On 2023/08/18 18:50, Song Shuai wrote: > From: Song Shuai <suagrfillet@xxxxxxxxx> > > This patch adds KASLR support for Crash to analyze KASLR-ed vmcore > since RISC-V Linux is already sufficiently prepared for KASLR [1]. > > With this patch, even if the Crash '--kaslr' option is not set or Linux > CONFIG_RANDOMIZE_BASE is not configured, the 'derive_kaslr_offset()' > function will always work to calculate 'kt->relocate' which serves to > update the kernel virtual address. > > Testing in Qemu rv64 virt, kernel log outputed the kernel offset: > > [ 121.214447] SMP: stopping secondary CPUs > [ 121.215445] Kernel Offset: 0x37c00000 from 0xffffffff80000000 > [ 121.216312] Starting crashdump kernel... > [ 121.216585] Will call new kernel at 94800000 from hart id 0 > [ 121.216834] FDT image at 9c7fd000 > [ 121.216982] Bye... > > Running crash with `-d 1` option and without `--kaslr` option, > we get the right `kt->relocate` and kernel link addr: > > $ ../crash/crash -d 1 vmlinux vmcore_kaslr_0815 > ... > KASLR: > _stext from vmlinux: ffffffff80002000 > _stext from vmcoreinfo: ffffffffb7c02000 > relocate: 37c00000 (892MB) > vmemmap : 0xff1c000000000000 - 0xff20000000000000 > vmalloc : 0xff20000000000000 - 0xff60000000000000 > mudules : 0xffffffff3952f000 - 0xffffffffb7c00000 > lowmem : 0xff60000000000000 - > kernel link addr : 0xffffffffb7c00000 > ... > KERNEL: /home/song/9_linux/linux/00_rv_kaslr/vmlinux > DUMPFILE: /tmp/hello/vmcore_kaslr_0815 > CPUS: 2 > DATE: Tue Aug 15 16:36:15 CST 2023 > UPTIME: 00:02:01 > LOAD AVERAGE: 0.40, 0.23, 0.09 > TASKS: 63 > NODENAME: stage4.fedoraproject.org > RELEASE: 6.5.0-rc3-00008-gad18dee423ac > VERSION: #17 SMP Tue Aug 15 14:41:12 CST 2023 > MACHINE: riscv64 (unknown Mhz) > MEMORY: 511.8 MB > PANIC: "Kernel panic - not syncing: sysrq triggered crash" > PID: 160 > COMMAND: "bash" > TASK: ff6000000152bac0 [THREAD_INFO: ff6000000152bac0] > CPU: 1 > STATE: TASK_RUNNING (PANIC) > crash> > > [1]: https://lore.kernel.org/linux-riscv/20230722123850.634544-1-alexghiti@xxxxxxxxxxxx/ > > Signed-off-by: Song Shuai <suagrfillet@xxxxxxxxx> > Reviewed-by: Guo Ren <guoren@xxxxxxxxxx> > > --- > Changes since V1: > https://lore.kernel.org/linux-riscv/20230815104800.705753-1-songshuaishuai@xxxxxxxxxxx/ > - supplement the output of my Crash test in the commit-msg > - add the Reviewed-by from Guo > > --- > main.c | 2 +- > riscv64.c | 11 +++++++++++ > symbols.c | 4 ++-- > 3 files changed, 14 insertions(+), 3 deletions(-) > > diff --git a/main.c b/main.c > index b278c22..0c6e595 100644 > --- a/main.c > +++ b/main.c > @@ -228,7 +228,7 @@ main(int argc, char **argv) > } else if (STREQ(long_options[option_index].name, "kaslr")) { > if (!machine_type("X86_64") && > !machine_type("ARM64") && !machine_type("X86") && > - !machine_type("S390X")) > + !machine_type("S390X") && !machine_type("RISCV64")) > error(INFO, "--kaslr not valid " > "with this machine type.\n"); > else if (STREQ(optarg, "auto")) > diff --git a/riscv64.c b/riscv64.c > index a02f75a..288c7ae 100644 > --- a/riscv64.c > +++ b/riscv64.c > @@ -378,6 +378,9 @@ static void riscv64_get_va_range(struct machine_specific *ms) > } else > goto error; > > + if ((kt->flags2 & KASLR) && (kt->flags & RELOC_SET)) > + ms->kernel_link_addr += (kt->relocate * -1); > + > /* > * From Linux 5.13, the kernel mapping is moved to the last 2GB > * of the address space, modules use the 2GB memory range right > @@ -1360,6 +1363,14 @@ riscv64_init(int when) > > machdep->verify_paddr = generic_verify_paddr; > machdep->ptrs_per_pgd = PTRS_PER_PGD; > + > + /* > + * Even if CONFIG_RANDOMIZE_BASE is not configured, > + * derive_kaslr_offset() should work and set > + * kt->relocate to 0 > + */ > + if (!kt->relocate && !(kt->flags2 & (RELOC_AUTO|KASLR))) > + kt->flags2 |= (RELOC_AUTO|KASLR); > break; > > case PRE_GDB: > diff --git a/symbols.c b/symbols.c > index 876be7a..8e8b4c3 100644 > --- a/symbols.c > +++ b/symbols.c > @@ -629,7 +629,7 @@ kaslr_init(void) > char *string; > > if ((!machine_type("X86_64") && !machine_type("ARM64") && !machine_type("X86") && > - !machine_type("S390X")) || (kt->flags & RELOC_SET)) > + !machine_type("S390X") && !machine_type("RISCV64")) || (kt->flags & RELOC_SET)) > return; > > if (!kt->vmcoreinfo._stext_SYMBOL && > @@ -795,7 +795,7 @@ store_symbols(bfd *abfd, int dynamic, void *minisyms, long symcount, > } else if (!(kt->flags & RELOC_SET)) > kt->flags |= RELOC_FORCE; > } else if (machine_type("X86_64") || machine_type("ARM64") || > - machine_type("S390X")) { > + machine_type("S390X") || machine_type("RISCV64")) { > if ((kt->flags2 & RELOC_AUTO) && !(kt->flags & RELOC_SET)) > derive_kaslr_offset(abfd, dynamic, from, > fromend, size, store); Thanks, applied. https://github.com/crash-utility/crash/commit/1aa93cd33fa11f9d9bc9dc7e6a698d690fdd1bb3 Kazu -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/crash-utility Contribution Guidelines: https://github.com/crash-utility/crash/wiki
