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author | David S. Miller <davem@davemloft.net> | 2018-05-21 23:01:54 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2018-05-21 23:01:54 +0300 |
commit | 6f6e434aa267a6030477876d89444fe3a6b7a48d (patch) | |
tree | 67755c422f1e85451aa646eae21d4c6f3f389d9f /arch/s390/kernel/nospec-branch.c | |
parent | 44c752fe584d8b9f6e0756ecffa8691677471862 (diff) | |
parent | 6741c4bb389da103c0d79ad1961884628900bfe6 (diff) | |
download | linux-6f6e434aa267a6030477876d89444fe3a6b7a48d.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.
TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.
The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.
Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/s390/kernel/nospec-branch.c')
-rw-r--r-- | arch/s390/kernel/nospec-branch.c | 44 |
1 files changed, 20 insertions, 24 deletions
diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index 46d49a11663f..8ad6a7128b3a 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -1,7 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/module.h> #include <linux/device.h> -#include <linux/cpu.h> #include <asm/nospec-branch.h> static int __init nobp_setup_early(char *str) @@ -44,24 +43,6 @@ static int __init nospec_report(void) } arch_initcall(nospec_report); -#ifdef CONFIG_SYSFS -ssize_t cpu_show_spectre_v1(struct device *dev, - struct device_attribute *attr, char *buf) -{ - return sprintf(buf, "Mitigation: __user pointer sanitization\n"); -} - -ssize_t cpu_show_spectre_v2(struct device *dev, - struct device_attribute *attr, char *buf) -{ - if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) - return sprintf(buf, "Mitigation: execute trampolines\n"); - if (__test_facility(82, S390_lowcore.alt_stfle_fac_list)) - return sprintf(buf, "Mitigation: limited branch prediction.\n"); - return sprintf(buf, "Vulnerable\n"); -} -#endif - #ifdef CONFIG_EXPOLINE int nospec_disable = IS_ENABLED(CONFIG_EXPOLINE_OFF); @@ -112,7 +93,6 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end) s32 *epo; /* Second part of the instruction replace is always a nop */ - memcpy(insnbuf + 2, (char[]) { 0x47, 0x00, 0x00, 0x00 }, 4); for (epo = start; epo < end; epo++) { instr = (u8 *) epo + *epo; if (instr[0] == 0xc0 && (instr[1] & 0x0f) == 0x04) @@ -133,18 +113,34 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end) br = thunk + (*(int *)(thunk + 2)) * 2; else continue; - if (br[0] != 0x07 || (br[1] & 0xf0) != 0xf0) + /* Check for unconditional branch 0x07f? or 0x47f???? */ + if ((br[0] & 0xbf) != 0x07 || (br[1] & 0xf0) != 0xf0) continue; + + memcpy(insnbuf + 2, (char[]) { 0x47, 0x00, 0x07, 0x00 }, 4); switch (type) { case BRCL_EXPOLINE: - /* brcl to thunk, replace with br + nop */ insnbuf[0] = br[0]; insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f); + if (br[0] == 0x47) { + /* brcl to b, replace with bc + nopr */ + insnbuf[2] = br[2]; + insnbuf[3] = br[3]; + } else { + /* brcl to br, replace with bcr + nop */ + } break; case BRASL_EXPOLINE: - /* brasl to thunk, replace with basr + nop */ - insnbuf[0] = 0x0d; insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f); + if (br[0] == 0x47) { + /* brasl to b, replace with bas + nopr */ + insnbuf[0] = 0x4d; + insnbuf[2] = br[2]; + insnbuf[3] = br[3]; + } else { + /* brasl to br, replace with basr + nop */ + insnbuf[0] = 0x0d; + } break; } |