alloc_range() fail and return 0 > -> search_end = CRASH_ADDR_LOW_MAX(same as CRASH_ADDR_HIGH_MAX) > -> call memblock_phys_alloc_range() again and fail agin. > -> search_end == CRASH_ADDR_HIGH_MAX satisfy again > ...... > > However, the current check only considers the case where > CRASH_ADDR_HIGH_MAX is greater than CRASH_ADDR_LOW_MAX. Fix it. > > Fixes: 0ab97169aa05 ("crash_core: add generic function to do reservation") > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Looks good to me: Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c index 5b2722a93a48..e18fb1bb5d28 100644 --- a/kernel/crash_reserve.c +++ b/kernel/crash_reserve.c @@ -390,6 +390,11 @@ void __init reserve_crashkernel_generic(char *cmdline, } else if (high) { search_base = CRASH_ADDR_LOW_MAX; search_end = CRASH_ADDR_HIGH_MAX; + + if (search_base >= search_end) { + pr_warn("crashkernel high memory reservation failed.\n"); + return; + } } retry: @@ -410,7 +415,8 @@ void __init reserve_crashkernel_generic(char *cmdline, * low memory, fall back to high memory, the minimum required * low memory will be reserved later. */ - if (!high && search_end == CRASH_ADDR_LOW_MAX) { + if (!high && search_end == CRASH_ADDR_LOW_MAX && + CRASH_ADDR_HIGH_MAX > CRASH_ADDR_LOW_MAX) { search_end = CRASH_ADDR_HIGH_MAX; search_base = CRASH_ADDR_LOW_MAX; crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
If the platform do not support memory above 4G, such as 32 bit arch, and CRASH_ADDR_LOW_MAX is equal to CRASH_ADDR_HIGH_MAX, the high crash kernel memory reservation is meaningless and it will cause dead loop and system stall: -> reserve_crashkernel_generic() and high is true -> memblock_phys_alloc_range() fail and return 0 -> search_end = CRASH_ADDR_LOW_MAX(same as CRASH_ADDR_HIGH_MAX) -> call memblock_phys_alloc_range() again and fail agin. -> search_end == CRASH_ADDR_HIGH_MAX satisfy again ...... However, the current check only considers the case where CRASH_ADDR_HIGH_MAX is greater than CRASH_ADDR_LOW_MAX. Fix it. Fixes: 0ab97169aa05 ("crash_core: add generic function to do reservation") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- kernel/crash_reserve.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)