On Tue, Mar 20, 2018 at 04:12:04PM -0400, Dave Anderson wrote:
>
> Hi Sergio, (and Takao and Daisuke)
>
> This patch to map_cpus_to_prstatus_kdump_cmprs():
>
> @@ -153,8 +154,13 @@ resize_note_pointers:
> dd->num_qemu_notes * sizeof(void *))) == NULL)
> error(FATAL,
> "compressed kdump: cannot realloc QEMU note pointers\n");
> + if ((dd->nt_qemucs_percpu = realloc(dd->nt_qemucs_percpu,
> + dd->num_qemu_notes * sizeof(void *))) == NULL)
> + error(FATAL,
> + "compressed kdump: cannot realloc QEMU note pointers\n");
> } else
> free(dd->nt_qemu_percpu);
> + free(dd->nt_qemucs_percpu);
> }
> }
>
> is missing brackets around the else clause, resulting in:
>
> if (machine_type("X86_64") || machine_type("X86") ||
> machine_type("ARM64")) {
> if ((dd->nt_prstatus_percpu = realloc(dd->nt_prstatus_percpu,
> dd->num_prstatus_notes * sizeof(void *))) == NULL)
> error(FATAL,
> "compressed kdump: cannot realloc NT_PRSTATUS note pointers\n");
> if (dd->num_qemu_notes) {
> if ((dd->nt_qemu_percpu = realloc(dd->nt_qemu_percpu,
> dd->num_qemu_notes * sizeof(void *))) == NULL)
> error(FATAL,
> "compressed kdump: cannot realloc QEMU note pointers\n");
> if ((dd->nt_qemucs_percpu = realloc(dd->nt_qemucs_percpu,
> dd->num_qemu_notes * sizeof(void *))) == NULL)
> error(FATAL,
> "compressed kdump: cannot realloc QEMU note pointers\n");
> } else
> free(dd->nt_qemu_percpu);
> free(dd->nt_qemucs_percpu);
> }
>
> So as soon as the realloc(dd->nt_qemucs_percpu, ...) is done, it gets free()'d.
> So I'm not sure how your testing worked, but presumably, the freed data
> remained untouched at least long enough to get the job done during
> initialization.
Ouch, thanks for catching this one. I'm not really used to mixing both
styles.
> One minor nit -- in order to be able to search for functions in a file
> by entering "^function_name", I prefer that function names always be
> placed on their own line, with the return type or void on the line above.
Ack, will keep then in mind in the future.
Sergio.
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