| Message ID | 20180529065100.2017-1-naveen.n.rao@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 59fe7eaf3598a89cbcd72e645b1d08afd76f7b29 |
| Headers | show |
| Series | powerpc64/module elfv1: Set opd addresses after module relocation | expand |
On Tue, 2018-05-29 at 06:51:00 UTC, "Naveen N. Rao" wrote: > module_frob_arch_sections() is called before the module is moved to its > final location. The function descriptor section addresses we are setting > here are thus invalid. Fix this by processing opd section during > module_finalize() > > Fixes: 5633e85b2c313 ("powerpc64: Add .opd based function descriptor dereference") > Cc: stable@vger.kernel.org # v4.16 > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/59fe7eaf3598a89cbcd72e645b1d08 cheers
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c index 3f7ba0f5bf29..fc9fa24cfe05 100644 --- a/arch/powerpc/kernel/module.c +++ b/arch/powerpc/kernel/module.c @@ -72,6 +72,14 @@ int module_finalize(const Elf_Ehdr *hdr, do_feature_fixups(powerpc_firmware_features, (void *)sect->sh_addr, (void *)sect->sh_addr + sect->sh_size); + +#ifdef PPC64_ELF_ABI_v1 + sect = find_section(hdr, sechdrs, ".opd"); + if (sect != NULL) { + me->arch.start_opd = sect->sh_addr; + me->arch.end_opd = sect->sh_addr + sect->sh_size; + } +#endif #endif sect = find_section(hdr, sechdrs, "__lwsync_fixup"); diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index f7667e2ebfcb..a45204b48d56 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -360,11 +360,6 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr, else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0) dedotify_versions((void *)hdr + sechdrs[i].sh_offset, sechdrs[i].sh_size); - else if (!strcmp(secstrings + sechdrs[i].sh_name, ".opd")) { - me->arch.start_opd = sechdrs[i].sh_addr; - me->arch.end_opd = sechdrs[i].sh_addr + - sechdrs[i].sh_size; - } /* We don't handle .init for the moment: rename to _init */ while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init")))
module_frob_arch_sections() is called before the module is moved to its final location. The function descriptor section addresses we are setting here are thus invalid. Fix this by processing opd section during module_finalize() Fixes: 5633e85b2c313 ("powerpc64: Add .opd based function descriptor dereference") Cc: stable@vger.kernel.org # v4.16 Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- This can easily be seen by doing: $ sudo perf probe -L module_frob_arch_sections | grep -A5 opd 20 else if (!strcmp(secstrings + sechdrs[i].sh_name, ".opd")) { 21 me->arch.start_opd = sechdrs[i].sh_addr; 22 me->arch.end_opd = sechdrs[i].sh_addr + sechdrs[i].sh_size; } /* We don't handle .init for the moment: rename to _init */ 27 while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init"))) $ sudo perf probe module_frob_arch_sections:27 me-\>arch.start_opd me-\>arch.end_opd Added new events: probe:module_frob_arch_sections (on module_frob_arch_sections:27 with start_opd=me->arch.start_opd end_opd=me->arch.end_opd) probe:module_frob_arch_sections_1 (on module_frob_arch_sections:27 with start_opd=me->arch.start_opd end_opd=me->arch.end_opd) You can now use it in all perf tools, such as: perf record -e probe:module_frob_arch_sections_1 -aR sleep 1 $ sudo perf record -e probe:* modprobe kprobe_example [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.011 MB perf.data (48 samples) ] $ sudo perf script modprobe 10463 [001] 311838.332208: probe:module_frob_arch_sections: (c000000000043b0c) start_opd=0xd000000000910750 end_opd=0xd0000000009107a0 modprobe 10463 [001] 311838.332209: probe:module_frob_arch_sections: (c000000000043b0c) start_opd=0xd000000000910750 end_opd=0xd0000000009107a0 $ sudo cat /proc/modules | grep kprobe_example kprobe_example 3716 0 - Live 0xd000000000970000 With this patch, probing on module_finalize() shows the expected values. - Naveen arch/powerpc/kernel/module.c | 8 ++++++++ arch/powerpc/kernel/module_64.c | 5 ----- 2 files changed, 8 insertions(+), 5 deletions(-)